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TIlAO[ · ....IlIl:
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CENTS
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CHICAGO, ILL., SATURDAY, JULY 15, 1922
Vol. II
No. I
•
RADIO TREATS CANCER
TRIODE TUBE
KNIFE CUTS
OUT GROWTH
FRENCH PLANES FLY
AND LAND BY RADIO
AUTOMAT IC AVIATION IS
IDEAL GOAL SOUGHT
~
I
S ta tion in Trial Controls Ship
Flight for More
Th an Hour
---nt
Dr. T. Howard Plank; Chicago
Surgeon, Shows Wonderful
(" fl.. dlll to R.{DJU ! 11QJ;ii n
PAR IS, PIl A " f 'F: ,- ! " .. <I,lltloo 10 con trol lt nll' I hl' tlI " h t of Iln """0l'lau1:' by Ra_
<I io . at tem l>ts an, l"' ln ~ ""we III }>',.,\I1<,e to'
d '·"J .... "' ec ha nh.m to ..nalolo II Ill;" ,e n ot
<>1\1>" to "a('e nd pil o t !.. .." b u t al ..o t o l and
A pplication
Machine Like Transm itter
w Lth o ut li n)' ha n d o n the c<,ntMI".
rx-vtcee In course of perfectlon s ho W
wond .. rful lng ..n u ll y . I n one CIl"". a mac httle without a 1)1101. It" e nglnE' ha.,·lng
b.... n Bta rtl'd, r un" acro.... the aerodrome.
call/ling to re\'oh'" at a ra"tdl)" Increasing
pace a .. mall two-bladed fan or \<l.....,w be_
t,,-f'(>n the " "l.n g " . The ran a" IWOn as it
t urn s a cer ta In n um ber o r revotu noee
a .. tua t " m...:han lsm whi ch p la c e " the control aurra... or the maehlne in Ihe r ig ht
IJO_~lt ion ror ascent. Ita manoeuver.. while
alort belne controlled by RadIo.
L and a A n w mat1c a ll7.
W h en the time con"". ro r land Ing , a
.. 11I'''al hall t he e lf eCI or unro lli ng b e n e a t h.
II" , aeroplane a len!l'lh o r w ir e . wi t h. a
' ....' h:ht at t h e end. Thh. we ight. touc hing
I/:rou n d while th e mnch lne I.. at some
ru ne helll' ht. switch .." ott the e n g in e an d
f'a u ~e .. the rear "urrac.... or the plane t o
"H t h e m ee l v PlI In !luch II ]>ollUlon that the
lan'U ng w h ee ls or the machine makes a
.. mouth contact with the grou n d.
Fr"nch Radio contret or aeroplanes has
.... hh:\·e<! already a noLllbl., triumph. A
1Itrll'e machIne wall taken up by Iu, pil ot,
who lert Ihe cont .....i" and ailo,,-ed the rna
..hln.. to be m.llnoeu,'~d tor more tha n a D
l'our by RadiO Ot>enttoMo In a 'and eta11<>.. Car belo.....
AI a gh-f'n "I.o:nal the
"Ilot r ... umed conl rol a nd landed.
Continuous High Frequency A lt ernating Current Cub and Cauteri zes Fad
WINNIPEG POUCE TO
HAVE RECEIVING SETS
L aw Enforcers of Manitoba P rovince M ay Be Equipped
W AN T AD SENT BY RA DIO ETHER. W AVES F IL L H EAD
~
-
w r~ IPE G, CA.:.'lA DA,-Plon ll a rE' under
co n e te e eart en to <'<lulp t h e W lnnl pe,l( po li c e
to rce wt t tr R a d Io p h o n e r e c e h ' l n g a ppara ·
tus, aod If Ihls me t hod o r "cn dl n g Instru c_
l io n s ! O membE'rs at m e . ror ce pro v e s 8al_
h.fa.. ! o r)'. It rn a)' b e Inaug ura ted b)' th e
,M a n it o ba pollee r orc e ,
PAGE GOLF PLAYERS
AT TEE BY AIRPHONE
E\Y Y O R K • .l U X E no-To !:ct In
touch q u ic kl y wit h trol rera o n tb e
li n ks. the Wi nged F oot Go ir C lub
1.11 conll iderl n g t he ln .llta l latlo n at .II,
Rnillo Ily"tem o n the n ew 3&_ho i", iay alit whtch Is b eln!: built at lIlarnaro_
neck_ It I" pla n n e d to have a Radio
se ndln", syst c m at t h e ctubuouse an d
a " rlll l" an d rec c l vl ll l{: flWoU o ns at each
t e e, s o Ih at member s <;.a n b 4 PliIl'E'd,
O r e gon
N e wsp a per Rec e iv e s
Advertis e ment
U nique
P icks Up H a rmle s s L una t ic with V e ry
.
Mod ern S y m p t o m s
L A K F.\· I E \\". ORK-.";herl tt W oodc o c k
r e c e n t ly I>lc k E'd UI> a man ncar Su mmer
Lake 10 "h'E' him ... rIde to t.exe v tew. The
nlan ga • hi" name ae Henry .I o hn &ul(Jon ILnd rter rldlnll' a fe'" mileol h e caU...,
the ,,~rlll"lI attention 10 the Hadlo mUlllc
comlnll rrom the ent:lne of the car. Lat .. r
he told the I<herllr lhat to e could hear ltadlo music and conYer .... Uon at aimoat any
t im e . He ah'o e:l:plalnf<l how the pietu r<'.ll
or the big «.en in the movie" ......re lak.-n.
Ill' claimed tllat thf')' ......re purred up wltb
lIa". an d "tate<! thai he underwent the
.... m e e Xll" rle nce while cro"" ln!:, t h e de...
ert. t he p icture ml'O rollo w lng him un l it
a n ol '\ >Q rt une ti m e ror tln a P I, ln l: him. The
p nor re llow was h roujl:ht t o L a k e v i e w. a nd
o n eXR m l nll tl o n w a.ll dec la r ed In san e a n d
S .. t em ror conftnement In IL
11Itf'r
Ih" " t atnl ..k ..hno sto
p lUi.1.
11'- - - - - - - - - - - - - - - - - - ·,
www.americanradiohistory.com
A1RPHONE IN GERMAN
TRAINS AND HOTELS
E n L 1:s' , OJ.:R :loIA:-', ._Radiopbon .."
will be Ina lailf<l on a number at
Important G .. rma n el<p~ Iraln~.
and T""",lvi ol': IUlItrllmenttl w ill he
1>la ced In holel" am' .. m ba"lIl",.. , aecordln l\' t o a n a n n o n ncE' men t m ade eec.. n, ly.
T ~ .. ts w ..r e m a<le r ..c e ll t ly und er t h o
oh"e n'a tl o n or .. n llln.·.. r e , military Atta che .. Ilnd t h e d lplonm U.. rep re"entn t l""a
o r the U n i t e d Slal"s a n d S wedcn .
B
..:.
J'
2
R A DI O
TREAT CANCER
(Conllnued t rom .,a gc 1)
frO"quency
c hokce,
leak, an o scill alion
gTld
con de nller. and
l r an"rorme r .
lin d a
radlallan or antenn a a mmete r. T wo b in dIng po.. t" on t h e o u u,l de 01 t h e cw.hlo",1 co r respond
to
the
ae r ial
a nd
g r o und cce -
eecueee or the Hadln tramlmi llc r.
I ne t ead , howe\'er. or Sf'n dlng the con tinuon .. Radio f req u (>ncy aUI!rnating cu ....
~nt I" t o th e ae ria l a n d ~ u n d . one b in d-
in g
1'0111
D IGE S T
lL LUST I{A T E D
Norway House and Victoria Beach Sites of T wo Ne w Stations-Will
Comm un icate wit h Airplanes P a trolling Eastern F orestsUse Ra di ophone I nstead of Code to Simplify
N
T R A D E MARK
Pu bU.h <'d WeeklY Ly R. fJ. ltA r:-':EH. r IlLU"!>..r
I~ ,,"r>lt ~h.dl .... a (;. . .... 1. CJl IC AGO. It.LISOI ~
IlCBSCIUrTlO:il RA TEa
_ U. ~ I P'on l«a
_
IllfJlll,. Cop l-. 10 Cen l"
T_ . ly
is con nec te d 10 a platinum tlpve<!.
"calpel wi th Insll h.UnK h and le . an d Ih e
oth e r to a t1.e ltlbl e metallic gro u n d ptate
u pon wbleb the pll llent III p l. coed.
Cllt. r an _ 4 Cle&Jl
I n cutt in g t h " .u.,. t h e H ad~ ""a lpel e\l ts
t~ter a nd cl ea ner than the p lMln sur1;"""'0'8 scalpel, a nd In addition t h e new
dev ice cau terlzea w ithou t burnin g a n IDlin1te>llmall y t hi n wall or U..ue 88 It cut..
>iO that no b lood llo • • .
" Il ~orm.ll t h. t t he
R.dlo curren t does the c utting:' sa id Dr.
Plank. "tor J can n o ti c e no re.lll .tance to
tbe 6C&lpel ... I d ..... It a long t h e IIn h .
Dr. Plank IIho.ed that a d u ll Rad io IllCa lpel
would ah.o c u t ..althougll n ot . . ra p ld l)' ...
o n e d rawn t o a line edge.
The Un u e can lIu lc k ly and easily he cut
Into . lIce _ o oe t h l rt Y· ft'COnd o f an In ch
in thlcknea s, a t eat requ iring the h! g h ea t
mann.... o f tklll with the o rd inary a calpel.
The Radio sealpel c u t . t hrou gh fa t tl 8AU_
the same a.s Olhe r lIuh. h u t d oe. Dot cut
oooe. Ita c u tti ng proper ti e s r e m ind one
ot t h e electr ic 0 .. o:l:y -acetyle oo torch.
W 01Ulda :B. .l "pl417
When a"ked If the w o und " o f the n ew
IlCalpel heah..1 a a ra pl<lIJ' a. tho ft ot t he
usual scal pel. 0.-. Plank replied tha t h e
beli eved the y hea led even mo re r.pldly.
due to the In lltant cau terlzatlon a n d c o n _
sequen t reUef trom co m p licating " Int ectiona. He clled • r e cent c.lle of br......t
cancer In wb. ch • lo ng and d ..ep In cision
had healed In fou r d ay ... The wa ll eeurerIud Is "'0 thin t h a t It d oca not act a .. a
detriment but r at h c r a h e ll > to I h e hea l·
Ing. ::\"0 ca r hon lsatl o n or bum.n g ot the
f1ellh by t he ne w Ro.dlo IIc a l pel Is n o tic e d .
An in terelltl n &, develo p ment o f
Dr .
P lao k 'a ex pe r i m en ts la that t h.. hl l{he r thOl
f r ..q u e n c y o f t he ap plied cu ere n t. t ue
fa"'te r and d eeper a ro the c u U l n /( p ro l>_
erti ell ot t be ecernet, a n d v Ice veeea .
lDtBrT1I.p tB d Spark B 1U"Il.
T h e d octor "howed u hi gh f r e q u e n c y
Int crr upt ed a lternalln g c u rre n t a\l p llrllt ue
which he ha il expe rlm .. nt ed With . a n ,l
wh ich c o n a ls t e d of II high t requt'n c y SlCI>
up Ir a n s t o r m e r. L e y d e n Jar", ollcl ll n ll o n
tra l..,fo r me r a n d l:f pa r k gill" The IlPlllu u t u",
wlI" like t ha t found In prll, c t!cll ll y .. ,· ny
tr"mllllllOllg ereuen be fo rOl tho th rOle ,, 1('nlf'nt ,"aCuUm tube h""u me ' IWI, u lar beca c eo ot ItII grell,( er elflc!<-ncy .
Or . Plank " howed that thc 111g h rre(Iu t'n,,)· s par k " c.. lpe l cll rbo nlzed .. nd
hurned ti s s u e >! w ith ealle. b u t would n ot
u n d .. r .m y c!rc u n,stanc es c ut t h e m . T h e
dltrer.. n cOl bel w een the t wo methud s I..
p urc ly In I he nat ure ot t h o ""euerated cur,-en t . T h c nOlW .. n d suc"cs l!lful me thod
usee a con llnueu s h lKh f reque ncy euernall ng cu r r" OI. w h il e t h .. ol d .. r m .. kOls ""'e
o f a n In le rruple d a n d dam l", d h igh tre.
'I,lfmey c u rren,:':,
_
Rddio
Digest
I llv st ra t e il
Canadian Province of Manitoba
to A dd Radio to Forest Patrol
WI :SNI P EG. CA X ADA- PI Rn e h avebeOln
d r a .n up fo r the construct Ion o f two n ew
Radio s t a tio n!! to be locat ed at Nor ....a y
H ou.. e and ....Iclorla Beach. !.\anltoba. accor d in g to y tljor B. D. H o b b" . s upe r ln_
reeeen r of the M .. nIIO..... .-\" r l.. \ Fo ~t P a .
trot,
T h e s e s tati o ns are t o comm u nica t e
...· It h t h e alrplan ..s pa i ro lllo g t h e _ .. tern
:Man llob a (ore e ts In order t hat In f onna .
tlon rega rd in g f or.... t flrea m .. y be .w!ttly
Obtain ed a n d r e la y ed to t h e District I n.PeCt o r ot Fonstry at W In n ipeg .
..u.t
J:lItend ..
_ _ II
$800
c~~
~ 11'. l PU, 01
11l1Doll, _ _ Lbo ,A.. . ell
u.o
loI-ar<tI .. t i ft .
Val II
CIlicIIa_. S._da" Jw,. U. I'll
No. I
CONTENTS
RADIO SONG FROM MID-OCEAN
Dut.. b Radl' - S ,. le lll t o Gr-; 1lo0Io
R...n.-.; R<.d.io 10 A NI hi F l.b! A.aill.l)1
80011• • • _ ; Depe ~ _ _ t S I _ Bu y ...
to T..t A _ tatu.
Tba Radloph
1e1·. M. n
Broadcull n l Stallo.. OI
•
.
l ory
.
Inet..x I.. B,....I..... I; II' Sta llo a Direc tory ·
R...... ~ill. ~d . Coa 1...t ; WSY In:
...-eaMa
s.r.,ke fill"
F.,.tn... ..
14
Q u""tio". a nd An.wer . .. . . . . . • . .... .. ...
15
,I,,_
@ IX-T.
(Arnl""'"" Rudo.lph F.lrnl sailed f~ N...... Y or k ..."",,11,. on the S.s. M.J.-tic. to !!:n h....
"'>lh FlO'..n. Z'el'feld. J.. While ,1> ",Id· - . . Mr . F r. m l ....01. a _a. d <'<!lc.atill ' it 10
Ma17 Ealo1>. ",110 wtll alII' It I II Ih. F ....I!.... MO&I of u. can' l o.In • • le t a1_ "'ri le
In ",id_OCQD. bu t in a ddi ti on Mr. Frilltl !l<od ill.talned it t o So F . IVn,.lon. Zie, 'dd·. , .....
er al
Th" "'....t Ra dio , ..In<'<! _ g In t.alllKn b<'d 1<>nIl • b......bow lI
.on,.
'nan.'.....
•
Edi tori al s- Rad io .lId Ih. W
Il-LI'h!.
nl n l: Not AU ra e1ee1 by A.ris l.; V. Ed
Aah 'imulf; Rad io Indl · c...t
An Efficle n l 511 Mrl.r Lo-. CIl'u pl
by
Adrl.n V.II Mllft1llll' n..... K.aK
R.dio T" I..ph on y for A"'.I.ur • •n d B..
II""'. . P . rt VH I- R" ..ei'O"", a .. d Loud
Sprake ... by P . t. r J . M. Clu l... ... . . .. . ..
Simpl. 11I. lru c1l0n. for B,,' I.. n...... Red lo
•
M .... urin ll In. tru men l. , by H. J . M . nt . .
P " n e! Unll . for Ynu. Re-celvln, Sd • • 1h"
Honeycom b T u nl... 1' .....1 ,," d til . V. rl o _
m<t..r V...ioc: ouplrr T un ln l: 1'....1, by
H. J . M..nq Hoo k _Up It O _C . .. . . . .... .
tc
>1
12
13
Looking Ahead
F~..-<y A",plifi""t lon. A con tin.... tion
li f'Tl ja m in F . Mi"SO M.' . u ri... .nd a
•
li m"l,. a.,i"k
Radio
0/
CHICAGO SHOW AWARDS Frenchm an Brings Out New
Radio Programs Now Keep
MANY CONTEST PRIZES
Miniature R eceiving Tube
Lighthouse Tender Happy
High School Youths Carry O ff Ma~
jor H onors at Exposition
C H ICAGO-A large a ll v.. r loving c u p.
fo ur '::0101 m &da ls . Ihr.... alh·er medals"
• nd '150 In ea"h prizes were . wa r d e d t o
w in n in g contestant. In the ...a,'loua QUm_
pe ti tion" held d uring the C hicago Radio
Ez- POel Uon wh ich ended neee July 1.
T he Ol....·a nls were B8 f ollo_ ,
E u g ento Cra ig. a u ..ndlnc l li ll e r gram·
rnar "choo l. Evan llton. 111.. • . . ...... r ded
a prl&e of ,~" .nd Co ld med.1 f or Ihe bellt
c r ystal delecto r receh' ln g ac t. w a"e len sth
ran g e t rom 175 to ~ m .. terll . made bJ'
.. n y OOy .. Ue nd l n g gramma r IIC hool.
Frank S rnal.. k" T ll d ..n h ig h &ehool. Chi.
caItO. r eceh 'e d a llrlze o f t !S and ,",101
m edal f or th.. beat cl")"IIta l d .. !ector reeet ...ln l;" ee e. . .a,'e len gth ran ce. li& to 600
m e t .. r " . c onllirueted by a boy In t h e a rli t
or ........ nd y...r of high IIChool .
J"obn Prinel... T il d en hl ll"h IIChool. Chicago. was award e d li n t prize of t~O a.n d
g o ld m f'd a l fo r maki ng the be wt r e",..ncra ·
uee detector and audIo f req uOl n c y a m p ll_
ll er rec.. lvl n l:" .l) llt . ... a,· e le u g th ""n ¥" 173
to 600 melerll. second p rh:o In thl.l!l cont e s t , $30 a n d e uvee meda l. ,,·..n t to F r ed
W .. lcott. Eva,n aton hlll h ...11001. Ev.. n aton,
II I.. an n I h lr d prl:tto . t ZQ and 1S1I\"er m eda l.
t o S. F . ~ll\rtln . C .... nc TeChn ic a l high
sehool . C hl cal"o.
"·ash b urn e Contin u ation school w on the
gold m ..dal a w.. rd ..d fo r the bOla t reeet ...l n g
.... t m ade by any ex h ib ito r dllrln g the
ellp<.>9ltlon.
For h n\'ln l; the heet nrran l:"Old llnd most
In t Cr Ols ti n l'\" b oo th. L an e T ..ch nlcal hi gh
!'chool. Ch ica go. WIlS nwa rd Ol,1 a lAr ge
enve.. lovin g Clll>. whllo CrUD" T e cl l n lea l
h ll!:h school. Ch lcl\ 1I0. wo n .a. s ll .....r medal
fo r havln c t he ...cond b e llt e :l: h l b l t .
~EWTOX. ) r,'~f'l.-o\ neW R a d io rccel\".
Ing lIel halO I>.. en In''UlIl,,,1 llt ~"rum lJl.'ll'''
' ·8 r k. a Jlopu ll<r MU,"m.. r roaort On tho
CharlOl" Hlv t' r e t A Uhu r n.l"I,·, n ll,l rC:lcl",,,
b y trollt y li n t .. a .. 'V"ll "e CUllOOlI"tll trom
a r a d Iu s 0 II t MO m ll "ll.
(8 J)U'la 1
'0 R _{ D/O D lOE ,; T)
TORONTO. CA ~ADA. - .\ n e'" " a c u u m
tube has bee n In'·ented b )· t be ma- Ier m echanic of Ihe Ellfel T o....er Radio s i a ll o n.
P atls" Fra nce. wblcb can be operated o n
on. volt ot elec t r ic currenl . a n d aU that
la n ecee ... ry to 6upply Ih ltt Is a a l m p le
f1a"hUgh t b attery. Tb '" ne .... d e t ec t or a n d
• m p1l6er tu be n ee already f o u nd lis way
10 th e Can ad ian market a nd Is t>elng IIOl d
at con llidetlthly Ie"" thsn th e p reseo t
tllbe... T h e same in -.-eotor haa pe rf.....ted
" c r y"tal d e l e c l or r eceiving se t t hai III
("llNi b le ot teCt'1 ...lng m .... " ag.... fro m a 011,,_
ren ee o r UP t o 500 miles.
When t his set wa s first e xh lb lt .d In
P ari ... f"rance. a squad of ten g .,n,la rmefl
" ... called In t o ac Uo n to k eep Ih e llpeoc·
l a l Ol'1l In ordt'r. a n d suffici e n t o rde rs for
Ihe n.. w " .. t W..re gh"en t o k e e l> the factor y
bUll)· for IWO )·ea..... T hla se l. li ke Ihe
Va" Uu m l ube, Is making ita w a y to the
Ca n a d ian market.
- - -
To E rect
Five
Radio Beac ons
\\-A SHI::\"GTOX. -Ra d lo beacons Ih a t
..en d ou t wa rn in g s ign a l" 10 ehl p s In tim....
of fog a n ,1 heavy weath .. r , will be In _
.!.a lled a l Boston, K a n t u c k e t . Cape Char i.....
Colu m bia river. Pu g e t S ound. Ih . de»ll rt·
men t ot Co mmerce h a .. ann u u n c e d . W h e n
t h ..se IIlela llalloIl!l Ilre completed. t h ere
wi ll be t e n IIgh l h o u .... Iltatlo n. broadca.. t·
In g R a diO e lgna l s trom whi ch a ny IIhl p
e q u ipped wit h the Rad io d l r ectl Oll fln d ..r
ca n dot erml "e lis ..][a ct po8l tlon. It tun da
p ermit, R a d iO beacon a w ill alao b e t nlltall ..d at IK>laware Ilay. Loa .An l{el ,," . lin d
Blun tl. n .... r. &'Idlo h elicon s a r " no w In
opOlralion at Ambro8t'. Plre Isl and and S e a
Gir t near N ew York harbor. a" d Oll Ih e
lIJ("htshll's orr Cape Hatteras and R"n Fr-ancl "'co . Many tordgn ve l",.. I" a r" nnw tn ~ lalllllll; Radio ,1lrectlon f1nd .. rlJ t h a t ....111
,·""Me them to l ake ad anlaJ("e nt tn e
1l"<!1,, ",,,.nl l11(8. 8",1 lh'·
"'" w .. U II..
Am ,' rlran ship. artl t ntoreateu In I m l)r O v~1
IlOlt\" I<'0l.
(Spc'd6l to R..f.DIO DIGEST)
Cry.t&I Detector Rreel...ln. Seb. Th .. ....1'
a rti",," b y P et.... , . M. aut.. will inl... ..", •
hOO I 01 la M p:o.. u . in. Ih.. ,.;mpl .... oct •.
P ...... Unit. I... Your RfIa'!vl... S<ou.. T wo .ddi·
l io""" ..." ..10 01 tb" olo nd ..d Iype. The- b...1
• • ,. for an .mal..Ur 10 b u ild 1l'P hill ... 1 i~
h:t' n alldan! poon ..I•.
o.s-wuuo» L. norae»,
a IIl{hlhou ,,", k et'p .. r- on a n I..olated Is la n d
In Lake F.r le . ha.s for'nrded the f o llo w ing
cutia . DiftctooT. c..t. he-II.... and la rll '"
Id t er t o Ihe c hief of the II l'\"h t h o use ser v· Broad
r;ach ......k. 111.. Onl1 co n Yt'nit'a t ...1...........
Ice . WB8hln ll"ton . D . C .• t~lIIn g h o .... he
10 .id JOIl in !indial a OIal;Oe !wa ttl .
ke-epa In tou ch w ith t he ou tside world
throu a:b a hom e _made Rad io lleL )I r . ncr - "H_ 10 Malt. ~ ....... t." )I . n,. !tillltl rn-ry
.......k a. .. ;" t......lta llll"d bt're.
.
don In h i li letter u.ylS:
pal''' ... in he•., thon l{ht you m l &"ht be Interest ed to Radio lnoulnW_ Th.. pit'I"
t.
b.1d. ;n ;,. pia.... n""t
k n o'" tha t J ha,·e 8. .. mall home_made Ra_
d io eet from w blcb 1 r ece tve. t b rough
\\"\\"J. n ad lo broot d ca llUn g IIta tlo n o f t he
OE- IreU X ...e. t h e la l .... t .orld n e ....e, the
Um ('. r . porul of IlPOr ting e vente. etc.• mu,,1<'111 co ncertll. and a tal k eve..,. morning
b y the ho ul!lehold &'dUor. g1-.-lng rc<:IPC'lI
f o r e a ch ' d a y 'lS d inner• • low> talks o n the
Ca re ot ftOWe nt an d the h ome. From \VC-"C,
of Ih .. l"Jontro lt F ..... Pre.. a s lallon. we h e ar
('o ncerta. s p......h.. a. a nd the new ... On S u nd ay l\'1 om l n p a n d ev..nht j:ll ,.... h ear I h e
se r ...I,.". of t h or St. Paul'. catbed ral ot
Detroit. t h ro u5"h Ih e hroadcastln g trta tlon
of \\"\\: 1. Aa w e do n o t l:"et ashore ve r J'
orten w e e nJQJ' all t hl.. v e l")" m uch.
CLF.:\"F.I.A~D.
I,===================
ON YOUR VACATION
You'll Want
Radio Digest
N
Airpho ne
to
Aid
Mine Rescue
PI T T S n U R GII.
P A .-Th e
Plt t ahu r l'\"h
exp.. r lm.. n t natle n o f th~ U n lt ..d State s
U u r e a u of Mi n".. F o r b e.. str.... t. Is to
b., o ne o r t wo e ..nl r .. 1 station,!! t o be
.... uIPl>'t'd wllh Rad iophone" to "peed np
mine ret,eue
n d . 8Ilfety
w ..ork,
It tlWa
nnoune"d
r Olc e n.. tiy
A west
r n IIta
o nll wa ill
be In Srolt r. n k !' Cit y.
H ilr h - p o w ., r b ro ad ClIlIUn g towe r a h.. r e
w ill recell'Ol n t'..-s or m ine acelden t s or
ll('('I ,ll' ntll In lho p" trolcum In d u. t ry and
bro r...lrn.. 1
In .. tru ctlo n s
to
1I...,.elnlly
Ol'1"!l'I'Ol<I m Ine r"" "u e and II"rely oars
lIla ln t a l n"d at 21) s tn t lona In th e country.
SUBSCRIBE NOW!
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Send
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the blank today
Pabn. ......
Red io 0 1, ...1. llI u.tnteel.
W w...t M"dl. o n 51..
Cb i"", o. l!linole.
Pi ...... 'n. d ent'!-..I ..h eck M. O. lor F lv .
Do llan I.... 0 ... v ...... Sllb..,ripUOfl t o Radi o
O;, a t, llIu . tntad.
N
Ed '\Yyn n. well-known comed ian. I" a t
w " l·k <I n II "' u..1<"1<1 comedy with a R a dio
lIl m '''' Jlh ('1"t' IIn, l "ntlt\e<l '·LI,. lenln l; In,"
I" I,,, 1'r"oI"t''' oI n.. xt fa l l. lie cont e mpla te"
bro:!l1"lIsllng p"rt or It.
In
Ir--------------------,
A ddreu
017. ,
_•••• _
.
.
State .• ••• . •. . . . •. •.
RADI O
PLAN NEW BEACON
COASTAL STATIONS
BURE AU OF ST ANDARDS
HOLDS CONFER ENCE
Manuractw"er il Given Chance to Furnish
Direction Findera-F oreign
Ships Equipped
(BpetU'
D IGEST
R1GHT·OF·WAY GIVEN
IOWAN POUCE CHIEF
AIRPHONE TIPS OFF
MOONSHINE STJLLERS
AV E N PO R T , I A ._It will m ak e no
d Jflerence It the t r au " m lt tl ull'
"ta tl o n at the P almer S Cbool o f
Chiropractic. woe. ls ea ga lred In a ll
Importanl buslneas tran aaetlo n s ho ul d
t he peltee of t h lll c ity ",Quire ths IIta_
tlon to hroa,dea.st a crtms warni n g
The chief of p olice b eli e ve s It will be
a bi g help'.
O U JS V I L I, E . K'i'. -Reyen ue \ otB"""ra >reeking etaune e.. of the flU'famed and hard-hi tting "whit!!'
ll K"h t nlo'." In the mou ntai ns of K e n
t u cky aay th at man)' raid s made It
the lallt few mont h,. have p roven 1>1'1
llUOOIlllllfu l due to the adoptio n of Ra_
d io pho ne Illl a mean 8 of C'Om m u nlcatlon amon.. tile m oonahl n 8rB.
D
L
QUEEN OF THE " HOW TO MAKE"
dlNoCli oD ft nden and ot!lclala of the Bu-
reau of Standards. repnlln g t b e prod ueUoD. COIlt, ln lllaliaHo ll, e..U bra tl o n,. and
mal ftten&rlee of tt.dl o direction ftn ders 011
IIhlpboaf'd.
It "'u u nou llced that the Depart m en t
t.o Ill s ta ll addl·
Uona l Radi o beaeoll statio...... foli o".:
Bostoll, Z'O&D!ucket. CApe Cha rles, Colu m b ia Ri ver. en t ...nee t o Pu~t So_d and,
If {un w. are atlU a va il a ble , 1'\ela" "1lJ"1Il & :J.
LooI A ....lea, and. Blunt'. Re<jf. Cali forn ia.
n _
a~ lD addltloll to t be tw o I>.W
Rad io beaeon.a at Diamond S hoal (off Cape
H atter...) and SaD F r a nc::t_
L i g ht Ve.-
ot Comme rce haa decided
Three o ther Rad io beacons b .... been
~"' '/I"
York
a ,. ear, a t Ambros e. FJre
GI rt.
I
I
1'~ Bh1P11 V i e a.d1o l;om~,
A con"lderab l" n um ber o r ro~l t;n
ha ,,!!' bHn eqU lppe-d wlth ~dld d l'reet lo n
lind en! and a re call1n s fo r J1.&d lo beece n
....r n ee- a" they apt> rolLeh Amerl e.n ahores,
AlDe r lcan "h lpt>ln g complln lee a r e etee
awak..nlng 10 th e Im po r t a nc. 'of .. " f nll' the
d JrectJon nnder o n IIhlpoo.rd; In ord!!'r t o
d etermine t he ir locations In ti me of fog
lin d In ord er t o IIld In v a r l6 da ' ,,"a Y8 tn
tim", of dll't...". at "ea.
• ••
As a tilsul t of the c onfe r ence. a rra ngem e.n ts will be made ' th rOUJlh the. LIll h t.
hml8e Se rvl..., he t",'een the m an ufa ctureMl
o f Radio d lr ee tl o n tinder. and 'the o(l(lr".
tor" of IIteamshl ps for t ho ttlill ~nd d em on Rt ra Uon of Radio d irec ti on nndlng
equ ip m en t I'rodu ced by Ihe -Bevera\ m anu factu r ers uml ..r cOlldl tl ollS of p ra ctice.
It III IIntielp ate,1 t hll t with Ih e tnllta UaUon
o r t he Ildd llion al Rad io beaeon s ta ti on s
..nd the aetlv lty o f Ihe m .. nufacturers In
t ho produc ti on of dJr.. e uce Iln d er ll for USII
on IIhl pboa r d. une m ethod wil l br a do pt ed
"e ry lI'en.... ra ll }· 0 11 on a id t o n a y ll'atlo n.
H a r bo r ror
I s la nd, and
1>\' " ''
sea
"hi"
Golf, Piano A id
Fast Code Work
Cana dian
P ITTSBURGH SCENE OF R E·
CENT ORGANIZATION
Club's Fundamental Purpose t o F it U p
Hospiub -
Non-commercial
(Spcdol t o RADIO DIGESt')
aUYN or companh:a manufacturing Rad io
In operation ill the vi cin ity ot
NEW CLUB FORMED
BY NATIONAL FANS
in Purpose
to RADIO Dca88T)
W ASn IN'G T o S'. D. C.-A ee nr ere ece
. . . be ld bera recently bet...·_ Q ropT_n l-
~I.
3
ILL U STRATED
A d v is es All Code
Increase Spe ed
by Pl ayin g
Expert
Ope rato,. to
{SP«'f'" t /l RAD IO DI0ESTI
nALIFAx. X. l'I.--eIlQ yOIl t ... n 8mU
thirty " 'Onl 8 • mln uts ? CaQ You copy
,,"""'k ",,;_18 th rou gh tn te rrerenee 'l nd
"'l aUe ! Take up c oif a Qa plano, II ths
a dYI"" gl "en b y N ova BcoUa o ptora t o rll t o
nO"I CfOS wbh l ng to Improve their CQde
......
An ,. man ....ho ean dM ye :!OO yards with
e ut slicing Or pu lllo g can 0&811,. learn to
tran " m lt Morse IIII'D.... at b lgh ,,~,
A )'S M r . W " T . 1 0 hn llt o ne. ot the Dom ln lo.. R adio ee rvt ce.
Mr. lohlUltone
roln ts ou t tha t the 8e'er e t of h l g b st>ll'lld
t r lUls m l_ lo n Ilea la t be perfe.et coordina_
t io n of mind an d body. a nd In the e eeu .... teo
C'Ontrol of t he muaclell l Q the f orearm
a nd undo Golf deve lops this sel f -cont rol
t o a ",markable deKTee . he abl.tes. while
plano playlD g IJt.re....t hens the arms and
hJlDd... S",veral opera tOn! a r e studylDC the
plaDo In. ordt' r to cure. thetnselv_ o f a
habit of s l u rrtnc Ihe more dU lleult IsUel'll
o t Ihe alphabet. wch . . \" a n d H. P lano
prs ctk'e not only cures tb ls a l urrln g bu t
dev e lo \MI III Ihe operator • s w ln&,IDII'".
r h y t b m i......1 lJt.yle o f t r .....a ml.ulo n t hat ..
e . !!lll y ooplfll a t the r ecel vln ll' station.
PITTSnUROH. PA._T hI" ci t y III t h e
scen S o f the o rpn l&aUoa of ths ~a t1onal
Rad io Cluh, The work of tnrol1l nc me m·
hero h.... a tar ted, a nd ar tlel.... of Inoorporatlen h.ve bc.oen ftled ,
While one of tb to c l u b'a fu nda m e ntal
purpo8ea I. t o promot e . Qd ftnance tbe
In s tall.tlon of Radio equipment In hospita ls. It will .1_ v ile Ito teace e ce to k ee p
t be broadcalOtl n.. . rt o n It. present h lp
pl.ne: enlulI'e m u.. lcal a nd ed ucationa l
Rad io pl"OlrTam s : ke ~ p a n m.mbe.... Ill _
formed regardl nC d. ..eloprnen ts. Im proTe_
m ent.. and news of Int.~st reprn lng Ra_
dio: an
rlIheu t o;:harge. a ll techn ical
4uelltlona
kN by ....mbe...: reeeh'e . n d
Ille artlcle a Wrl U~D b y m e m be rs for reteren o;:e ; lsnd Ihe m e ...1 e u ppor t and 11'1 _
Iluenee o f Ihe cl a b to tho llll ag enclll1l !!'ndell,'ortng 10 e llmlna t .. the eo nt ufOl o n ot
o lgllab ; a nd p romote fl'll t eralty and .. oed
f ell owship amon.. me mbera.
Tb e organh:allOl1 eeermn tee Include"
B. B. eoe, New Yo r k ; W . Pa)"De. Phtla·
delpb la : F . R. ),t cC ra,.. Loa Angel e.; s,
P.. l m, C incinnati ; R. G, Crat... R. Mansmalin, and T . 0, Al bertl<o n, P lttab u rgh,
The Club ball been ....ured CQ-OperatlOl1
from maQUf.....l ur e ... but will maintain a
.trletly ne u t r . 1 alt it ude In a ll matte ... o f
eq u ipment. It o otllc.. ra and d lnoct OI'll will
be eetec tee f r om Rad io e nth u " la " t . not ee-,
gaged In rnalr.l ng o r salling R.dlo a ppara_
.U~
FISHERMEN AGITATING
FOR RADIO EQUIPMENT
Schoone r
Puritan
O bject
Wreck Cited as
Le sso n
(Bp<"cla' , o RJ,lJW lIUJL'HT)
HALIFAX. N. S. - F o l lo w lng the wreck
of the tb. h l n!':" eeheene r- Pu rltn n. t h e Amer·
l can eha llen g"r f o r the I nlerna tlo nll.l F lah _
ermsn'lI troph y . Non, Scot ln Ih .lIe r ",en are
r equ e" tln g o wn...r . to eq u i p t h tllr v ...." e ll!l
w ith R a d io" T he y poIn t o ut the fact that
the ....reck Wo uld not h av e occ urred h a,J
t he Pur l tau been a ble to oMalA be llrln g ..
f rOID t h e Rad lo-compaas staUo nlJ at Ch e.
bueto Road. and Ca n RO. all Ita4lo-equ lpped
v _ l s f Nlq uen U,. navIg ate t h rou gh d .... o_
t og IJI. the vi cinity o f Sable I lIland. wh ere
the P urlta.n wen t ag ro u nd. with the h elp
of the ~dto-«lmp8li8 a tatlon... T'h," y a r e
also quoUn .. the l ou of the et eam er Ar ·
jeeeo. r ee..ntly w recked n ear Cal'6 Race.
N e w f o u n d lan d. In n. dtlnBe tOll'. Thla "btp,
@ P. a: A.
u_
_olil. ...i%:t
@ INT. they Claim, could have r o u na ed the cape
In p erfect sec u r it y had IIhe bee n a b le t o
Min H ope H ampt o... film a lu\ trylD..... t h .. h _
mado Nt
0.. """" .. \lI.lD; d ........... as ... com m un icate w ith t hs cape Race compass
aerial. ( .....1) Sh.w" her so ldoriro, the tuDho. eoiI
s taUo n .
The nli h ermen h a,"e a lllO peti ll oned t he
Dom inlOQ g o vO!r nment to a u p p ly a Q aerial
l>A t rol. ths ai rplanes t o look for lK'boob
SZA W IN S H OOVE R'S CUP PHANTOM NEW YORK SHOW of h errin g a nd mackerel a nd to Inf o r m Ih..
IIshl ng tleet s by Ra dio of th s pos iti on of
these lK'hools ,
-Grand
P
ala
ce
Manager
Denies
KnowlF al coni Awarded T roph y as Best
edge o f Expositi on
Ama teur
HARTFORD, CO :---:S-. _ A n Qou ncernen t
wu made recen tly by the Am e rica n Rad io
R l' la y League that the s li ver lo v ln \: co p
do nat ed by Herbert Hoo r . Secretary of
Commerce, has been a
rded h. Louls
Falcon I. of n.:.r..w el l. :N, J,L Falcon l's statloo, ~ZA . w&8 described In t he May N
lI.s ue of RADI O DIGEST. T he t roph y w ...
t o co to tbe a matel!r wlr et eQ o Pllr a t o r
....ho e on.tructed a nd oPllra t ed the mo"t
emelll,nt a mateu r atll Uo D l.n t he U nited
State" ItI 1S21.
ITHE A NT ENNA BROTHERS
X F:l\· YORK.-The ma n agement of the
G rand C",ntral Palace ....... mueh sUl'Jlrll&ed
r e<.'e n tly t o learn t hat t h"'r e
t o be a
jK'rm8llent Radio e"poslUoo
dance h ..11
IlOd t h e1l.ts r o n one entir e floo r of the ir
bulldlnJ:' and that 10 pe r cen t o r the a ~ e e
had alread y b ee n OpUOD t'<! by n adlo equ ip..
ment manufacturers. Somebody II!l e i ther
"spoon n.... t be management or el"e tbere
Ia anolher *ge t _r1e h -q1>lck" sehe me a tloat.
f o r the presi dent says th a t the re Is Q"
Radio e "POlI Ulon sched Ule d e:r eept for one
t o be h std the re In Doecember or thl'" year .
Spir L. and Lew P.
www.americanradiohistory.com
Stant Flyer A irphones
Audien ce During Flight(B)NCMI ' 0 RAOIU IJI U r. s n
A I.A. -Wlt h the lnau Il'UraUOlIl ot the Blrmlncha m Aero Club
here on the F ourt h ot .Ju ly e J:.. ~III(: " w ere
he ld a t RobE-rtll Field In .. hlch O lsnn F..
!lt e ouoer. na ti o na ll y k nown "at u n t flyer,"
co m mun ica ted by Radio ....lth the crowd
_ _ m b led o n t he neld s ll during h b SJ:_
hl bltlon. Hs pve notice du r l.. g his IlI..h t
of t h e n eJ: t s tlln t to bo pIlrformed alld
..1_ t old of h ill enet alt itu de at dlflerent
pe r iod . of hili exhibi ti o n.
BIR)U~GII AM .
A Modern Fish Story
I
4
R ADI O
DI G E ST
I L L UST RAT E D
Little Tricks Aid Panel Making
Wood Lid Knob. and
Cardboard Make Dial.
Th ere III nothing to co m pare w ith b la c k
~c;.r~~;loO:e~:.ke~~~h~~~~~ ~tr t~~:eJl~~~~
rIal . w lll tln lsh up s m oo t h and "hl n y, a nd
O'
It ofte n bec cme e n ec e s s ary to tell t t he
'lOnd enll ers or a Rad io 'let to s ee It they
a r e In workin g o r de r , T his Is a ver y
I'l lm ple matter but one wb tc h le q ui t e
li kely to give the unin it iated no end or
trouble.
connect one te rm ina l Of the condense r
to be te s te d t o on e lead trom a small dry
c e ll ba ttery an d o ne l ead e f a t e l" phone
r ec e iv er. Then touch t h e other te rm i na l
o f the cond..n ser w it h t he t ree ba ttery
lea d a nd t hen with th e tr"e l ead tram th e
p hon"s. It t he een e enee r Is In o rd er a
c lick w ill be r eg l s t ere!! In the r eeeivers
" v" t}" ti me t he p ho ne l ead I .. applied t o
t he eonden ser t e rmtnal fo llOWing the a Dplication at t he balte ry- lead . If no Cli ck
la heard the conden se r 18 n ot tunctlonine
pro perly . It rnay be t he rellult 'of tbe
IIhort circuiting d ue t o the dla le ctrlc substan ce hav ing b roken dO\lT1l. or In ease of
a varia ble t y pe, the pla t es touCb ln g.
Bro ke n t e rmi n al co nn ec ti on may . al ao
'lau s e trouble. -Fred Marti n, Ind lanapoll.,
Ind.
-s
6% OllfIJ4MJ'iD ~/Il L
'0
';,
when n ickeled mcumtn x e ar e used there
Is n ot h ing mo re at trae t tv e .
Phone Receiver. Make
" Good Condenser Teat
PANEL HAS POT LID KNOBS
These mate_
WORKSHOP KINKS?
EARN A DOLLAR-
T
-
HERE are m a ny iuu e kink.
worked ou t a t b orn e tha t w ou ld
aid your t ellow R a d io work er It
he on ly knew about the m. Thu e ar.
lie", hook-u p". new "'a ,.. of mak in g
part. and various u Dlq ue waYII of operflUng eee.. that are d lltCO\-ered ever y
da y. RADIO DIG E ST i . Vfr Y mu ch Inte re llted In securln lr lIu ch m a terial.
S"nd them In with t ull derails. Indud.
Ing _tam ped en velope eo re Ject<!<1 co py
may be r et u r ned . Th e w ork must b e
entir ely original. not copied .
RADIO KINKS DEPARTM ENT,
RADlO DIGEST,
123 W e st Mad l ~on St., Chicago, HI.
o.
.,
CIIoI IoIE€TINC. T ....."
IJ l fYQ I "'4
I'IllfeJ
l oo.e, un les s so me precautio na r y me~
ure la t aken.
One method Is t o roll an4 d i p the t u be,
on w h l'lh i t Is dell ired t o w in d the eoU,
In a IIhallow d ish contaln lne holll ng par.
a mn. P roper p rlteautlons 8 ho ul d be take n
to l ea ve t he t ube In the d ish long en ough
t o have t he paralUn 1I0a k t h r o ugb the
ca r d boa r d. When t a k en out ot th e dis h
a nd allowed to dra In""" and cool , the tube
wllI har d en and' no t rouble wil l be exp er ten ced t rom s h r In k age .
~\ s imilar oper a ti o n m ay be r ep ea t ed
w h en t h e w i re i ll w ou nd o n the tub e, to
hol d It in po sltlo n . -P . J . C.
,
Making a Crystal Cup
~ -- - - - - - ~
'r:':===:::'
,
.
I
,
Finding Aerial W ave Len gth
H ere III a elm ple met hod to r rou gh ly
eeUma ting t he w s v e_len &,l h at an aeria l:
A dd t he le ng l h ot the lell d In t o the
aerial wi re I"n gtb . It mor'" than one w ir e
Is In the a er ia l, add one· thl rd of le nll:th
agaI n. To th Is add the l en g th ot the
grou nd w ire. D IVide total b y t w o, and
add the result t o the total ot the addl ·
uen.
E xample: Fl nll w a ve l ength at an a erlnl
61> t ee t lo n g , w i th lea d· l n
. ' f .eet a n d gro und 21l fee t. 65+22+12 +20
. ... J9 . D Ivided by 2. equals 59. A d ,l 119
t o 59, eq ua l ll 1711, wh ic h 18 t he a pprox im ate
WlI" e l e n~ t h of th la a nt"nna s y s t e m. Phillip Me ye re. Chica go, III .
of three w ir e !!,
T he a m ateur who l a m aking his o w n
c ""slal d ete'l tor and n~1I a eu p f or t he
Aer ial from Ford Magneto
e""atal will find tha t a thi m b le cu t o lf
H ere I.. an amat" u r kI n k wh Ich m ay Inall show n In F lliru r e t and w ith a screw
p la ce d Utrough the bottom wilt be aU that t e r e "t ""me h om e Radio b uilde r . I ha ve
hI r eq u Ired . W i t h the screw In the bot tom eonat ru<,ted a lJood aena l, o r rath er a ribbo n. by u nwi nd ing Ihe bobbins o f a d Is ·
earded magneto ta ke n from a F ord ear .
Th....... ribbon!! w er e pnU, h eod and 50 lde r ed
t oltt'thu 10 ob laln Ih e p rope r leneth. F . W . S telten.
~.
,'\
POS T
I
Distributors
FOR
DeForest Radio Sets
All Types
IMMEDIATE SHIPMENT
Head Sets
Vario-Coupler
Variometers
an d all necessary parts
for constructing your
own set.
Write for Complete Price Ust
Special Di,counts t o Dealers
r.--:~-_ I
RADIO
SUPPUES STORES
' ..... SonK.- O..fil, c.....- Pri<e4
~. dl.
DM .I. n
R~~I
TELEPHONE MAINTENANCE CO.
If
S. W ell. St .
Franklin UN
Il l:! E. nllo St.
.tasois *1.
LoR Itt t w TEL ....Co 51..
L..;;"";;.'~.~';;Mi-.
'f
FIG. ,
r,6.2
the Iw o_ln ch m a ohtne screws. T he hole
In Ihe knob Is m a de a mug ll.t f or the
IIcn w body. O n either Bide at the knob
enhu l' e thlJ!l h ole wit h a lareer d r ill point
or b It 110 that t he nu t wllJ lit In It. P a _
t h" scre w tbro ugh t he h ole , p u t on the
n u t , a nd scr e w It u p ti g h tly w ith a .. c re w ,
d r h ' er Wh ile h oldIn g the nut w it h pli ers
u ntil t h e nu t Bnd ec ee w h ead a r e embod tl utl firm l y In t o th e knob. T he n tuet r a tl on s hows t his par t of the wor k
clea rl y,
T he s w 1t'l h bl a de s a r e m ade of bra s s
str l]>s hav ing a g ood, .. U ff s pri ng t o It. If
It Is of s oft b r ass It w ill soon 10 ..... Its
spri ng a n d t here w ill not b e B good co nta c t, If b rass see m s t o be too ex pen..tve,
o r ca n n ot be r ead il y o b tain ed, open U P an
empt y tin oean and ·cu t )'o u r blades from
t h ts mat"rtal. The d ls l.. ean be c u t f r om
a p l.,., e of oa r dboa rd 110 ... t o make a suit·
a ble d i s k. Roll th is s lon l' the edge o f a
ru le, m arking It ott In to IIlJ:t" " n t h s of &lI
Ino h unti l t be ....h ole etee ue rrere nee b a .. d l.
v l ~ lonll.
Len g t he n eac h t enth m ark, a lllO
e a<.-h t1tth mar k, m a lrl ne th e t enlh marks
10 n Ker t haD the IIft hll. ," um ber th l;l tens
f r om uro U P all th e w a y around.
t he cup may be attached to the jeee o r
mounti ng board by tu mlnlt It Into the
wood. all shown in Figure 2. F or tho..... wbo
a dmire good look ing H U ll. t he thimble cup
<,an be made very altractlve.-Albe r t E .
J ones, Eas t 11l1t o n , l1a s s.
Card Clips Make D etector
Th e Illu s tratl o n en e we h o w t wo card
h old er s m a y be u....d t o hold th e cr y s tal
a nd t ho cat wh iske r . A block o r wood Is
p r oc ured a Dd t h e c li ps attach ed a s s ho w n.
Radio Bugs!
'f
Try Thi« on Your Cat',
Mi,ker
T~
/10,
IllOu
0'
Yuh, Do~41,
~ rrice
---
10
Lloten I n • • t,
l a .. marv.. l. )"ou bet,
Tllro ugll whIc h the ..... v.. com e
"bu:uln·.
AUa ch t o Ih e pho n..
Y oa ao'" " "" ilion...
And the pr oc ram Ie h .aM br a do~tll..
T .... II <lORn bear tb.. ne.....
.'1. d OZt't1 11_:- It 4&,,47.
E"~,.,.o ne .hould ha ... Ore gl" " Ikt,
B<>eanse It Ia _ hal:l47.
The famll,. . b" ,,14 • • t
G ~K"a Lla te n In Nt.
IJooe.fI ror all . " " " 0 ,,"d .. ...d ....... 1".
So mo~ all alon ..
Do- one ...... Ih. phone.
T tle ...t se nda It Ol1t to a d O%~D.
G~"II:'.
42 South Wabash Avenue
Dept. R. D.
Chicago
BRACH
W£©'ill1'ill1W
LIGHTNING
ARRESTER
Eve..,. Ii,htnl"c flu h fill. t he ai r wil b
.Iatle. .. hlch haa I" It pole alial dan c ers
to every rad io and home, " aleo. t hey ....
prot K ted by tha BRACH V.c.... m U cbl.
"In, Arr eot cr.
T hla "nfalU"c .."lI nel I. on pard day
.... d nlcbt-,l l ..orloa . uto mallully, don
not h.ve to be ...ltched and cannOI 10..
come ,",un dod.
Ra"~d • • fire lltarm .,.otema ... d. the
U. S. Anny d_d "pon tb. BRACH
An'e1ter-1.. ceea.haI l,. lUed fo:r l' ,. ........
W..it. fo.. c.. t.l oc....
Gregg Company
Preventing Tube Shri nkag e
Cardboard l ubes, used fo r tuning calls Tile CRt v..h lilker lUI well as the crysta l Is
or <'oupl<'rs, a re apl 10 "hrlnk lif t er th .. held In the c law at t he pa per cllp.-Be r l
WIre III In pla ce, l eavin g t he t u r n s ve ry Shllllng- inw.
Sold by Deal er . ElJerywhe,.
R o o m 505, 35 South D earborn S t r e et
L.S.BRACHMFG.CO.
C HIC AGO
NEWARK, N. J.
www.americanradiohistory.com
-
RADI0
lJ I G E ST
I LL
t: S T R AT E D
5
Stations Make Programs Carefully
" peak tor the R adio f ans a 8 w ell. a n d
m os t of t h.... have been Q.ulck to reeuee
t h e val ue ot Ih" o l, por tunUy and ...ger to
a va il th.. m .... t vee ot It.
A. fe w d aya alto, While t h e Am eric an
Fed" rat"'n o r La bo r waa In .........Ion. Sam uel Hornpe ra, Prulden t of t he Fed.. ratlon ,
mad. his t1rtl t speech ove r t h e Rad lophonto
a t WLW, H is talk On labor'II a ppea l 10
A m e r10a r~h ed thousan d s who, In Ihe
nat ura l co urse of " v en ts, would n.. vO'r
ha,'e come In l o c o ntac t with h i m , bUI who
tbu a had a n opport unll y to hear tb la di st1n gu la hfd man a t h is be st,
On th e "li m e eve n ing that Mr. Oompers
deU Yer"d hla Radio addreas a very ta l_
e nte d youn g C lncln lla U writer ot euudren 'a eto etee, R o ber t F. S chulkers. aU·
thor ot " !'Ie ke t a r y H a w k ln a" and " l'o1l1e.a.
M ln lt :11110," r"ad a >(lew a t o r y to hi...
juvl'"n lle audien ce and told th em how he
p lan ned Ilnd ,..ro t e his yarn~ , The eltort
br o u g ht 8 0 many compllmllnlary lei I.. " .
to t he company that a " M ll e" a lory ha ..
b een m a de II feal u re or th e rep: ula r p rogram.
Ham an In ter..' P tol'ram.J A p p ...l,
The tact that Ihe "\\'LW pro grRmll ne v e
be"D o f that particular hum an In l er l'" lIt
kind t h at a ppea l a trongl y 10 the secttcn
over which Ita w av es r adi ate ~ b"on
du e In a large m easure to the fact Ihat
M ~ , Cr n ley h lUJ called to h is a id R o bert
F , S tar man , n ta ten t ee and .'ery p ractica l
n ew llpll..... r man., w hose elt lle r h'ncea aa a
r"porte~ a.n d all. editor ha\'e trained htm
to
Station KGB
By A,
~1.
Onenheimer
RA.DIO broad c... t1ng program 18
Q.ulle lI~uarlly mu('h 11"'1 a dally
newspaper: It s erVeA ,." m ally and
snch
mUltifarious c ~ d m UJJt
p l _ th.m &11, Aa emeetat a ment tor
rtadlo listen"",, " I nee It goe.. t o 110 lJUl, ny
.. nd.. he nc e mu st come f rom as maD¥
aou re.... The da lly Radi o schedu leB ~
Jnto exurenee, schools, hO" p ltals , hom.....
oltl<:es, stores ...d co untless othe r p la cea
lin d the wllnta a nd the de"lr.." of e a.ch
mUlIt btl cat ered t o a nd cODaldered.
I t ha a been the SCr up uloua II.dheren ce to
t hlll principle, perhaps, t b a t hB!! brou ght
"" much e UCC""" to KOB,. the Tacon ...
L ed g" r Rad io b roadca~t1 ll g .at a tl o n at Ta
,'''lIla, Wa shi ng t o n . I n Ih S , three months
nr 1111 e xiste nc e , cou rruess lllo re llalo nal
and ...·o rea ot lal f'nt ed llm a um r perform_
.. r " neve s er ved It" li s t eners , who li re now
be ginnin g t o r un Into ' the t ho usa n d ..
Carer ,,1 lllten llon Is gh'en· t o e a cll Ind l.
vi du a l vrogram, each Is a nilluously
.. tlllll ed a nd w o r k ed out.
_ Of, H aa rd 1Il Portl&Jl.4
Mme.. I......" P avIo.k a. F lltnoull Sopn.no
St ran!:"e a. it rna,. eeem, KGB has never
b....n heard In P ort land , t h r o u g h some Recently M m e. I r e n e P avloska, f amed
rrellk of a t mollph" r lc a n d reographtcal
«l nd ltl o n .. nor ha vf any of the Portla.nd lIop r . no of the C hicago Gran4 Opc.ra Co m _
" Ia tlon a bNon pi cked _UP lIn T a coma. . . pany, sang a g roup ot n umbe r . for KOB,
f ar liS It baa been DOsslble to asce rtain. Fulflllin g a concert en ga gement In Tacom a. s he g raci ousl y conM Dted to singf o r t h" Radio tana prevlo ua to nee oth er
a p ptoaran ce.
•
T be j u atly no t ed Aeo lia n Q ua rt et ot
th" Kolb a nd DlII COmpa D)' ahoo ap.....arcd
a " ho rt lime a go In a .. hort COnCi"rl, a nd
loll... F r a n ces Jacoby• •·Io ll n y irtuoao with
the sam e com pany, "'all alAo t_ t ured .
Each 'We e k one or more .·audev lUe a cts
trom the Panta ges c1l'1.'ult Bp pc a r a t t he
Led ge r s tation.
T he y are obtained by
Ihe court.... y of th " lo cal m 8na ser o t t he
th eatee, who hall been qulek to gra ap the
a d.'er ll sln g va lu el! ot Ih....e Radio a p-.
pearan c" . . Among t h e bette r jcncwu ot
t hese ['a n ta g es a r llsl ll who h a vs so r v ed
t he 1.<ldge r 's lI lltene r. h a", b ee n lItlle
A n gl e Ca ppe ll , d ear to t he henrtll o f many
... vete r a n Qt t ne la t e " 'Ilr lUI "Tho Lit tle
\\' o p,"
111155 Cappell ap pua r ...l OV€
..
r or a n e Xle nde d period d u r ing the Wll.l ~"
a n en te rtahler · IL nd ,·oea ll ..t o n d eet e e lillhed a n el,,·lable r ecord.
1\
Japan••• S Ollp tr••• B ro a411a. "
J aa R....e!!. CIne.- y ....a .. V..u..I .t
Co nllld ..r a b le dl mculty flIa.a also b<"en ell._
I... rlen~ by T a coma U...t ene .... In catch ing
KOY. the s ta ti o n at St_ Martln'a Co l1e lle
"t La....,.,y, W ... hln~ o n . tor 180m .. UtU";·
I.la l peod eeaeen .
The 1.t'dcer "lIIlIon pruenLIJ t ..ro pro..rllma dall,., The atten100n pros ram on
.......k-day. run . trom t unti l 5 (Pac:lnc
Ume) and tbe e'-"nlng schedule from 1
ulltll!t. On Sundays tbe aflernoon broad.
call t is l"ngth.. n"d by an hour. running
from 3 until 5 an d Ih" e v en in g broadClUlt·
Inc hourI! a re t rom 1 ::0 to ' :30.
The V8pcr ha s 8 Radio edito r o n It.
Illarr who d" votes 811 ot hili Ume to the
prell8ratl on ot the pro grsmll and the bu t
possible p re>'entlltlon therecf,
I n ths
Ilhort time or t h.. /Otalion's ollerlltlon, thI s
""ork hllH been broulJ',"ht down t o little
..hart of n ..cl"nce and KGB pard ona b ly
l'r l<le~ l u .,1t on
It s carefu lly vre pa red,
studied l>Togram s ,
A rranI' ll St. llar P roll'1'a ma
'scm e famollR p.,rllonages have grac"d
"orne ot the L ed ger atatlo n'a broadca atll.
.
Then there 'Wa ~ also, not 100 lo n g ago,
pe tllf'l T anaka Ku m a , J ll.pa ne rse "o n glltresJJ.
a lIOpra no ot tale nt. lI er numb" r e a t KGB
IIluslr ate her " u RSl llll y , aa ahe tl ra t Illlll g
"The Last Ros e ot S umme r" In Engll.ah
a nd "0 Sole M lo" III I1a l lan.
S uch ........n kno"" n acts aa Ihe " R o y a l
Revue," an organization o f "bl g _tlmeN
a r llsls, ha.·e sl so a ppeared. Compolled ot
.... ve n artista, among them t b... .....ell·known
Doo " ly" Sl .. t ...... a n d Enro· ln RoBIt&, Hn A ·
Il ona l \·l ollnI5t. a n ex t e nded pro&"ram was
presen ted b ,. the entire compaJIY.
individual artl!1t11 o f the city a~e o t ten
dvton promlLen<:<:l. A n' o n g Ihem has been
Jan Ru _U. a youn g v lolIlIlll l ot uDu"ual
proml..... w n e ee a bili t y baa caulled q u l le
a .. tlr In mus ical ci r cles . The yonng m an.
bare ly 11, an d h is Sis t er. Ann" , only U'.
p r e sent ed a complet e program on e e ven Inll:, nmch to the e41Rcal1on ot their a ppr"elaUve aud ltor a. Child prod lg l..II, wi t h
w hich T a comn a bounda, a re t r e q uen t
broadca>lUng at>«"lf.
T a com a hl fast becomlnlt a Radio 10wn.
R ud lo haa taken Ihe c it y by sto r m and a ll
yet t h er e Is n o s ign ot a aln.cke n lng In t h e
In l l'" r e.. t or e n t huala am, The -number or
Il al enera la g rowlnll" d nlly an d KOB III
alive to Its re sl>onILlbllltlel" t o t he "e hun·
dreds nn d Is en de a vo ri n g to f ulfill them
In mo "t credllable m anner In II " l>ow e r.
_---- - -
Station WLW
By H arry Pence
I T H O L, . Im po r tl nl!: celebrities of
na tional r e p ut a tio n t o r ou la land In g ..dra ... l ng card"." the Croale y
).lanuta ct u r ln :( CompanY--4,>perati ng broadcas ting "lallon W LW, of C incin nati, Ohio
_haa s i\"en the Radio public a _l1es of
.. ntertalnmenla t h a t have bee n tar above
t he ordlnar)" In a r tlattc merit. all w " n aa
much m o r e tn t " restl n g to audlencu than
the m ere ambitloull proa;--ra m ll oltered by
some of Ihe more wi d el y known sta tlon.s.
From the RrBt tbe ownera or ...' ·LW,
kno.....l nl: th.. mu sical ",,,ource s of c teetnnall , reaJl aed t h IL l It w o u ld seldom be n eeC""llry 10 gO far for pe rtor mers ot the
.· e r y hi ghest e xce llence, .. no t hou gh /lOm e
dllftcu lty Wll8 ell>pcrle nce d In overcom ing
the vrejudlce or some of the more t e mpe ramen t a l muetc tane, t he Crost ey Co m pany " ucc"c d ed In e nab lin g R a d io t ana
w it hin t h e r a n ge of It ot Ma Uo n 10 usten
t o rnn n y o f t he m llllt ..r I.er t o r m e r s o n the
t ea ch ln!:" flta ",,, ot tho C ln.. l nnall mu si cal
Instit u tion" lln d t h e lr mo r e proll cl ent pup ll s .
..taUOIl s. ....... in Other W IIP.
~or h a s ,' n i ortll lnm .. nt alon" be l'n the
obj ee t ot I"atlo n WLW , Wh ..n t h e Com·
m un lt y Che"t cllm l,a l.:-n threate ned 10 ta l·
ter a bit th .. team Icadel'S or t he d ri ve
....e ,..., In v i t ed to ee nd thei r 6peake rs t o
WL'n' an d v ut t heI r ro u _ ges and a ppeals
Into the a Ir ,
Th... head fl o f the va r lou.s city d e part_
menta ",'e re .1I In vited IIO me time agO 1.0
a d d r e_ t h" pu bllc hy Radio. giv ing a n y
m e lUl& ge conce r ni ng the .....orklngs ot t he ir
departme n l " w h ((,h t hey t..1t might be ot
public Int""l'(OfII. A number of t he m re"pon ded a nd tol d the public how t he at·
fa l .... ot the c it y f!OlIld be the beu""r adm in istered ..... he n t he e nd ....-era o f official.
\VerB u nderal(lOd and a CO*OP<lratlon .. t.
t« ted.. It on ly to tbe exeee t ot , mu tu a l
conRden ce.
Th e b rl e t d lllCU8fllon o f I"e commlsa lo n.
e r ot health Willi an ~ n t er l a l n l llG" and Ins l rucllve lal k. prod uctive o r m uch beneRt
In t ha t It !:"ave hla h.,arers a clea re r ldl'a
Ihan Ih "y ha d p r e vl ou.. ly tt.1.d ot t he cons t r uc tive w o r k ot hi s departm ent a nd the
ends Wh ic h htl h o pe d t o ec nte ve for the
gene r a l wel fa re .
CO:Il:'I'ent1o ll S pe ak.rs Alao B r oa 4ea at.
F ew opport u nlt lc" In t h l.. line h ave beon
o\"Crloek ed Ill' >l l a tl o n 'VL'V. A s na tional
trade, ln d ll" tr llli and I' ro t osa lo na l a SHo c la_
Il o na met here In natlolla l convention
t h e ir lead lnlf " veak.. rs h llve b een Invited
W
ii
I
T.-ka Ku.....
Japan""",
So"r.tr_
to a Qu ick appreciation ot t h e opport':'nl:
tlea t hat eltl st aU a ro und Bnd a prompt
a c tion t ha t haa. Ume and again. ~abl.-d
him to obl.&ln the ser\'1ces of pr omlnenl
persoDages In ord.. r to give the public aU'"
o p portu n U,. to lI"ar the m at the ti me
wh..n Int"reI't In them alld the ir w o rk W"U
at ItII heig h t .
"StaUeN H ldom m a rs a W'LW program,
e ven In _lIu ltr y ....eath er-but t he n It la n ot
the pre sen t pUlp<»le 10 d lscu. . t echnical
atral ",. On e who deilired 10 d o 110 coll id
tl nd m u ch to In teres l hi m at a ta tlo n st
No r th "lde, Cincin na ti, but f o r thl' present th e eltort Is made to show ....hy the
WLW illa ti o n Is popular,
If th e pa rticu lar po li cy ot good progr a m m aklnl' obt alna th si def'l red r ellult , there Is an oil_
v leu" ..x planatlon,
At no s t a g e In the devclopm..n t of a
v c r y e ucce s s fu l ente rprt .... hall a t a tl Qn
"\VL W talte r ed In Its pollc )" ef Kh' InK
nadlo ran ll t he ir regula r ''''e llin g' s en,t e rm lnment malnta ln ..d at Ihe hlghe"t
..tanda rd .
6
DUTCH AIRPHONE
Book Reviews
SYSTEM TO GROW
I
L-.
RADIO TO AID IN FIGHT
AGAINST BOOTLEGGERS
I
RADIO MAILING LIST
~ ::~~ f~~~~.~. ~ : : : :';:::
5~f
New York P olice to Install Ai,phone on Boats
PLAN TO INSTALL PHONE
FOR FARMER'S USE
NE'V Y ORK. -The poli ce department o f
:s'ew Yor k hav" in liialled Rad io o u tfits
to keep In tou ch with pollee boatll u aed to
Trans mitt er of Efficien t Design Is U sed
_ Ran ge from Ams terdam
t o Li verpool
C omlm mlea Uo n I.. al llO ma in tained With
other pol k " . t a Uo oR, T h e pollee departmen t a lso ke e p" a
watch In ord er
Radko )I... "f.<!ta~ f or 11_( ..•
and a D)' OCbu liIIt 70a ...... t.
1~
Trade Circular Addresslnt; Co.
166
w. ,\
!k r .....
P
Ch l.... a . IlL
'RAN KLIN 1111
prev e n t s muggling and bootleggin g.
e<;I".t.,,(
t hat they ma y be In & po s ition to rend er
any a . IIlatance po ellibl e In re s pon se to
cal ls
fNII<'dGl ,,, R.l DIO DIG £ S n
A ).ISTERDA31.-The Governm.... t of the
;so"'l h e rland ll III n OW broadClUltln(l' weather
reporu by Radio telegra ph tw ice da lly, b ut
Is plan.nl.llg t be In stallation o f Rad iophon e
Bervtee 10 order tbat fa rmers w ho do oot
know code can newe In.
Every nftet'n m tnute a the Am aterdam
Btock E x chan ge ec e ue ou t b ulletin s by
mll.n ll o f w lre lell8 telephony. g iv ing the
ru ling Q.uota tl o ns of lhe excl,a nge. ,Vhcn
t ho excha n ge I. e tcee a , a p re s e bureau
m a k M use of the broadcaetln g s ,.e te m tOt
t he dlstrlbutl on o f d ome s tic and f oreign
n e w s , as ...e ll &II fo r eign e s chan ge and
Bt ock quotatloos l.II code.
Qn:::helltral mu s ie a nd s peeches a re broad·
e-ted S uodays fro m 2 t o 5 p. m. b y the
N sth er la.nd ll Radio lod Ulltry a t the I laWUe..
W ith a radlu ll of a bou t COG mile.. this
Company's en urt.lnment hi said to bave
becom e very popular In the BrIU.~ retee,
D."'. 1op J: fIIcl_ t 'rrU>8m1ttft'
Experiment s w ith oql y .25 amperes In
t h e ae rial and 160 w att- In p u t hav e ca....
rled b r oa de1Ult ll of both m uSic and speeches
a s t a r as L i verpool . nd EdInb urgh euccelllltuU y . T h e t r a lls ml s s lo n ot matte r
w ith this email amou n t of energy 18 said
t o be t h e r ee ult of an In ve n tion of a n elec.
t r lcal en gineer named. I d _rd.. pres id en t o f
the Industry. who h.a app lied lor U . S .
pat e n t&. T h e Company Is conduc tin g par t
of Ita correspon4enee with Ita customers
b y & 410.
T he lIareonJ WlnoleBS T el e p 'ph Comp&JI.:r' s nee.nt testa of combined Rad.io an.d
w i ... communication betweel> members of
th" Englis h A.ltgio-Bata.. l.aD Soclely speak.
In g IrolD the J,larconl Housoe In Lon don .
an d memberll 01 t he N ether...... d . E n g land
Socie t y at A m sterdam. llpeakl ng t r o m tho
Bt OCk Broke ra Society, m a y Tellult In th e
6lltabll llhment of s combination w Ir e lin d
n a d lo . yMe m con ne ctin g t h e two cc un t r ies .
"ALL-AMERICAN"
Amplifying Transformers
Two ,._
oL .'..'
t"l .... ILII O"lIr tb e
,",orld p
nt_
~
a nllnt _Uar.etlon.
Radio elld Audio Frtoq".n e,. .
l END rD A CIAcU LAAI
RAULAND MANUFACTURING
n ....th
D.M1tonI S _ t
co.
CHICAGO
Photos, Diagrams and
ARMSTRONG'S o Graphs
from Two
New Super-Regenerative
Diff erent Sets Constructed by. the Author
RECEIVER
By KENNETI-I HAR KNESS
Booklet Ready ror [)"'liver)'. Price 40e
How to constructond operate it
PUBLI SH ED BY
m:br l\abio
~uiIb,
line.
236 W. 34t h St•• N ew Y ork Ci t", N. Y.
CROSLEY RADIO APP ARATUS
BEITER-COSTS LESS
Cro. ley Two
Ste p
A m plifie r
Radio License F ee Law
Considered by Chicago
Department Store Buyers
to Test Radio Apparatus
C H ICAGO.-An ordinAnce .....' lulrln'l" the
In uance o f perm Us btofo..... t he In.. ta lla tl o n
01 a Radio ee t of any cha rac te r and In cene ral re..atln g such In .lalla tlon " In Ih e
sa m e maDne r that elfftrical wlrln .. In_
s tal lation s are t realed ha s been Inl roduced
In t o t he Cit ,. ccuncn In Chicago.
An In spection t~ of
for r .......h·lng et a uene only a nd U f or l"Ombln ed t ran smit·
tlng a nd r ece ivin g statlona '1"'11I he c h n r$l"..d ,
R e· IM Pcctl on s wm b o c harged for at U.5Q
per h our, wi th n o e neree loss than 11 .50 .
I ns t all a ti o n r e qul r c m cn tll are made to r
r ece iv i ng etauene on l}·. a nd to r combIned
u no_ml t tl ng an" ",c('lvlng stations. Wh ~n
It Is nece lls a ry to dO any wiring t o take
pow er trom street m ains. the ord inance
pro\"ldes that Ih e w ork: can be d on e by 11cen _cd elect ricians on l,.. Eetlmatea of a
yea;rly revenue of II QQ.OQQ have too,en
placed o n the Ilcenae f ea tu res <I f the proposed ordinance. Penallles <II from f ~
to U QQ l or each v lo1atlon of It are proVided,. and each daT's u ee l s con lltl tu ted a
separa te vlolatlon.
E xami nation O utline Su ggested to
Insure Q uality of Sets
sa
~·A SHJ~OTON.- F:v or·lnc rea..lng pub lic
Interest tn Rad io h.... a dded to t he t ro u bles
of department e rore bU)'e rll an d <llher..
h a n d ll n Jl" s uch eq u l Pmcn t.
B e cau se ot
t ho r ll t h er t C," ('h n lcl\ \ pr <lb le m " Illvolved,
aClual and proapec th'e sajesm en ct "ether
wav e" recel vlnlf de vl cc s say the y are UP
against It In Ih elr efforts to satldy th e
trade. F1ndln&" no Informlltlon avaUa ble
to use 111 8electinC good o r rejecting b a d
appara.tus and t earin g t b e 1011II o f ell-tabU ah ed Cood ",11I. appeal.. h a .. e been
dlreeted t o t be Bu reau of S t andard. o f t he
Department ot Com m erce t o de,..1IIe eland·
a rd te.tw g m eth ods .
1'.. rforman ce teet m et hods l or Im medlat e a .... by a. eonu nerclal t es t lnlf Ia.bo rat o r y
were r f'Cen tl y a gr eed n pon In an o u tline
b7 repr....e n t a tl v.. !1 ot t he Bu r eau ot Sl a nd.
ard .., t he Ele ct r i ca l T e etlng labo r a t ories of
New York. an d th e N ational R etail Dry
OOOOll A s socl allo n . SUggcstion s r egard ing
I m l' r o Ve m e n t ll on t h es e me thod s , or new
ms thods lor t .... tlng the e'lu l pmeu t eu bm lt t ed by the N aU o lla1 Re t ail Dry G oods
AftUCla tlon will be lIu bject to appro val
ot th e Bureau of Stan dar<'l e.
The t ellts ou tl In ed Include tII:aml na ti on
a s to the mIl\.('rlsls a Dd worlt man s hlp of
eoa etrec t ten, the m ..c hanlca1. &lid electrical
d _ Ig n. .impllclty of adJWllme:n t. TUCg ed.·
ne.... senll ltl vity. a harpn..... 01 tuning.
wave length nDC'1!lo and falthfuln NII of
reproduction In R adiO t d e pbol>l!l receptl o n.
Boys'
lan Canoe
N
O R T H Camp
P ORT. P
ME._A
large Radio
Pllrty ot
b o ys f r o m Cam p Navajo. a . .It water
camp for boy.. 011 tile ehore 01 P enobscot
nay. wlll IItart sho r tly on a ZOO· m lle ca noe
tri p along tbe In w nll w a te rs and up II<Ime
o f the rivers tlowln g Into P enob llCot Bay.
The7 ....Ill k eep In t ouc h w ith the camp
b7 Radio and will have ea noea equipped
for thlll punooae. T h o.... 0 1 the boye wbo
are not " 'Orsed In the art of rec:e 1'l'1ng are
no", bein g tau g ht how t o IIOt up and use
Ul.e a~tn ..
m E'din l aid.
fo r h el p o r
on.. ' JA n KO gESIOR ..... offoftl"flO<l ~ It¢Pl.1 u."
_""
.. """ ',,",,",1. . -, ...-.101
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ha-.t
nc . r""
~<>fr""" 1 lo(l~_ r
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tn ..
'leCI"_ .
brI
,.. tn DO tho
"'
,
tou. "'oU""., .0<110 tol . l>ln",.. 0"" """"""n'lo]
.
II"" • • ".,...,1". up to .. ,d t"e " ........ 8011 tn.to...
8bll>ll ..... "tlU""" 00 tM AU. " U"
1>_ _It..'"
Col....rt
_ 0'
"",,*,01 t l> Clb<tm,. I~ " ILoilo lalrJ,>bo.... "''''''''
",1
..... "'. ".,. :<1...... 11, N • • 1 •....,. .Itd on
;ti _
l ...,
In
to> 1·1O. . - u. 1 _..
0l1<'aco
..u... _ .. &to
.,.,p od la
CII ." "
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.-tltlOllo. I' 1&
TbIlO
,... Iloo
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fw _a _ _ u.
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of
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1'04...-..0• •
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CBO!lLIn" O W D COloo"DJ.;.....llIUt
_ ......& '"to,_
_ '_
- - _r ..
_ _
11.....10
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no. IIARIO:O
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11.II....... ... ~ , . . . . _a1
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B. UI.... " 4 "
wtUI _ l<...-...,
P R ICE
StO.OI
'nIf H4 R KO S ENIOR
II> ............._
.tlb UN 1.0-""'0 . ..pH ft.,. d ""'tl""l . _
.
Can adian H otel I nsta lls Set
A r ecei ving etatto n hall b een calallllHhed
In th e G r llnd Centr al 1I 0 t.. l. Sl. Cn t h ..rlne8.
On t a ri o, whic h cllli ms t o be t he lir_t hotel
In Canada to s upply Radi o musIc to tbelr
gu .. s t8 In p la ce of th e old· tas hloned or.
cheauL
c....
~
n :. w.4Y
n. .
CRU ll.l.J:Y VAAl.
PLUG hkea TWO
h ead _u a t sa me Urn e: l akes AU i1Ype:a
01 eonII Up . ermJ...... PrIce 11 .10 eae b.
It T...... 1-.. 10 t:.....10 ' 0 ~ L1wb'. OW,H. u.
\ ~==============~ "
H ead q"arl en for
Radio
Supplies
---
aad Equipmellt
Gives Movie's Place to Radio
Badle Do-partmnl'
P O RT A R THUR. CAX._At a llellslon ot
the convenl!., n ot tbe xaUon,,1 Cou nCil 01
,",'o m~.n . h e ld he r e rec~n tly. o ne at t he
m em ber. e u ggellt ed t ha t H.ull o w ou ld o us t
m o v lee trom ttie rr Jjopul a r p ll<ce In an.
o ther sb: mODtu.
E~~.s
72 Well Adams Street
Chl~S llO.
l"JU CY..M : }to<!<ol A. 'I.U: ;\Isdf"l B . , U 6 ; )l o>deI c.
Fer KDnb .<><1 D1&1. 40e U.ne
I N ado1ll.1o..
10 I'"
11 DO .
I/."D1ben.. ta•• ~ Cnatal
eomblAed r" ......D.1f l1Ie aartto
'16.00. y Itn>4.. c!nlr . 0..0161"1
...... Iu..
pn>4uc1,,&" t......r........ ... "arIomel..... ".no-uPt...... "',,01-._1<ID.1I:
d sn...... _ k ..ttI. eab1_ U. r h- Ul .. ' a p • • lteh_
tapa. blndlD.1I _Illo .nd DI.D.,. oth ..r
arltel . ttae<t lD. radiO autllt&.
tb. C
Fr""t_...,.
w . a lllo .....
R_I"u No. 1 e lld
8eD.ioJ". ()qr R.dio
....
prod_
....
Ie
r..u
~p
"7' Doteel.... Valt. tb. 1_
Tunoed Ampl1ller. eoatJ "&"
8F_'"D FOR O fTa
C .4.T A LOf;
CROSLEY MANUFACTURING COMPANY
0 1.
www.americanradiohistory.com
CINCINNATI. OHIO
R ADI O D IGES T
ILLU STR A TED
7
,T he Radiophonist's Mart
liE EXPE RIME.'-"T AL Blase In Rad io
tlu pa..Ae4 and tbe dtscernl n " public
III n o w d e mandl n Jr e quipme nt e&pabkl
of mo re &eellra t e reproduction of eetce
. " d muaIc. azul lbe
ellml~Uon of
que nc,. I. not Il mlted In Its ap plica ti o n
b,. dlahlrblng tube a nd ba ttery nolsea.
This I. bet-auae reeee n ol sell a ... u au a lly
a t a r e la tl ve l,. slo w rate a nd a re n o t eff ecUve l,. transmi tted t hro ull:b a n a m pll tier d .... lgned for Rawo fre-qu ..ll.cy currenta.
Tbu . It Is pDfJlllble to u se many .tagy o f
Radio f r eq ue nc y a m pli tl ca tlo n. wne ....a.
a ud i o fr"'luen c,. III u lluall,. Um lt ed to t _
o r t h ree lltages at mOllt..
M icrodenser Has Vernier Adjustment
a n dt ..
t o r li OD an d und elli rahl e noises. To o btam
th_
....ul U It ill neee......ry t hat t h e co;md _ r. One of tho vital parls (If the re-
«h·l n.. ee t, ha ve ...Ide r n0l:e. greater
Nlleetl l' lt ,. and pennanent adju Btment.
T h ro uCb 10lle and el<.bau lltlve . I u d,. of
tbeM proble m" ocm pleod with countlee. 11:11:_
perlmenl.. a De.... t y pe of v e rn ie r eonde naer t h at prod uce.. the pe d<!'et r'elIulta
d _ lred hIu been de\'eJoped.
The ml c rodenser . all It te kuQ,,·n . III
hv.1lt with b u t two eu rfe cea, the pe c uliar
aha pl ng o f whI ch mak.... polJSlble greale r
HF. CROSLEY " a rlable conden ller Is
o ne of the Im 1>r o ve m e n t Ol In na dlo
a p p.o.r .. tua Intr oduced durin!: the pa llt
f ew }·" a r " . It ha s a n umber of Rl1vantage"
over the type of Interlocking p late a ir con_
denser.. It dependll u pon a t hin s hee t of
m lea for Insu latlon b etw .,..n the 1>latll•.
As t h ere III no friction fro m th e o1><'n ln l\"
a n d clolll nl':" o r t he plate.... t h" m ica w ill
l a llt a " long a " t he con d ens cr , Morc over,
the mica will .. tan d u p u nd er mu ch h l gh ~r
vct tage tl nm tho a ,' erage a i r condense>'.
T
ca~c1ty In II. very an U\1I Il p llel! , The a ccuracy ,.,'Itb whIch th e m icrod ..n ...... r ca n
be adj ullt e4 en abree t he o pe r a t or l u t un e
out tmdeslrlLb le nct ee e a nd " Ig nal. here tofore lmpu8" lble t o eneanare . D ue to
greal l'r r>ln!:e Rnd nn er all-Ju st rn ent It Is
1>08f1lble to Ulle tbhl In "trument for 'Var io us
.clrcu JU and l' ur po8es . m alj:(ng It espec iall y
valuabl e to the experl m entllr.
Th e rat.-d. capacity ot thc new d es ll>n
,"ern l.. r vs rl able cond e mler Is .00 1 mic rofarad. Due to It s Ingen lou8 l"ethud of
adj u8 tment 11 runc ueee as I!!ticlently o n
a U eu-eune roq ulrln g SIIY capacity up
t o Ita Do r m al rating.
'Vhen used. In a
vertical positi on t he base anay be nlled
yUh 011 t hen-by Increa8ln~ Ita capacity
H V"f'&J Ume...
I
InlFor
bet...een
d ialtmen
andt, ca
ClUe
o .....
t~
co ursethe
SdJus
'amlev
er ex
t end_
ltig tl\rough all arc o f ~y de ~eea I.s
pro"lded. Th ill le ver e xplol?s Ule ea ure
nn l e of the mlcTOdetll... r · ''MY q u iCk ly
f rom m a xi m u m to Ql.lalmu m . T he fi ner ce
n 'tlI le r adju stmen t for h l nlng Ls m a de by
t urn in g the knob In the ceD~ e r t hrout: b
a n a n: of 180 d"grees. Thla a"Justm"n
is po _ lh le a t
pot'IltI..." · o f , t he cam
,===~::::::::::::::::::~~=~:::~~:::::::~=
an,.
te vee.
T h" mlc rodens er Is suitable fo r etlh"r
U b le or pa nel mounting. F OB panel mou nt-
Inll" a % tnch hete b all that U!' r eq u ired .
It I.. but 2% In ches In diamete r a nd ext, nd s 2% Inc hell ha ck from t h e panel. T he
dial I" =~ Inc hN! In d iameter. coa ted with
bla ck lIatin tlnl!'h w ith raised envee ma rk
logll.
HROUG H cxhaUH Uve researc h ove r a
p<'r l ol1 of m lln y months, CUlmlna tln it
In th e p.. erecuon of t h e R rla Ral1 lo
freq uen cy t ra Ollf o r m er , many of the d Uftcu l tl ea ("nco un tered unti l now tn Rad io
Ireq ue nc y ampUncaUon h a ve bee n ove r«>me, r0.<!8u lt .. o btaln" d ... Ith thlll t1"8n,,fotmf!r and domt'8 tlc Va CUUm tu be a nave
I' ro \' ~ equal a nd In Sl>me In sta.nc" s OIU_
""rlor to the ben th at Europe h a ll been
a b le to pf'Oduce. u"ln g vacuum t Ubea of
" p"cla l d UI.#n.
~u cce_ ... u
a.-.ure<i b y the .,.ital d is ·
('O""ry that th e etncien cy o f Radio fO'flu ency a m plUh:aUon la di r ectl,. de pe ndent
u po n Ib e aeC"Ut'acy ... lt h w h lc b the tn.n..
f ormf'r III t un ed to the Incoming O5dUa.
tlon . ThroulI"h accurate tuni n g o f t he
t ....nll form('r. tb e e trect of tube c.pac lanee bas been n e utnll-.1.
A b o by reo
d uclnll" the roapacltallce etiect of t h e t ran. ·
f or me r It n l t . ·. co n!lld erabie st,, ~up r atio
hall bHn prov ided. red ucing the n u m ber of
nage. r eq uIr ed.
T
Trlll' sforme r
Insene.! II'
Vacuum T u be
.s ocke t
Con necti.,
fo
Primary
&Seeonda~
Tr lll"sjOfme r
In Po s it iol'\
forf-- - --.>III
e"se Ho.",tin&
ErlIo Radio Freq.....cy TTallsf_
T he etftdeliCY of t h is t rans former Ia
lIuch as to r eq u ire a lI~e less of am pll tlcatlon t han la nt'eded wit h a ve r Ail'e tran ,,·
f or m,,",. Llke ... l"e. there Is a marked
Impl"<l\"em e nt In cI"srnell8 a nd d etl nitlon of
. I~a ls, w ith a minimum of In terfere nce.
Th""e Rad Io f re<luency transforme...
" mploy n O Ir o n In t he i r magnetlo circu it .
a"oldl n!l"
the
Inevitable
t ran sform.. r
IOlUlCa w here Iron Is pr l!.\le n t. A t the .....me
lime. d ue t o t b e s pecia l conatrucllo n. a
wide band o f w ave leng tha la cove rel1
from no to 6lHJ meter s. ",,"om o ne e!Ctreme
of wave len~ th to the oth er. t he e lflcl" ncy
of the tra n8fo r me r varies but slI.,; ht l,.,
t hou g h m ll llimum r esults Ilre obt a ined
00 a wave l(OnJ;: lh of 360 meter..., for w hich
It Willi ellpecl a lly dllal l':ned. to meet till!
lI"eJIer a l d"n,a n d r esll1 t 1D.g [ r o m the em_
ploym eDt of this partle ul .... _ve l"nglb
10 broadcast ing.
I n mult l -e tage a m pll tlel'1l, a dl tre"",t
tra n s f o rmer Is u sed tQ ~h eta.ge , AocOu n t Is take n not onl ,. of the Inco m lll.g
oscillat ion, but a lso of t be I..-d t hat Is r elIec t"d back to the grid cln.n> 1t of t he eucceed lll g "tage from the p la t e circui t. ...
a result o f t he tube's I"r ld p""te ca pac ity.
'xhu" . by COrJ"la tln l" eac h lraDllfor m"r
t o the load In t h e pla te circuit o f tbe
a uc ceedlng a t age. super amp lilteaUo n III
o btai ned.
Anothcr ad,"sntage o f t he E rla , t rans .
f o r m er 18 that it doc I:I not e llhlblt the raI""n e r a tl vc properties I ha t a r O c ommon
to mnny Raul o f r eq ue nc y am p lt'l'ler .. a ll a
r "lI ult of Inh oren t cal,a cl t a nc e coupli ng
he tween IItag"...
By h O\l Hh' K t he t rlln efor mc r In a sh e ll o f hell VY btll " " . the
coupll o g capacitances bet wcen eta ~cs are
m ln lm lxed and re ~cne ra ll\'e c lt ee ts are
a vo ided.
The dcs l gn of the transformer Is s uc b
t hAt It can be e..
mounf ed c lther o n a
tahle or panel, or ""t tnto any "tandard
v acu um t u be socket "'lUI d lllgonalllprlngOl.
T he latter feature will recomme nd 1t "" lf
beea..... of the t'Xt.Nlme l1ex lbl1lty of
boo k _u p tha t It make8 poSlJibte. as w ell as
becau8tl! of t he a eatneA of arrancemen t
t hat reeulta.
For amplltyln t:. u l'llnt: Ule E rla t.ran eformer. any " tandard rou . o f ampl Uler
t ube may be u sed. AD ampllf,.l ng tube
rn a ,. s lso be aatllJfaetorlly employed as
d e t eclor . h y apDlTi n C full volta lie to Ule
p late e trcu lt of the tubt' o neet r l!.\lults,
ho",·ever. a re obtained w i th a ltadlo t r oD!DO detecto r t u bt' o o r Ita eq ul\·ale n t. Ullin I!'
a r ed uce d current at 18-n v oltll, T rylnl.l:
varloua voltages wil l quickl y de t ermine
t h e bl'flt voltage to U IM!!.
Th e d e,·e lopm.m t and pufectlan o f Ra·
diD f r eq u en cy a mp llft catlon ma rk a t h e
g rea t""'t a dvance In the s e l"nce of Rad io
Ihat ha .. t a ken p lnce etnce the In ve ntlo n
of t h" thr" ...el ec trod" v a cuum t ub e, S Ill"n al s t ha t are t oo weak to bt' de t.. cted by
"II,.
ordinary m e an " a re r ea d il y h eard ,.IUI
Radio f rNluency. t h e a ddl tl o n ot e \'eD a
81ngle staKe re..u ltlng In an asto nish Ing
Improvement. N Qt only is there a trem endou. Increallf! In the dh' tance over
wh ic h . lll:na lll are hea r d, h u t t he r eception of 'Vol~ and mUal c Is u ncom monly
clea r and Ir", from dlst ortlon. w ith a
marked ab" ellCll o f t u b.e a nd b a tt" ry
noises, I n add itio n. n l eetlv lty Is grcatly
Increased. a va riation In w a ve l en g t h of
only t w e n t y. n ve me ter" between a" nd ln g
atatlon .. be ing lIu nicl e n t to bri ng In t h"
o n e station to t he ecm p je te exclusio n of
the o th er . w ith e mele nt tuning.
A nnal and hi ghly Importa nt a d"antAgll
of Rad io freq u cn cy amplification Is t ha t
i t make s th o u"e o f I h .. com pact and COli·
, 'en lent loop ae ria l cn Urely prac llcal.
cept f o r e x tre me lon g range r eceoueo.
For l oca l r ec e p ti o n . one l!l lage of nad Ia
freq u ency a nd a 1001> w lll b e fo und e nurel y 8I\tlafactory. und" r n o rma l cond ltl o ll '"
B esides Its con v c n le n~. the com bl natla n
of Radio frequency a nd 1001' hall ad n ·
tage of gTea t" r se lectivity . d ue to dlr tiona) pro pcrll... of th e la tte r . AI " o It
e ll m lnat ell Interfe re nee r esul ting f ro m
etaue d ls t urho.n ceB t o a r emarka hl" ee-
, 1<.
.....
T h e reason for t h e . u pe rlo r teIIu l ts o btained with Rad io fuq ue ""y a mpllftca·
HOD Is tha t It enabl"s \h e d.. t ect oe t ube
to d o It II w o r k m o re emcleoO,.. .A.. b w t' ll
kno... Ja. .. d etecto r tu be will f an to respo nd
to les s t han .. g i ve n IIlgnal vol talt'".
Through tt>" correc t com b i nati on of a mplify lnc t u b
and R adio frequ" ncy t tan9forme .....
f bl e
s ignal
,"o ltages .....
brought np until they are a ble t o o pe t e
t h e d ct ec t o r t ube In a IJR tlsfact ory man·
ner o
X o r dOt!lI It m ake a n y d iff erence how
""uk th e In co m ln r,r "Igna l 18 to s tart .
Pro l' er R a di o am p li fica tio n ... Ill brin g It
up to Bume l" n t IItr ength t o n ,ake the d et ec tor ope r ate . afte r which a udi o a m l. lItlClltlon m a y be h rou ght to play,
U n ll ke a udio a m p ll flc a tl o n . Had lo fre-
F.F Charg~r Stops Battery Worries
,.dthoul pnncturlnl;. b r ('ak ln g or . h o....erIng. T here rore the condense r can be utoed
.... f .. ly for C. 'W. work or modulated C. W .
work. Anyone w ho nas exper lmenled wit h
Itndl o phon y w ill rea d ily rtlco gnl ~ the "d _
\'"ntal;e of t hi s f ca t u r e.
F.ach ecnc eeee r III carefu ly \ ostc<l to
w lt l".tlIn<1 one t hou s a nd vo U a, An o tllc r
d ec hl cd ..dvan lage of t he conseneer Is thl'
f a c t t h at t b ..r e Is no dan~c r o f shor t ctr c u ll ing lhrvu gh !>ending of plate•.
Y il:R Y RA D IO fall d reads t he tl me
"'h en his "A " battery requ ire" rec harg ing. Th is m l' an S a mee Job of
haull nK " 'bat .......ms to be a ton weIc ht
10 a baHe,.,. IIt a tio n with.....rha l.s. thl'
a n u r ln l\' lIroapect o f spllllnc 110m" of th ..
"I"clrol)' l" o n the f ..... Uy carpet or. berter
s tl ll . eve r a brand -new . g lt.. All t he
lloa p an d ..... t er In the w o rld wllt not replace the materia l that the acid has Icft
Its mark o n.
W h a t tb" D Is mc ee entlclnlf than lba
prospeet of charglgg you r . o wn halterle"
d irec t .f r o m the e l<!Ctrlc light circu it f tt
can occall ionall,. be d on e w ithout "veetal
a p par a t u s, b ut It req llir es a knowledll"e of
elect r ica l er re uus, and 8tor~.. hatte r ,.
cha rging that u-e amate ur lackll,
An
attt'm pt a t r echar ging witho u t th e ap·
paratus u " ually re8ults in blown (U""II
" n ,1 a ru l n" d ha tte ry ,
One ot the b attery ch arg..... o n the
m ark et. m anu fac tu red by th e France M f ll" ,
Comvan y. Ill: Uluatrated On (hili 'lillie,
Thl " r ecLl tl..r ami char glnlt un it cun I",
U>!l'd On bot h " A " an d "n" 8tm'a!;"e halt"r l..... The re are no part ll to ",..ar OUI
a nd It r CQu l r c ll Il ttlc attention, The rac e
that It 18 por tab le makes It a ha mh' Rece .." o ry for the Ha d i o amat e ur. It III ex·
ccedlllK I}' l10Jxlhl c ,," to \'olla <;e lind c" r rcnt rlln g e. T he actual cur re n t drawn
f r o m th oJ h o u s e Il g h tln ll" circuit amou n t~
t o "lI ry lit tl e. the re f ore maklns recharg·
In g a n Inex pemd\"e o p<'M1l1on, Datterlcs
ca n 1.01' s e t up and r ..cha r ged ov er nig ht.
Th e ol "'ratlon of the F -F macne tle teetl n.. r dOC'B not depend tn a n y ",'sy upon
t he co ndi tio n o r !!,tate of cha rge In the bat·
te r ,.. hence in m any casea a bad ly a u 11>bIIted or d ead battery m ay be brought
back to uBe fu ln.... a If there ,,, an ,. chane..
what .. ver.
T o c b arge a 6-"olt lIt o ra ge MAN battery.
the ..... lI ch III t hm,,"" to the right a nd t h t n
Ule _Itl"" c harltlng w ir e wit h .....t cll l'
Is eon n..eted t o the po"IU ve termina l of
tht' battery. The other cliD I.. conn ected
to t he ne gative tennlnal of the batt"ry.
To c harge a storage .. ~ battery. which
ma,. co n. l.. t of any number of ~ II. up to
nft y, e qu I"alt'n t to 100 v olts , the !SWItch
III t hrow n to the left Bide a a d the _lttvt'
c ha r ll" lng ", Ire ",lth r ed clip III connuc te d
t o the positive te rminal of the bRtll'r,. ,
The ol h"r clip III connected to thc neg"th'e
t er m in a l of battery.
Th e am mete r on t he r eclltl"r r ca<t"
dir ec tl y In ampere:<. and will t he re forc
o n ly " how a "light mov tlme nt It'h .,,, charI' _
In ll" a " n" b.alte~y. n ue to t he " m il l! curr ..nt nllwl n !:", hut the g low o f th .. la m l'
will Ind l('ate Ihal the battery la 1.o0l'1 u II"
l·hflrg ed.
E"'I
8
R AD I O
U I G E ST ILL U S T RAT EU
CONTENTS AND HOW
BEST TO USET n }>:
8 T ATIO :S seh edules, gt,.('u
below, a re lis ted alphabetically
by tall letters,
Following the
fall i . giVt D t he eity and etate,
t ile wa ve lengt h (P RO\"IDIX G a
\1'8 \'0 h' ng t h oili er th an 360 met.l',~ ia u~{'d ) . t he mileR r ang e of tho
fltillion, th e owne r of th e st ation, t he
se hed ule ot op r lll ting hours, and the
kind of lim o used.
The s t a l l', ci ty a nd t all Jill! g iven
followin g th e s ta tio n aehedule Jillt Is
merely aD index. One wi shing t il find
t he calls of tho atat lona i n hi s v icinity,
will find this llldu useful. Al l Heensod
IJroadco~ting at at ions in operation a re
gin'u in th e i ndn, while only those
which hove mad e ape cta l f t por h to
RADIO DIGEST, are given in th o st ation schedule list.
S tation Sc hedules
www.americanradiohistory.com
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-,
Blrm lnll ha m. WSY
Mobil.., W EA P
lIo n t c o mer y, WGH
aOn.. :
PhO\' n l~ KDYW, SFAD
'(ucaon, K OXA
h r l $mllh. W CAC
Li ll ie noc!,,:,
"'-CA. ,
W ii:.AX , v.'S V
Pine- Blutl'. WOK
a.utorala:
"lIad en.. K GO
~lI:e ...lle ld. K D Z e . KT I
JI... r k..lel', K Q l . KRE
£1 .Mon t e. KUT
£ ure-ka. K SI
....... no . K DZH. K)l.1
Glenda le. KFAC
Gr id ley. K nJ
Ho ll yWood. KGC
Lon l" Reaf h. KsS
LotI Al toa, KLP
Lo.. An&"elell. KDZD.
KD?F. K DZ P. K Ft.
KHS. KJ C, KJ S . l\.NN.
K..' l
KN Y, KNX. KOO,
ON, K QL. K D S. K WH,
S. X1'.I. KZC. KZ1
uto, KOQ, KXD
lIotIl en,.. K LN
O:I.klLlld. KLS. X L-X . KZM,
KZY
Puade-na. KDYR, KLB
Pomo na. KOF
R Hd y. xa c
R...., ood CIty. K DTS
foacramenlo. KYQ
}\lin DlellO. K 'JPT, K DY !ol,
K D YO. K YF
g"n f"ra.n cl _
. AG I. K DN ,
KDZO. K DZW . KDZX,
KG B, KI'O, K SL. K UO
Ran .Io ..~. KQ W , KSC
6t o<'l< lo n. KJQ, K W O
BUllnyvale, K .lJ
COlo rad O:
DllUlder. KFA.1
Cclo r ad o SE rI Dl. ... KlID
~KrJzu..oK:;7~~aI·
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a ...."n lch . WAAQ
Ha rl f or d. WDAK
1'...... H . ven. WCJ. WGAH
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WEAl';, wTL. W JH,
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WPM, W W X.
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av.
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\\'0) [, W S D, 4CD
Collese Park, W OAJ
F o rt "mlth, WOAn
Sa " a nn a h, WOA v
Dliliola :
Chlral':o, KYW. W AAE',
"'BU. WDA P, WGAS.
W OU
Docal u r . W B AO. WCAp
....orla. W RA E. W F AP
Quincy. WC AW, W CAZ
~l'r1nll"nel d. WDAC
Tu.~la, WDZ
l'r l>a na. w n n
lD41a_:
Ano.l~ r ..o n.
WM A
f'ort W.y ne. W F AS
[nolla napoll" , ' VLK, W OH
R khm o nd . W OZ
!!-outh Hend. WBAQ. WOAZ
T H nI Hau l e, WEAC
W eat La f.)·ette. W SAA
10• • :
Am .a. W OI
C.. nl~"·1II~, WDAX
0.. (,rlPOrt, woe
n.,,, :"Io ln llll. W GF
F o rt DodJl'e. W F..AD
10 "'. CIl,.. WHAA
SlH!na ndoab. WO AJ
f:loul: C'Ill'...~VEA U , W HA E
·aterluo . ""EA?, W HAC
Kaa.aa :
:Antho nl' . \\'BL
At ...llod. WEAD
E ldo rado. W AH
F-mllOrl.. W AAZ
1n,le~nden('... \ VFA Y
L l n rl ~hor &. WOAD
Ma n ha tta n, WTG
SAlina. WFAD
n"hll ll.
wer
WAAP. WEAll,
at.,•.
City. Call
X alitackY :
l ..ou l.... Uf". 9ARU
Loal.aiaJl. 1
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W AA C. WUill . W CA O ,
W G\' WWL
S hr",·e Po rt. W A AG,
W DA X, W GAQ lIalR.:
A ubum. WUB
J'anford. WFAR
Kar'J"16D4:
Ua IUmll r". W CA O, WEAr..
WKC
. .... achua.tQ:
no..t on . WAA.1, WFAU
J,l l!<lto rd HllI.. lde, WG J
x e w lJe.dtord, WDA U
S prln&"1!eld. W B Z
weece e t ee, W CN. WDAS,
WDAT
1IIc!L1l"u.:
Bay C ity. W TP
De arborn, WWI
De t",lt. KPO. wcx. WWJ
Ea.t Lan s lll&. WHW
F Un t, WEAA
Superl(lr , WFAC
x m -ta:
H ut cb in ao n, WFAN
M lnneapoUa. WAAL.
W BAD. WBAH, WCAS,
W CE WLB
IUdJl eld, W CAL
S t.. Clo ud, W YA!>{
8 t.. Paul. W AAH
M1a101lr:l1
B r ..n t w ood. WFAK
Came",n, WFAQ
Co lumbi a. W AA N
J .. lf er" on City . WOS
KAnaafl C lly..t WDAY.
WHB, WuQ. WPE
St. J08e ph, WEA K
>;1. Lo ula. K SD. WA AE,
,," CK. WEB, WEW
M on tana:
Grcst Jo'all ll, KDYS
" ab r a d :. :
Ll neoln. WCAJ. WFAV.
WGAT
Oma ha. WAAW. WOU .
W OV
ncenvuie. ' \' EAV
... .. . d .. :
H" n o, K DZ K, KOJ
".11'
Ramp lhire :
n eenn, WEAQ
••11'
,;y.n e,. :
Ca m dan. WRP
n eat f1eflch, 2XJ
Jer s ey City, WAA,T
),l oo l·elltown. W8 ,\ F
N"wsrk, W loAM, WEB.
WJX, WJ Z, W OR. 2XAI
N . P lal nn Oll d...W EA!\1
l 'atarllon, WvAN
... .. lIa.lllo :
Ho pwe ll, KNJ
lo:tst e College, K OB
Ifa. Y Or k I
AILa ny. W="J
B ln xh "mto n . WFAX
Uroo klyn. W(lA C
Il u lf lll n, WGRl. WW'1"
e..m o n. ""CAl)
lI hncs, WEA l
New bu r g h. WCAB
:-.-...... York. K DOW , WHAT.
;:~~ll,
W DT, WVP,
P o u Jl:hk MP..te. WYAY
R o.·h .... t e r. W H Q
Il ld ll'e w ood. WHN'
iolchen &Cta dy. WGY, WR L
iol~WFA"';' WBAB, WDA I.
T arTY t own. 'W'R W
l : UCa. W SL
W a l er f o rd. WFAG
. ortb Caroli na:
A.. hevllle. WFA J
Charlou~. " ' BT
Iforth D U OAI
Fa rJ:o, W DA Y
ObJOI
Akron . WOE
A l h en a, W A AV
ca ntlin, WWB
Ci nci nna ti. "'·AAD. WIZ.
WLW. WMH
Clev elan d, WHR:
Co l u m b u... WBAV. WEAO
Da y to n . W A I. WFQ
Deft anee. W CAQ
1".lr nel d, WL-!
Gran .. lIl e . WJ O
H a m ilton. "''BAU, WRIt
Le banon. WPG
RECEIVING RECORDS?
WATCH 'EM GROWT
,I
H E raee C'OlItiuUoNl ! A ma UoIlt'8 wh o
a r c a ble to B EA T THE HECQR D8
1i~ted ~low, o r wh o U . Il d a im di , ·
aae ee recci\'lug r ff olda \ 100 m i les or
•~tfr) lor aht lan. not Isted b elo w ,
hilt which a re g iv en in th e bec adea et ;111:' d ireetory. need only ,,(lnd In th eir
r :.o r ds to b e listed along with th eir
" 1m....
ODe cond ill on emls.
E very r ..eo rd
I i rant ~IUST GI VE tbe NUMBE R
MI LES r e p r esen t e d by th e r eecrd,
bi ~ l ..tt ee i n. t o h o conaidc r cd. Other i t will be t h r o wn out.
rd ~ to d a t e Pre Ri ve n b el o w .
-Broadcast Edi tor.
S t a " City Ca U
Marl eUa. ~"" B A \\'
I 'ortsm o uth. WDAB
Toledo, \V BAJ. WHU.
W JK
W oo ster, WOA U
Yo un gllt own\vW AAY. W:MC
zen es vtn e,
PL
0 1l:1a.hnm a :
l l ullkog ee, WDAV
Okl shll ms Cit y, WKY,
&XT
T u lsa. W EH, W OAF
0 ........11 '
E u gene, K D7..J
Hood River. K Q P
K la math FaU... K D TU
P ortland , K D TQ , KFAB,
KG G. K O N, K U W . KQ Y,
K YO
B rld &e port. W"BAO
Brll"'nllv llle, " 'DAQ
Clearll~ld.
"'- PI
W W.1_ 2.200--F. W . H ill CrIl1tobal. C. z.
WW"Z--415- H . S . Ra hl_r Pitt..bu rgh. Pa.
! X A I- Sl o-H. S . Rahl ae r ...Mnabu rgh. Pa.
! X I~50-H. S. Rah lMor. J-Ittabu rgh. Pa.
t X J - l.toO- c. G . ).funna, Hol s in&ton.
K s n..
•
fCD_ISll--E. Dah lnen. R ice L&ke, WIs.
ITA-t7G-E. Dah lg re n, Rice LaJr.~ wte,
E r ie-. Vi' .IT. W8X
H arrl.. burg. W B A K
Lsnc~ter. WG AL
!oIcKe1'lIporl, WIK
Phll lldetpbl a. WCAU.
~:8t.~n1F'{\·~·G AW.
N ttllbu r g b. KDKA. KQV ,
Vi' AAX, WCAE WIlAF
·V lJl ano va. WCArol
W ll k ea- Barre . WBoAX
a h od. l al . lIA:
Edge ... ood, 'V EAG
Pa... reeeee, 10 .1. t XAD
Provld l' nce , WEA-V
1kI1lth. Ca roUJut,:
C h.ar ll!8t o n , W FA?
Oran!lebur lf, 'W G AY
Sonth D aJ<o ta l
Rapid en s. W C AT
Sio Ull: F all a. WFAT
'I' '' IIII. a. '' . :
~Ie m phlll. WK:-'- . WPO
N.,.hvllle. 'WDAA
WSY Inaugurates New
Service for F armera
BllUoU:-.-G HA).f. ALA._1naugu ratln& •
!!en-Ice- ot Ilpeels l b.mellt to the t armel'fl
ot Aisbama . l U ..alaa l p pl, T e nne _
and
Geor g-fa. , .... S Y .. t at lon ot th e Alabama.
Po ... er co mpa ny lMlgan ~lond a y • .l u ll' 3.
10 broad ea a t m arket Quotallona eve-ry a f t e r n oon " s.ee pt S u nd . y a t !:30 e'eteek. Thla
w lll be In ad<l'lUon to th e regular u l ghlly
co nce rt .
•
C IOJ'llng 'l UOta t lOn ll will be broa dCll at<~1
ot t h e :-'-toW York Stock Es. eh.nlle, I " e
:-'-e " - Or lcan" co lto n mar k et, the Chl ca~n
Board ot T r a d e. L iberty bond 1>rlc~ ... a n d
loca l Quo l ll ll o n K on trults . produce, n "h,
g raIn. t ee d lltutl' a nd po u ltry . Crop re _
ports an d I.. ctur-e s d enlin g on a gr!culluraJ
lIu bJee t ll w ill RlllO be ee n t out..
'1'. . . . :
A ma rlllo. WDAG
Au .. un, \\' ClI
Ds ll a ll.
WDAO. WFAA,
WRR
EI P u o. WDAK
Fo r t W orth . \VBAP. WPA.
Galvell((>n . WH AlI
H ou "lon , ""-CAK WEAV.
W EV, WFA L . I VGAB
Pa rill. WTK
P o r t A r t h ur. W CAH
~a n A ntonio. W C An
U tah :
Ogden, KDZ L
S alt I, uk.. City, KDY L.
KDZV, K ZN
Ve rmnntl
Bu r llngt on . WCA~
Vl r lfl,nla :
N o r folk. WSN
R Ichmo nd , WIlAZ
W a a bl n l!rton:
A berdee n. KN T
B elll n lt"hnlJl K DZ R
Cent r ali a . k OZ :M
E \·"retl • •KDZZ
l .a cey , K O Y
Pull man . K FAE
Seattle. KD7. Jo:, K FC, R R Q,
KJ R . KTW. KZC
Sl>oka m.', K FZ. KO E
T a coma, K G B, KMO
W en a tc hee , K DZI. KZV
Ys k lm ... KFV, KQT
C oncc s-t e t or I'a Uent a whil e waltln !!" In
the phY l lclsn' e cmce l a the mo. t u p- eo-d a l e
us e ro u nd tor m e R a d io p h on e. Dr. Pain..
Flt~Gerald , of BOllton, III t he phYlilclan
Who h aM long bC<ln 11 lIndto " b u ll''' and n OW
cnter tsln " hI" Illek vs tle n tB w ith m u ale
aud lectu rell w h ile w lll ti n g t o Bee h im In
Itl B e r nce.
JlTebrrul
No. 18 RHEOSTATS
W.n""~:
EMBODY TH E LATEST TH OUGHT
IN APPARATUS DESIGN
Chsrleaton . W AAO
H u n tln g t o n. W AA R
l forxan t o... n. \ VH D
W J. eo n . m :
l!n....ukee. ,,-AAK,
W CA T, W H AD
:Ms d l1lon. WG A I" . \ VHA
a. nt It-. II ."""
EuoeIl . 1I&I
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Froo
P ol'1.o a leo:
I.
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f
IN. ,.. . _ 1 N Jtd_
I le _
" .......
ef
tbla
etI_.
MAKE T HE NO. 18 RHE OSTAT
WORTHY OF YOUR
F.n senada. W GAD
C aDad... :
Ca lJnl,r y . CH S C, CHCQ.
C FAC
Ed m o n t o n. CJC A
Fo rt F rances, C FPC
HILIi!ll~ CFC E
H a m il t o n, CKOC
Lon don, CJOC'
lfont real, CFC F. C HYC,
CJ BC. C KAC
Otta .... C HXC
R egin a, CK CK
S t. J o bn. CJC1
Toronlo, CFCA, C HCB,
C HCZ. CHVe, C JCD,
CJC~. CJ SC, CKC E
V ancou ..~r, C FC B. C FYC,
CHCA. CJCE. e K CD
W i n n i peg . C H C F , C JCG,
CJ ='I C, CK7..c
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s...t_ ••, .. u .~1e
H . ...U :
KIZ -1So-G. Wh l ~m an, Spoka ne . \\·a llh.
K JJ-7fo-R. C. Bryant, Cl a rk l!to n , W u h.
KJR-29O-0 . Lombard, MII'ol'n , Wuh.
K LT>-t ,300_H . W llntu ck . Fllyethvlll e. Ark.
KLZ-t,515-C. M. Rlcc Jr" WOreelCte r ,
MaR".
KN J - 1.150 -N. M. H olme", C h lp pe....a
L ... k c. O.
K OB-l,&SO-C. lIf. R l<.'e J r .. WorlJ....I" r.
Ma......
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WR W - I . t50-K. E. Gabbe rt. Clay C enter.
Kan.
WS8-1.800-8. S. " B .. ttl' 8 ," Cll Da! ZOne.
W S Y--C 5&-D. R. Ba rtaeh. G alen ... 111.
W\~ ~~%6o--c. C. ~fa y heD. J r .. !dU.... ukl!i!.
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KDAF-56!J-S. w. W lIIl.In.s on. Kno:n lUe,
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KDKA- I ,I iCl-D. K eigle)·. ~t1am l, O klR.
KOX_ l .G&&- E. Dshl l<Ten. R Ice l ..ak e. W·Is.
KDOW-3&" OD--F. Nich ol ..... Ealllon, Pa.
KDYQ-' .• SO--C . )1. R1C'1' J r .• WOI'C""ler.
Ma lIS.
KDY&-2&5--G. Whisma n. f!po ka nl'. WSl!h.
KDZR-26ll--G. Whb.man, Spok a ne, 'V.... h .
K FC-S8o-6BNG- W a lsonvi ll c, Ca li f.
KFI-fSll--Dobson ,. Tu cker, Oak land
Cal.
•
K F'U-160--D. l ..om bllrd . ~r" ld en . WllIlh.
K I''V- 1So-E. T ho ro t o n , W alla Walla. Wal!b.
K G B-t So-D. Lmn Lard . ),f.. Ml'n , W a llh.
K G Y- : 6&-D. Lom bard. ),In.l<1en . ""·.... h.
1CHB--65G-P. A . Rose. T w o IJarbon,
M in n.
KHJ-310_D. Wolfe, Sa.n .re ..e, Cill
J..: H Q--2,400-C. :'>1. R ice J r .. W o r ee ..t er ,
:'I a l!~ .
W HQ- 72~ H. W al rath . Ce dar Rapid .., la.
W l l -6' O_ J . K . Stslfo rd. D ecntur. Ill.
WJH-I. OOo-R . O . WI se, vnnsee. Ia.
W JK -~1 &- H. I~ Jo:\·s ns. Jo"olsom. W. v»:
WJX- 6iiG--R. !\-t. /Un foro. A tlan ta. 011..
WJZ--S.OOO- J . J . B ea l u . J r .• San A n.
"elmo. co.
W K.'l-750-A. N. H o pk i n.. Allh t a b uJa., O .
W K Y_ 4UU- R. O . W I""" vunsee. re.
' ....L B-no-W m . Davia J r.• Ca no n City.
Co lo.
·WLK- U&-J. S . T homps on, Toro nto l Can.
WLW-600-Wm. H al land. B r oo k llne, " l a.sll.
WM H -n5-W. A . Kn IKht ... H ud llOn. 1-la.....
W O E-21o.-E. Dah la-re n. nice Lake, W is .
W OH- 97o-!tt . SlmmolUl. Rhreve POrt. La.
WOI-&Oo.-A. K S trong , F IlI.S'le r . Colo.
W OK- r oo-t'. D. W~lI .. M U... uk..... Will.
W oo-t oo-U . S . Rahh,~ r, Plt tabu rs h. I'll.
WOQ- l. IOO-O. W . Pull in i . Thorn"" n. N . Y.
W OR _ 95 o-F., Dfth l ~n, R ice Lake, WIIIl.
W08-46o-lo:. Dah lgre n, Ri ce Lnk e, WIll.
W OU- .UG--H . S. RA hb~r. PU Ub Uf'lll h . I'-.l..
W RK-tOG- R . O . W il e . Vi UI_ . l ao
'WR R- I,OOO-Lee
A u p atull.
Ypsilant I.
SPECIAL CONSIDERATION
R ESIST ANCE . OHMS
Price (In U. S. A.) . .• • • • $1.10 each
JlTebrrul
No. 16
VACUUM TUBE
SOCKETS
ARE REMARKABLY RUCCED AND
STtJ RDlLY BUILT
xo. " v. T.
lKlClU.'T
W e have no hesita ncy in cla im in g that the
NEW NO. 16 V. T. SOCKET
lS
wi th out any q uestion the best socke t o n the m arket
Price (In U. S. A.) ••••• ••••• •••• • •.... $1.00
YOU CAN DEPEND ON
.:If ebera( lltdepbone
1l!eberlll
&,
GUARANTEES
lltdelltapb lII:ompan!'
BUFFALO, NEW YORK
CHICAGO BRANCH OmCE: 805 STEGER BUILDING. CHICACO. ILL.
RAD I O
10
Rddio
Djgest
11I\lst rai eil
T R40 E· IIlA AK
E . C. RAY NE R. P ublisher
123 W E ST MADI SO N STREET
TE.L.EPHONE STA TE ...e-4M5
CHICAGO. ILLINOIS
-"
P IJ D LlaH lI:D WEII:KLY
IIUBSC'R IPTION Il ATS8
r .. rI7•.•..• ...• ..•..•. • &.00
8 1••1.
I r ...-.l.I II _
Co P.... J. c ...u
DI GEST
IL L U S TR A T ED
Ye Ed Asks 'imself
QIlt'" titm .-WI.at Ur ' h g"""o l plo .. of Bodio , .
ClI,/lim'
A UlI Wet.- WhcD th o Ra d io me8llage is sent a signal is
l:!ncrgired in th e ether with ele ct rical COt't'gy ha ving vt brat iOilS f rom (i\-e to fou r milli on eycl~.. Jlf'T eeeond. I n
tbe reeei ving lIet t hNe aigna ls r eepond to a set wh ieh
is tu ned ill electrical eeecuanee for the ty pe of signal
which is sent DuL I n lOme rt-eeivillg It'ta this signal
is r educed in freque ue! bcfete it is II mpliiit"d; in oaer
word s, the f fE'qooney 18 ehsugt"d from Radio treql.lCDI';1
to a frequeney ,,-Web is ,.. pablo of rteeptioD b1 Pl ea.Da
of the hUDl lln ea r . III ot her reeeinng sets this Badin
frequency is detected by means of U1e deteetee lamp
Rod is thM. amplitiNl to the req uired a moun t be fore it
is eedeeed to a frettuene1 lIUitll blc for rcet'l'tion bl the
hu man ea r .
In ordinary ttyataI roeeirlzlg ..ta it. ia a11r3o, 1 eustomary to r educe this Radio frequency to huma n ear
frequcner. aad then amplify llUclt a . ,ystelll bt the regttlar
RADIO INDI·GEST
The R adio and the Lad ies ' Aid Soc iety
Bobert &ewur t BtuHfI'e .
T ho MilI viiJ e goll8iJl' use d t o s a y that Seek,. B ro wn
could talk
day; ' t waa T ra ·la ·La and Far·aoodiddle,
her tengue was balanced iD the mi d d le. ADd thou gb
good rt"eord. ot h!'rs made when T h um a y met th e
Ladies' Ai d, Becky 'a elae k the m all "'oul d d row Zl,
ahe ' d 8tll rt and talk the w hole bu nch dewe.
One quiet dame, lofiaa fi ilds SAOW, just JisteliN j
b u t th e Rad io, had eom e t o to wn , a nd Hilda ' i dad,
had gut the Radio re r ee bad. It .ouud ed )ond the ti m e
an
~u.
00
~.rli<»l.----G'oftmt"'CIble dia~<n' if " nag rtriutl ..
~gartl to tile e#icieM:J
crrdal ddMtor m 3. TAil
dirclr.srio1t IlI'i$u pal1icwla.rly
10 I "
raage '" .au
QI
•
a.
of ...:A <J 3d. JPlud U 1M _ iktJge of Ihe ordlAar:9
l a . . . .... _ 1...UIIe 1Ie.,1 ... ..-... .......,. ... rll ..... re "".orl...U".
.:ry3tGl 3dl
: ,t~~I":t~:."r:..:I~:'~=':;'."'': :::I[:~:;:'':f",o:~ ~~:.:~::=
AlISWi."r.-A large· Dumber of muu faeturers bve p ro tb~ ... c,ontro.·..... _
...,. boo 1.1Il .. 11 11110 tb.. court. for _n.. d uced sets, tIl\·emg wave It-ngtbs of two bond red
fo ur to rfse, a t bre:akfllJlt ga" e hi m .arninga wiae j a t te n it.
m~DL
T h . prl..rll,. of IIIy_tlo'" m"", ' "
t b . . . .rlU ot _
.. pu1.
t.rI .. . 11110 I ' " ..... .U U"UOD of t he
told wbat eggs were ... ort h, th l"u n ew s from all a nlUJl.d
hUlldt'ed lifty meter-. They have been cuefuJ m the
rad io . P.... ,.ID.. Th. 1lM
D'~ I. Da o u tl"'" t or _
ItSt he ea rth.
produePon of th_ llet. not to I('a d the purdur8enl to
1'''-0''' ."" lb. publllltlM' dJ . . lII.I.....",. ..... POD.lb lUt,. for
oplalo ... o r _ ,.......u ....d . In _"...,UOII _ 1I-b radio .. ppn.A t noo n it gave t be d inne r ca ll , at five who'd 'WOII
believe that the raage in mileage of t.1Joese tete 1fU ext .... Ttl. a._. ~11 be prllll ad. ... It " .. mea to u&
the dar 'a baae blU; a t seven a ee eeert, th en, a ta lk
traordiu.ary. In p rod oeiuJ[ t he set they have simply
stated tIIat it .mlld ~i ... e certa in lrigDaLt and have on thi~ that .8y and tilOft' that wa lk. . 00 J u pit e r,
S o. t
' oL D
been abo eareful t o l peeify the wa 'fl! k gth in mE'len. tb e ],[jJlr.r Way, Oil .hat · had happened throu g h the
Thill use of the term. ".'fle le ngth me te" has ea used day, aDd ! ilIteDiag Hilda. i ot t o a ltow, about a million
ton.sidE'r abhl eoofosiau in th e m ind at t ho ordinary thinga or 80.
R adio and -th e Women
I n H il da ' a b r&io WUII . traightwa,. bor. II 8d!etne t o
pa reba sera u to the e f6deney of the seL He hu inlmeMany Opening. fa r Wom m. Are F ou nd in N ew Art
diately jumped to the eonelueicn that t he SpeeiJJ"c;LUOD eu eeee Becq '. horn; fo r _'eo h(I\JflI e t·ery day. she'd
H E GOVE RNMENT now renders pea ce time 8e tv- of wa ve I('ngth nUl"" in eetere represented in milea the l ist e n to broad rad f'flI'
She ' d hard ly atop to slee p
lee tor women who lqI n t to delve into the myllterica t olal range ,·alue at the reeelve r. Unee eupulcua d ea lel'll or 8Up, but like a ltp01I g e jtJs t so p ped it..-OJ.p, aDti t ben
of Radio. F or thoee ....ho "ish t o take up Radio noting this e treet I,av e added to the present coefuaioa
eame Th lltllda y aft..ru oo n, and with it. B e r k y 'a en das a p ro fesa ioll. thore is a dtaaul to h.·1UII. the meanin g by lea d in g tho p ros pect ive eustomer to bclic'fe that his le811 t une. But IIOmE'thiag .toppe d h e r wual d in, for
of the d Ola a nd ~b ee o.IIed in thE' Inte rn a tional Morse illterpre tation of the WIl\ ·C length a a total . reffpt ion
Hilda r08e and b utted in.
Code f rte o t: ebarglC'. I nforma tion in detail will be sup' of mileaR'l! wa a co rr ect, a nd it Is on · t hia aceouu1 prin"s he talkf'd of s tara a.nd at the au n, of ball RJlIlU'" loat
plied by writing t o thl' neftrellt; Army hea dquarters. cipally tha t a good lWlnr pUI"Waaenl of e,," Ita l det~tor and ra ~'t'a WaD. of h b torr, pla n t a lind of t he tre("S,
LeS!lons will be lJl)nt b y mo il, lrimplo leMOns, IlO that a M'ta MV(l· ~orne thorou ghly d islla t ildied with Radio of shoes and hats , ot ~klrt , at kuees. T ilin gs of the
Mud ('nt at avera ge education may unde n tand and grasp l'ecehing appara tull.
lla~ t , lind thosc to be ; rchea rllC d Ibe lo all, f ro m A t G Z.
t he p rin cip les. Go\·c rnmen t inst ru ct ors will eorr~t the
And tllt t'e I'l ra ig b t I,OUI'll went r u,bi nl!" 1'1I ~t , III in a.
I t h IS aho ke.. fo und tllat u nd er ~od co nditlona
IPlISOns.
l't'o.'Cpt ion hn a ~D obtained with un or d inary IOJ7s tal 8<'t t ra llCC ghe held th ew f allt ; IllHI n.... k )· n lown leeeh·t'd
W om..n BadiG Gpera toTl will be in evidence in t he from two hunJn.d to b :o huudred fifty mil_
Th is is 3. rout , she miut ed a lUl wa ~ carr ied on t .-Wo rcester ,
ne:r.r f utu re dC*pite 80 m El pre!llmt p rej uqic es a g aimlt t he ir excep tio nal, howe ver, fo r s hor t wa n l length • recep ti on. M a s~ ., T ,·ll' gram.
lIt'r ..iet'&' It is eilli ml'd t hnt shi p" never engage wom en Use h lt ~ a lso been mndo of thia f a ct to Cnd ell'l"O r to lIC it
tt ~ Ra d io opt.'Pllt on, h('('ausc in the ease o f neeid ent, the
the cuslome r auoth"r se t claiming t hnt t h" IIf't hilS go ne
Boy, O rd er O ur R adi o Funn el s I
Ra d io op er:l tor an d t!Jc cn p tn in 1ea..es t he 8h ip la st . Tb is de foet h·e. Endt'IH·or ing 10 mnk e s ucb a ~le the deal er
wou ld in lerfe re wilh ti,e Ilnll.lt ernhle code of "wome n and haa Jxoe n fort"t'd t o ~JO('tlfl !J,O mile ll~ fC\'Cption of thi!
Cvi1a, ffllltl'·,I.....n, rl",""I/l I~ ,
child ren firsl," yet women telcpllOne ope rators hm ·o mlltnune nt lin,] I __ D II(" nt hia re luct a nce to IIctually in·
.o\ J!II' wh isk l'u f rom lh ,· CIlb,
proTen t hl'lr brlll"l:"f'J in lh e flll'e of d isin t er b Y9 ta yiug at form th e CIl~tOllw r the IIctua l mill!llA"e mUler t h rough
~'('1TI1! ti l(' lullt feIV mo nt h" or 110,
th eir \'Ollia for days a t 0. strct("h.
All 1\"(" " ." 1'~'l'I rd is ll o,lh,.
Rali lo ill ope n 10 women ill litany la nd IItalioDlll. It is i~ofllnce or otllt' rWiSll lm hu ill genera l ~ificd a ra ngl'
of
50
miles.
a- rta in t ha t ",·I,eu womeo prove th em~e !ve9 proficien t in
" T inkl·r" Jill" '" eame from nfllr
Ita g t'lleral it moy be lllI i d that m usi c by m PllDll of
thia new field tlle)' ;:Ire bounll t o be in d amo nd.
T o p:d soml' apa re l,a rt , fo r h is ea r,
pn!sen t lJrO:llll'a sting SJstlllns Min on11 tit' lwa pd with th t'
Tn :lnd Ollt U.. • lIlo",/< b(.'d jiO,
dina ry l'ty 81a l !It't d urin g SUllllllcr mon tha .t a di-~'u'l'e
B ut a ll he fOllllJ wlla Had io.
Lighlning Not AUracled by Aer ials or
of from five to A. mn ximu m of tl>u mill'S. thb r:1:ngl'
Sm . lI Wire in Ae ri l l lias Little E llert
ca D on11 be Ilb ta incd b~' mea us of .a a "telUlli ay!rtem
WiIli.::lon P lum, he looked for pluKS.
T MAY be of in terest t o tire many Rad io faos t ha t lit lealilt one hundred fifty lon g, mou nted i• • SIItW a.etol7
He go t >10 ti!'t"ol be ueo.'t1t'l! drull'' '
the tire llevartmcat of lhe city o f Ke'li' Y ork has man~r a t lea lll fift y ft'Ct mm the g ro o nd. A eryMa!
I nto /I d roll: Blol'J" h" d id KO,
Dl'\"er ha d D fire 011 rt"COrd 1U.t Willi e&WIO'd f ro m Ii!:"htning reui'fiug lill"t Mould not be depend ed o n to l'('s!lOnd to
A nd a ll he found \Vas Ha d io.
f ollo wing aa .erial whether it .... a p rotedM by .rn'.slt"!'S music: broadeasta with an indoor aerbl
I n a n "mer t he re is /I d ..rk
or not. If t h is is the eue,
should the drutic regula·
Wh o l ell. the Ix- I"."" killrd wilh wtIrt.;
ti on rule a p ropoM'd by the U ndenrriten be eon.sid e~ a t
Ob! if t he 00... ("()u!d '"-' tbil bo,
Q1lUt w....- TIIn- " u~ Jq to be oo,..iderable a rg _ t'lt'
all
Ilia phone hoob') 0 0 t h... Rad io.
I...iahtning ill nothlnll: more than II dicharge o f high lSll la tJl" IW'f'nril, af lYing II 1tig1tly tI~rint ' e leplwae
po te nt i.::ll of electricity be tW('('D t\t o objeetiL Th.ia ma,. ..1tid f:l 'oowdm ' " uri8I citlt an ordiMrJl fllJtplyfr"!J
Tigh
t...-ad J Ohlll101I -O n' di d hilt...
lappen boetllfeoen two clouds or betwet>n II e10ud and t be 3et. .Adri3 e s-Itd1,w .. " or dinar y te lep hone rtt'~f!i,.g at't
To lIICe tltt- ua!l("r l' lISII the pla te.
l!'I' rtb. It b axsumed th at thE' t'lIrth hll6 a charge of i3 .tvit46u trw ' lie ptf 'l'03e.
~O\'f 10 ehu rrh hE' d"e. nut ';:0,
el"""triodty at aD tim", and .... ft ma y rail thill ebs rge the
A Mwer.-In a aysbl reet' i'fing' M't ther (' ea ll be DO
Ile ja~t boo b uI' tho.' Ra d io.
posi th e. The bot, dry air makf'a a ~d insu la t or be- qlll'lltion a:l to the Itett'&'lity of I"IlIplo~ t:.lw- IDOlII f"l'fi .
f1w e n the d ouds and the Mlrt ll, but if the clou ds ha ug
When you ~ iDlo tbl:" s h0l'
' t 1J!P o f t~l,ho n.. rt'<:"eheN. Tbese a t. ' - t trill give
10.... a eh rge of elec tric-ity ill i..l uf'f'd in tbem by t heir delt
on l.r ordina ry 1'C!Otllts ao t bllt it will be ob,·ioull tbat ao ia·
To l,aTr , .... !'art..r ('Ill YOllr mop,
d _ ness to tIle ro r th a nd Ih b eharlte ig the o pposite to ("ffi('1ent t ek l'b olJe ,,"auld ,....ke the . igna lll very Lud of
Y" 011'" W"lInt to , • ."jt , . li lt hnur or I'll
t he ("lIrth's eh arg e. If a ....i nd II;pri nll:!I Dp ol ber elou.!U
And li<den to hill Ra d io.
...i11 fIltiftl,· 1*S11 Ote ebarll:t'd e lou,) and "':J.a opposite ree ep tion. It is, o f roaMt'. to be ondenltood thllt ;I
r ha rge b indueed in thrm aud t hen II ftash oeeun. Tbe I'I,OIH:!" ~tl!li::ding of Uwo1pt'naive pa ris will Dot .IMd tIw
F.aeh day WE' _ «lDl" Il("W ,I"vi"'e,
ai r betw('O.-'n tbe rlonds is broken d owo and the disru ptioo ","r a Dd tf'U as _tilliact orily 118 a !!et ,..Il.irh is ltIade
A f n'qwllry n')('uirltp r or eah\.e ~ pl,",.
of
good
Dla
tetial
llAd
buil
t
fOl
tOVJth
ttelltJDe
nt.
E
n-It
ral.lSf'6 a dowllJ>Our o f rain.. If the elollod eomea _ear tbe
P r...w"tion hllll it IJfJ\.... h ,viii tfo _
t"&rtb tltt' same eof[t'rl ia pl"Odneed a nd th e flash ot Iijtht- if[ a n ampli fying set t he best t y pe o f tclep holl1"ll should
Through t he :lPIloe,. of Radio.
ning will be between tbe doud a Dd the ea rt h. nia bUrr a l">O be aaed.
In gtllrral it. may be &/lid lhat til e purma""" o f a bigh
ClI!Il" is t Il. OJ1e l.hat ill of greatelt illterest to the Badio
j!;rade tt"lep hoDe ti"C'eh'er is a booolute l,. nl'Cf'aAl'! for good
A ll for a l"iekle
=~
'rUe lightning dill('barp mar be lII&IIy million TOfu.. Radio ree.!'pl ioa, ev('n thoul{ll. an amplili er is Il8e<I.
A t II; ,l"i.......·Ra.lio ,I..m"""t ral io" in :-;.." Yor k /I
II lIOunda dArlJ:rro~ and is ob.ngtoroas if r ou are in it s
eOlWee tioo wit b a ~mp .....!u·t O,"'PBt Nl II faD, Ug h'lt'd
pa Ur, b ut t he llgbtaing is not guiltl OIIt of ita _y to
a IlImp, be1Jled 110 , ...n :tn,1 l'ro<l lleN • Ra llio l,rOll:llllll
Qwu~-BoMl '" fh e l eagfll of a ll a«tol d tt eNRiRed !
m.....t .run. The Ib tJi f olloW1l the Ii_ of least J'etiistanee
/III lit oue :Iud tI,e SIInte t imf". Th e on l.1'" ,..a801t a hair
ABa"II"er.-Lea~a. of t ither a o iIIdoot 0 1 ou t door
tlIld tales til(. ahortest poesible path to ~h.
S UI're- the eloud is IlUDging oV'l'r roor aerbl and i t n('r w a re not p,Nf'tennined . Gf"Of"lBl m in, Ilollfever,
is Ihe e1081!'f1t point towllrd the ...rth. If you. liIyli1em noquire that it be, a t Irht, lIl'! 'ff'nty· lIve f t"f't 101t!!:, one
i. 1,ro l>t·rly grollndeJ. it _,.. drain th(' eloud of eneu!tb h uodred to 01H' luu.dnd t ....en ty·fivf" feet beiQR, if p<JII.
(>ON J:Y 10 mllb it incaeeul"e. Suppose the eharge ill aible, :l. better lenglh to use. Alt aerial of t h is tyPf'
tbe clou d is t oo bea vy fo r ),our ae rial to d rain it, or too lOhtl1lld be mounled , at le llst, thirty·lif'e feet above the
IiIlow t o m ake it ine lIcethll, then t he 11ash. oceu~ :mol gfound, a nt! pro,·ill..<l it ia properly inllulated s hould give
Il.eria l or no ae ria l the tla sb wnI readl the eartb, but 2 000 re sults. H ow.....e r, fat Ihe ree't'p tiou of IouI!' ....'ff'
ltOt th rou .l:"h the 5Ill:l.11 wire by .ny rnennll., ~ insig- IeUgthl, a t'Cln 9iderable lon~r /Ierial may be of d el'ided
n ifil':lu t Ko . 14 wirto uS('<) ilt mOlll Bennis wm not rha nge IId"lIntnge, C'Ilpceia lly ~n t he au mmer mon tbll.
t be ~tb of a bo lt of li g htn ing in. the 1I... n .
L lghln ing a rn'lltcn a rc used t o p rotect the inst ruruents
()llUti cm .- 18 it ,,,)$kibfC 10 1186 (I bed 8prirt{/ cu <I
from extra. 1ll'8 ' 1 c-urre" t surgt"6 eauSl:'d by execs!rive
l<tatk a nd from hi gh l,otential currents induced f rom satisfactory ant e/tna !
A ll8"·f"r.-Pror i,led /I bed . l'Ipriug ill located ill th f'
li~hhl io~ d u.eh:LJ' gt.'lI ta kIng place at II di., tanre , bat Ih('~
n rr,'!It(" r& offe r no p ro tectio n f rom :'l di rt"el holt of li.(tht- snmo Im ild injl" or close to tho loea ti on of tht> tran ami ttlnj{
nin g".
They will 1'0 m ore prot e..t ti ,e 1iI'\'slelll from lIt:Jtio n n hed sprinj:( nmy he I~ ...tl witb t he prol'(' r a mou nt e~!fll" r lind :t '~!l rlllinll" pad for II!! :tt'he Wl'r.. no t p ro.
\"ldeo1 "'-as t hn t uo o lle IU t h l' a ud lt'o ee ,."keol f or t ht'1I'l
lijl"h llli u l1; Iba n Ihe roid a kl'u id ell tha t a n a er ia l offers to l/f a mplifk:ttion.
I n I:.. n..rlll it l11t1y 1M. /;/lid thnt n b..d s print.:" o r sl miln r It r..min tb u ~ of tl ,... I,l<! d.u.~•• iu CO"",)' hl.land wht' lt th~
a ttr a ct flnell a holt, ~ n <! th a t i. nonr. I'll t ul ' :Ill a,'rial
nod UAA ii , Il l ~o u~,- a Jij:( hlnlnJ::' .,re ~t er for tbe IllI k... of nlE't hvlls or t' ilwl!l(·i("ut !lod {'IItlre ll' Itnr rMlienl for ba rk er, li.'il-d to cr." " Herl' .'" lln-! A "i, le 0' l"'e f, a
t he law a ull f u rK.·t nl,,,"t"\I,,- d llo.(t,· r ra lko"d . hout h y t~ or,lin:T ry 11"'".
lo a f" " ",ad .and 111' 1"\ 0' ('o h loalt e for II l1 ir " ..l ' ~ • •_
W. N. F llrthnllUl.
U Dde rwritl' l'5.
("It it' nlt0 l>a i1.\' .r\ 1'""".
.
,,1&1_ ..
_.Ii _
'0
sur.
T
I
-11,
1·
www.americanradiohistory.com
RADI O
DI G E ST I L L U ST RAT ED
11
An Efficient 500 Meter Loose Coupler
By A d ria n Van Mllf flin g
*
U IP L E di rections a r e hen- gIVl'P tor
the ecner rueuo n of a 1 _ coup ler 10
S
wide . It s h OUld th u s begin at a poi llt
In eh from t h e ed .. e of tbe l u be . The in_
du ctance Is calculated for an a!ltl'n na at
the L type 60 fee t high ... lI h a !O Coot
I<!'ad 10 the se t . The antenna Induetanee
III 185.600 centlm"len. The p r imary ..hould
b e wou n d w\th 150 tu rns ot X o. U .. l llA: le
.. Il k <:overed Wire. HI f eet o f wbleh ... Ill
be re Qu lred . Thi. will r ece l .. e up to w a \'e
le n l:'t h o f SOO m eters.
T h e coli 8 h o u ld be la p ped a t tile 15th,
30 t h. 45t h, smn. 1;;th. 'Ot b. 1000th, 12tlt h.
135th sD d 150t h ",·Indln g . T e n contact8
w ill thu e be reqUired tor the prim a r y tap
s w it c h .
T he lIe condary w ind ing c o n ..lllts of 100
t" r n" of X o. 30 d oub le .. Il k covered w lrt,
t h e len gt h of w hleh w lll r eRch D5 f eet.
Beve n ta ps on t h e Ileeon da r y .. w it c h
"houl d b e connected r e s pec t h 'el y t o t h e
IHh . 2Hh, 42n d. ssm. 10t h. Stt h nn d ~8th
tu'·n s . T h ill s et I~ desi gn ed to be oporat"d
w Hh tw o 43· pl a te conden s cr s o f .001 micro ·
farad" eac h.
Th e ~econdary term i n al s c a n be mounted
UIOO n t he b ase pl at", as Show n In the Illu ..•
I r ation a n d con nec t e d to th e e lide rOOs by
ml'ans o f c opper st r lp",- or thl'Y c an be
f a"len ..d dlreetly to the reee t h e mlle h ·es
w here t hey I..sue Crom Ib e s u ppor t D . ln
.. It h er ea.&8 a n eJtceptl o na ll y n e a t looking
outn t _Ill I'ea ult.
nceh". w a ve le-ngths u p t o 600 m er e ea,
Oee t _ IUt - of waterp«tQ(.,.), eanlboanl
or about '" Inch w all thJckn_
• Incb",.
klng II.Dd of I~ and I~ In<:bea out_I de
X u :! na ve you..
loo.·8 1 pa lte rom a k e r tUrD up t w o wooden
dlBu. A a n d B, or d l m e n sl o DII . . e h o ....."
In FI C\lnl I . Care should be taken to have
the r a llied iJhoulder on the lIl oe.. lIurrllce
III lI n ucly In ea ch respeeUv" tnlM.' with.
out forc in g the la tter Qut of s h a pe. A llfO
h ave him t u rn up a plain w o ode n ,J.l .. k .
C. to lit In to t he o t he r e nd of th e Inn er
.....rdlx>ard tu b e .
Xow hi Y o ut o n .... e h dl>l k two holea to r
the bra ll8 aU dl n g r od 8. Draw .. li n .. on the
di sks ~ Inch (rom t h e c enter a nd la y out
rne centere ;l,t a d h,tan ce of 1 Inc h In
ea ch direction Crom the b lll..., tln /l: d la m eree . Ca re IIhould be taken t o h a ve the
pOllltlo n ll oC t h e h ol e N exa ct ly a li ke o n
each di Rk. or binding may t.,s ult thd
will mak\O t unt nl' d lntcu l t . It will b e fo und
bl'llt to n ail th e dl .. k ll t o ge the r t e mpora r ily
with very th in bradll lUId d r ill the neree
In On e c ...e rartcn, p re fe r a b ly on a drill
l' rl' lIs to In llll.... per Ce<:t para lle Usm . The
s tan d s D. E and F lire a ill o made oC Wood.
In cb o r % In c h tblck . I n D. whl cb
fo rm. t h e e nd s tan d a nd support. the
b........ r od .. two holes! InclJe.. apart must
be d rilled to eeee w e the tettee. T ll& 8tand"
a re bfoflt fUlened to t h e ba .... board with
IIlue , o r t h e y ca n be ecrew ed from tbe
"ouorn.
'
..... . . IQb17 of I'I'tDI.&r7
The oUler Or primary t u be I. f lUlten..-..1
t o the . tand. ..Ith t o ur or . Ix scre....
w h l cb .bould have nAt h e . d !! SO lUI not
t o Inte rfere ...lth the mO\'l'ment of th",
secon dary tube ... lthln. To av oi d crooked"
drl .. ln g of tbe screws. t ...·o hole. large
e n o uKh t o " d m lt a lo ng t h in ec.......dr lv e r
s h OUld be d r ill ed at points eJt"clly o ppos ite t h e screw holes . All d im en sio n. o f
parts . re Cound on the seren d ra ..ln g ,
FlfrU .... 3.
The . Udlng rods s hou ld be of bra ll8 rod
Or t ubl nll'. % Inch In d iameter, thou lJh a
1I11 ll'htl y la r g e r e tee m a y be Ulle d If th is
is m o r e readily available. It Is bes t to
diame t er , r ee pec Uve ly .
*
---
Fig. I
A Summer Battery Suggestion
lows and you will n ot h "ve a n y t rou b le:
lst . drill a ll requ ired hoi.,. In t h .. t u be ;
Ind, win d the coli •• l'e<Iul red, leaving
loo pe fo r attachment o t tap Wlre8 ; 3r<1.
.......m ble tbe .. ... itch <:om p le te,. and t __
ten o r _Ider a g e n erous len cth o f tap
....Ire t o elleh e o nlaet . A lso m o unt th e t ....o
p ri mary b lndln l; po.. t s , c Oll uect lng o n e ~
a le a d to tbe " w itch ~ t a n d I he o ther to
" wtee t o be drawn thr o u&" h th e h o le ..ltb
In asse m b li n g the *"«ln d llT7. e:llce pt th a t
the dl e k C s b ould be In_rted after every·
thin g else l.Il I'lnlllbed . A Do v e l Id ea and
ODe tha t will Improve the a ppea rance o r
y our o ulftt b7 elimi n a ti ng aJl loose wi rIng co nals ta In t lUten lng the secondary
lenn lna l e n d. to th e s Ud ln g rodJI. This
Is be .. t done by d r il li n g a s mall hole In
each r od a n d _ lderl nr: the end of the
""Ir e In t o It. Care m ust be tak en to do
•
The stor age battery III oue u c lt o f tbe
Rad io set that cannot be dlsre p rded for
. n ,. enat lenJlh of time wnhout s u ite r Ing a reaetion. The necessi ty o f kee p in g
tb l8 partleular u n i t III lirst c l.... operatIng con d i ti o n Is ob viou!!l to anyone who
has u sed It 8JII a part ot the Rad io (lutnt .
The n e ees ..1t7 of rep lenl.hl n g the tnd l vtdua1 cell.. wt th dI s ti lled wa ter more
f r eq uently t h an u s u a l d urIn g t h e "u m mel'
mont h s I. due t o the fac t that ev.PO...•
lion ot t he wate r Is m uch more r llp ld , du~
to t h e ho t w e"ther. Fan a wh o o perate
the ir sets a ll yea r a rou n d w ill t1ud It
n e.," 11l111. ry to a d d d is tilled wate r a bout
o nl'e a w eek du ring the lIu m mer In s t <!'ad of
o n c e ev er y two o r thr ee week...
e ..e not hi ng bu t pure di Sti lled wate r In
r.
T",' ''' ',N4~ Y
tYIN IJ' '''. I N
litE"'. All"
r"''' '''''''LI
'HI S
•
•
IIAINfI;
TlJI_~_
_ ~#
3
I - - -- - -;J 4:f...
- - - --..j
1 - - - -- - --/2- - - - --
~-- Z£
--1
d rill th e ho leoJ t o receive the tube e In A
.. nd D .. lIl:"htly u ndersi ze (a boll t :1/1000
In ch .) Thl.. w ill make a fo r c e ftt a n d w i ll
"lI m lna l e t h e n e ces a lty o f usin g c~ 1oI1"n t
"r ..., t. IIcrflWe t o kflep t he ou t n t III p la ce. the othe r s . ~t h . draw a ll wtece tl'lrous h thl" at a po int on the rod whe re n O In It is alwa y.. u n w ll!e to m ake ln s trum enl ll the h o le fro m wit h in . Yo u will now be terference will be caueed with the free
~u Ih al th ey "li n n o t be t ake n a l'art If nb le to asse m bl e t he Call, u s in G" s l\e ll a c o r slidi n g o f thQ :n n or tube along th o r od.
5t h, The b est pl ac.. will b e found at a poin t
n<'~" ~~ary wit hou t c a us ing >lo m e t hi ng to g lu e 10 j o in the tube to t he s \>ooi.
l!r ~a k. Mlm y llmateU rlI a r e a ...t to d o t his lIol d er a ll w lr e a t o lh ... "ro l,er IUOl'S , n o t a b o u t 3/16 inc h out"lde o f th e " p ot a t
f orge tUn K" t hat t h e on e leud.ltl ~ to t h e w h ich a ruler lulu "'.H·OIll! t h e t ub e t uuc hell
tu tlull,· lRte ,' re g rel.
T he loole l! In II fin d A. on t he o t her h a n d , bl nrll ng po st ahould c on nec t with the far the rod ll. A fu-r you h a v e lInlsh.,d ""lIemend
of the win di n g . :\e" t. Casten Ih e t ube bUng the prlm.. ,·y t u b e II. littl e e Jtp e rl m en t800uld lie "orn e w h at o ver llbe to a llow eaay
10 t h e b lo cks E a n d F a n d faeten t o the Ing will IIh o w 110" "xact location w ith n o
" lid In " of the In n er tu be.
trou ble.
e e ee.
'1'..pp~ P rlmar7
Co11 . lD.4 n c:\ADce Valu ...
P u t t1Jl g See.onllal'J' T o..eth.1'
Caually th l8 t ype or t ra ns f orme r <;arrle.
Th e .lMlme p roeedure . h o u ld be Collowed
T h e p r lm.. r )' wl ndln " w ill be 3 Inches
lh e lAp e wneeee on the base b oard , which
n,ak" " a rU he r un s lgh ll)' job o n a ,,<,oun t
o f the m any wires . W ith a little ca re It
II! pollllib!e to p ut both " wi t ch es o n th e
" pool h l!1ldll, a nd rhus keep all t h e w irin g
r I G. 3
«>"~. Ied.
Tavp in l{ t h.. w i ndi ng Is u c ne In t he
a llual marm e r. tbat II<. a t ....ery tum where
• Iall I.. rflCl.u lred a little loop I" mad", In
th..... Ire and the Insulatio n ca .... fully
nped o lf . T h e wi res a .... tb.. n ..ol der "
10 the 1oQP8'.
The I,r lmary t op a_Itch s h o u ld be put
.. pool A In th.. posilion 8 h o w n .
n.",n .lona t o r locat ing It eJtaCtly h a v.,
'I bl'e n slvl'n because th e)' will depend
Ih.. Sl~ of switch w h ich you uee tae
.. lit. T he wiring Ilh o u ld be taj,lp<:d o n
rear s ide or t h e coli. wher.. the wire",
nol ..how. All tap wire" are the n
.. bed tosel her a n d bro u g ht In to the
NI
rou I'"h a hole dri lled In th e tu be
e totle l ae po!Islble t o the s h OUlder of
OIl" t ile
...,.
A
B
•
fl
D·£
}-/ ~/-l
~.1r--+- l
r.« . 2
C
-1Jn
F
.e,e:
~----I
t---JJ-+-J;~-----i
you r b lltt n y . Dolled wate r Is not d illtl lll'd
water, a n d te t he wo rst ki nd t o u"e In
thlll connect jcn. beca ulle t h e m iner a i lIa lt"!
a re precipitated and co ncen trate d llnd It
Is not Io n A' berore enough h a v e aec u m n _
lilted 'n the ba tt er y t o .. tart a n elect roly t ic a c t io n b e tw<!'£n t h e pla l es and t he
ml neu l ..anll.
T he r e a uIt III t h a i t h...
fram" w o r k oC the p lales Is IlllOn f'at.. n
"w a y .. n d lho b attery rulne.l. no n ot a tt .. m pt t o a d d a ny Rei d to th e lIo l u tlon , II"
It I" no t n ecesear j- a n d will undou bt edly
prove d e t rlrn e nt fll.-Geo.
H a n le y , Sa n
F r a n c i sc o, Ca l.
Straig htening Warped Dials
W arp ed compo"I Uon dia l .. a r e n OI Un'
com m o n on Radio ouUl tJI. Bucb d ial .. m a r
be liJted UP ILII g ood as n ..w If due r ae C>lutl o n and ca r e a re tak ..n. wh"n aHeml'lInK to IIt r a lg h t e n tbem o ut,
P~ed a"
Collo"" lI:
Ta ke the knob rrom t he face o f d ial
'I n d ..ubject Ihe latter to d r y heat. t ak ing
ea re n ol to craek o r blist e r t h e dl ~. or
me l t the .. urtsee.
All e r b e ing he.Hed.
t he dial I.. clamped \lig h tl y be twe.n two
.moo th. lJat board!! f or thr~ h o u r s or
mo re. T h la operation .... l\I g l"e a d ial a"
.. tralcbt a8 a ne w on"• •",,1 by eXHcl "l n"
a little caution, t hl" n"l)' be .... ~Ied sa
oft"n a " found de!!lrabl..._ P . J. C.
Car e of Vacuwn T ubes
" 'he n y o u h a nd l e th e \'a c UU", tuhe.. .. t
)'OUI' "ece h'el' great care .. h ou l<1 be e xe r·
cl eed th at t h c y arc net kno<:k~d nbout o r
that Ihe n !ll m e n t,. are broken. A 11<1"11 way
to ove ratll lhelle tu bes Is to keel ' the 11'1,,'11'
.lu st 10 little below the crl Uc a l f10Inl.
R A D 10
12
DIGES T
I L J. L: S T R A T E D
,
Radio Telephony for Amateurs and Beginners
Part VIII-Receivers and Loud Speakers
By Peter J. ,\1, Clute
'l'a1ephon . . .c . l.... o for Ba4.lo w ork.
Telephone rec e h elll f or l tad lo w o r lr.
IIhould be mu ch mo r e lIer".ltl ve tha n eonn a ry recel ver l/. ol ne.. n ad lo s lJ:"l!alll are
o rte n quito fa int. ellp.eclll. ll y tbos e f rom
dls U<nt .. iatlons,
Thes e r ece tv e r s are
usu a lly wound wit h f r om 1,000 to 1.500
ohm >! re stetance per Bing le r ecoh'er. It
Oerman " Ih"e t wi r e i ll ulled In wind in g t ho
bobbin " of Radio r e c llh' e fs, the COllt of
mak ing the reech'e. Ie grea tly reduce d.
.. In ee thl .. t ype of w ire h a MII mb eh hl gh e r
unit r e s is t a n c e th an cOI' p.e. wl t e of the
To ExplainT he followin g article by
P eter J. M . Clute is a conti nu ati on of h is series . Articles to come are :
IX. Crystal De tec tor R eceiving Sete.
X. V a c u u m Tube Receiving
IIa me ebe.
Sets.
XI.
Amplifien.
XII. U sf'ful I n forma tion.
L
a re i nferio r to meee "..o u nd ,.. lth
, I ceive
coP J>f!rs
r wire.
il E
TELEPH O:-:E
r ece h 'e rtl are,
IK'r ha p8. the n, o.llt Im portan t part
of a Rad io reeeh' lnl: eet.
The per.
form the nn sl ope r sHon for t he recepUon
of Radio s ignal s and enhance or d e t r a c t
from t h e \'alue of th o r ocelY ln g s ot . eeco rdln/f to the quality of th eir tone.
Tho te lephone rece iver c o ns is t s ..lisen·
tl al ly of a horseshoe magnet and a n armatu r e. u pon which III Im p r ells ed a ma l';neUe
fie ld d u e to tho cu r r-ent. nowln ll' In the
w in d i n g around the uer ecet.cc. n ..ft'r rlng
t o Fi gure 1. the mec hani cal f o rco ex erted
acrollS t he /fa p (lhe p ull of th .. e l e c t r o·
mli!:'nOlt UIKln the armaturel h i p roportio n .
al to the s q uare of t he Induction ac rO"8
the Ra p When a m a gne t ila b le body. s uc h
lUI Iron . la p ut In a magnetic fteld. t h e
n um ~r of line.. of foree If! In c N' a ltCtd :
the n um ber per IIQuare ~ntlme 'er o f a r ..a
Ia called the Ylnductl o n ."
If no eu rren t Is nowln .. t h ro uR.h the r.,.
eetvee ,.. Indln g . the re 1.11 a conll tant pu ll
T
f!Imm
C,,-':;';X,V,;pn
i 12.
ih
_.-
N(j.I: E.1SEh71AJ.$ VA
REceIVER
l?LEPHOI'fE
Howe ve r, IIlnc e t h , ee neut ve-
n e .... o f the "",-""h-e r d"'p<"n d ll. n ot dl ...ctl y
upon the TelI lslanl"e bu t on the number o f
tu r n ll of ",-Ire o n tue 11la l"n "lo. t e is read ily
ap Plln-nt that . German tllI ..., r w o u nd re -
T he d l sphra~m . of Rad io r~h'e rs are
t hi n ner t han thOlle of o rdinary recetver..
that It' s .. ener u Is r equi red t o se t the m
in v lb ratlon.
'rne ee is a ce r t a in li m it,
110
SUEVE -=t
Flt
CON r,ltCT3P/i'If'f(j
I£vEIf COlVr/l CT
I NSUlATI ON
fio.
J, JACK FOR
FIU I,.,!;
n I.EP/fOtt£
PL l/O
ho we \·e r. beyond ....hleh d ecrea sing the
t h k klle s a of the diaph racm also decre.....s
the sen"l tlv l t y o f t h e r ......h·e ra.
0,,0' type of recei ver ha s a lo n g I",rmanent rn&j;Il e t . bei ng m o ra t han a complete
erre te. "Ince t he end ll o\· e rla p. T h e ma g·
netic ci rcu it has ..omPllralh·ely little relu c t an" t' . h a \'ln g a d o u b le )\&th betw .... n
the po le - p Iece s ,
The a i r apac.. s a Tl! t h in
Rn d t he tlu x f r om the I'em,an en t m a Jrl\et
doell no t ha" e t o palls le n l: t h w lse t h r o u ll h
t he a rm atu r e .
Th",,,,e ....aJu res of the
m llll'n" tl c clrClllt fa vu r R IOtro ng tlux and
pe r m a nenc y oC ma l;"uUlUI thlO.
~h1:n. Arm a tll.r .
Main. :Part.
Tn th ll clectromagne t . tho t h in armature
III t he ma in part art ect <ou b y t ti e ene r gI zIn g
curr e nt. t he Iron 100'~ <Oll bein g thu ~ red uced 10 a minimum . T ho w indi ng Is con c('n trll t e d In a Illn !:" le 81K101 and it ll <'fr ee t
upon t h e a r mature III uU lbe<1 at both en d s
an d o n bot h aides at ellch end . T he t h in
m lca d ia phr a g m 1.11 ver y 1II;Cht a n d senal·
the 10 the Impul""a of t he .ar m a t uTl!.
T he dl a p h ra l;C1ll. armature. link and .. p rI ng
t ORe t h er ..-el gb o nl y a f r a c ti on of lhe
...·.llIht o f the cammOn .IItee l diaphrag m.
F1g ure % "howa a eert.aln t n >e of re"""I\'er that La dis tinguis hed for I..
m a t ehed ton e and plte"- p(W08esalnl;' a soft.
el('a r leone , which 1.11 a g r eat advantage fo r
lon lr d is t a n ce reel' lOtion. The d laphragm a
In t h e.... eeee tvcee are 0.006 In c h t~ck.
and the caps are pf ha rd r u b be r a nd Ilhaped
In >luch a man ner th a t t h e y li t cl o ~ly Rnd
f ee 1 qu ite comfo n a b le t o t h e eers, T he
ho bbln ll are w o und wit h Xo. 40 en alJl eled
I)ure cop pe r w ir e t o Ihe c prre e t num b <or
o f tu rn s. g ivin g lI. n appr oximate re.. lst_
a nce of 3.000 o hms to th " f!e t .
,\INSULATrol'f
PHONE CPn'DS1
due to t h e p <orma n ..nt hOTl.e shoe ma Jm e t.
~'hen a current Is tl owlnC In t he winding .
t he force pullin g the "Iaphra lfm toward
the magn<ot Is projKlrtlona l t o the s q uare
of the Induetlon . due to t he cu rrent flo w .
It la deslrahle that t he recei v e r diaphragm
"hall ,'Ibrat.. alway s <1lrect ly prppor t ion"l
to the current flpwln ll' In Ih e w indin g ...
11I0 II" t o r e p r od uce In au dlblo f orm til.,
var iati on s of th e c u rre n t r ..ceh ed .
The
gl'ealer the indu ctl on of t h e permane nt
m a gnet Is made. Qlher co ndi ti ons belo!:'
the sa m e . the greater w ill be the d la ·
t.8~,4SS TIP t
phragm a ll_pla cem ent fo r a g h en c u rren t
BRASS IJ()DY) HAlrD IrU6DE~
input In the r ecei ver Wlll d lo l('1J. 10 o t h e r
~ ~&V&
...·orde. the dia p h r a gm o f Ihe telep hone r eceh·..r Tl!peats the c UrrPnt \ 'a r la tl ona bu t
In a mp ll flffl form , lna am UCh as t he dla _
fi6.4. Two-Ci"culr TeL£PHQN£
"hn,,:m I.. a n e la" t1c body. It ha s a t e nd_
~ CORD TIP Pi.U4
eney to v ib ra t e at Ita natu r al freque ne y.
In m ost typea ot reeeree re, apecial at·
t h e latt er being larlr", ly d <o pend ent u pon
t b e ela .. Uclty of the m a t eri al of which ten tlon baa bee n pa id to th e pi tch as ....e ll
It I. mad e, T he current In put pf tbe r .. as to t he een sUh 'e ne ea In the d esig n ot
the rece ivers. Jt has bee n d ete r mined t hat
the human ear is m or e r e spo nah'e t o highe r - pi tc hed notea t h an to lowe r o ne.. , and
for thi s reason tbe"", r ec elvera are g i ven
a hI gh natural pe riod . brin g ing In ,..ea k
1Ilgn a la. clear ly a nd e t r o ngl y.
J ack .. .11114 JUn d inlr P o e t e.
Jllekll or bind ing pOllt ll for one pa ir o f
te le p h o ne r""clv ..r s li re I)r o v ld ed o n a ll
r ec<ol vln g s e t s . Fi gure 3 S110WS a Jilek In
which flU!. a. plu g fallt .. ned to the receh'e r
cord Ups. F i g u re 4 de pl ct a a two-circuit
plult. which can be u ..",d 'w lt h any s ta nd a rd m a k e p f j ack. As t he p l ug Is Ineert _
ed. It eon ne<:t s the 'phonell In Ilerle" with
t he ci rcu it auto matically.
A n ew p lu g has .......n d es igned t o an _er the needa oC the a mateur who d oea
not u"", .a loud. apeaker. T h is mUltl l'hone
p l u g ena bl e s o ne to In lltall f o ur o r Ie ....
.eta of phones w ith one plug and o ne
jack. I t ts construct"'" .110 tha t " ' hen two
Or mo ..........." h -e r a a re to be conn.,.,t"'" to
a r ..celvl ng ·..et. th.. y are Joined In se e tee,
liS t e" t a ha \'e aho wn t hat bett.. r result" are
pbl a ln",d than If t h e " honl's a re w ired In
mul tiple .
Ano ther commerclal multi phone aUach_
mt'nt lot m a rte u p eoml' lettl w ith four I'e t a
ee l Hr windin g" I" CO llwtall t In amlllitude of h.. "d"hon..., Thill d .. vtee may b.. u....d
b Ul varl ell In fr eq u ~ n ey , T he I!Teate..t In co u n..ctl on with a ny recelvl nl;C ~ e t b y
m o v e m e n t takes place wh .. n t he freq u.. uey alm ,.ly r lRm p lnll' o n r pf H' 1l rec e lvera I\rm _
Iffipr811sl'd I.s the IIam.. a . the nlltura l f r e. lyon the multlphone ,
Quency of the dlaphraCm .
Automatic Illamen t control jaclte pro-
"Id e a con ve nient li nd rapid mean a of upon t he turnt_ble ot thl!l m ach ln .. . To
a h Uli nl':" t he t e lepho n e. !rom one ,.wg e o f con n ec t the a ttac h m e nt It Is on ly neeeslImp ll llea tio n t o a not he r. T he)' a r e I'o .. oe- "''lTy to r e m p "e t he lIpoaker.bo::s: from the
n" cted a s to caU Ile t h e Insertion o f t he tone IIrm and re p la ce It with ttie a ttach m ent. The so u n d 1'lUJae.. from the r e ·
celv.. r t o tI,e to ne a r m of the machine.
and a loud-apeake r- III obtained at tew ex ·
I'enae, Jt can be uaod w ith o ne or m or-e
"tal;tlll o f ampllllcation.
·T h e r e I.. no d on bt but't hat broudca at
muslo I" a t It s b e..t when It 1>1 bea rd
throllgh
som e form of l o ud - " l><·a k <'r.
Radio 10ud~lIpeakna operat e on the II& me
Ilrlnl'ilOle all the phon o Kr a ph. Vibration s
of the diaphragm result In cor res pon d in g
BOu n d \·olnme. ""tlh Rad io. t h e v o l u m e
F14. 5 . ffL£PHOH£ cl"' CI( FQRDE7«TOH
of sou n d p r O/luced by a l o u d - s pea k in g d ",IIIfO AMPt.JF/£R CIRCUITS
...iee depe nds upo n the ene rg)" eeee tvee
t el epbone plug In a n y s tage to lI g b t o nly f rom t h e IntnBmlttl nll' ata tlo n .
l.ond _speakerll cannot be ",mployed di _
tb...... Il lame n ts req uired by that IItace o f
llm p li lica l ion . R emo" al o f t h e p lu g Itn+ r ect l y ,..lt h lIimp le c r y"la l rec e h·l nl: unl...
unl
",8.10 t he latter are 1000ated very n _ r to
m'!dlately .... tln gulah.,. a ll flla ment a and
.1I0 ...·a their r ellghtln g hy the me r e In _ th e broadcltlltl ng llta tlo n . A vacuum tube
..ertlon of the pl u g ....lthout adju!'1men t detector o u ut t l ucree ae s this dls tan ....
of the ftl ament rheoata t ll. This f eatnre
greatly In creasea the ulle f u l life o f the
vac uum tube a nd t he d ....ln on the filament
ba H tlr y hi r ed u ced t o a minimum.
T he
jack. lOhown In F igur ll 6, i s dellh:n ed fOI'
u .... between the d e t ec t or IIna ampllfler a na
su cc ees tve Il\a ges of Ilm pll ftca ll ou . exce pt
t he last st ep. w h tln a jack. lIu c h a . Ilhown
tn F i g u re 6. should be u .. ed. as t w o of
t he " p r inl!:s a r e not ne ce"ssry and are
o m itted In tb la jllck. fO<' t he last 8 t e p~
Lond B p _ k . n .
The l o ud - IlP<'.ak e r . One tylK' of w h le h III
" how n i n F i gure 7. ht \' Ir t ua lly t b e bai.-kbon e of llu cce8Sful Radiop ho ne rece p ti on .
W h en w earl n!; head rece tvere, o ne III apl
to bear t oo man y oC the d la turbances a nd
h o,..l" exlll Ung In the varlou ll e lreuU ...
eapeelally If the s lpala are brought u p
t cu d. H o....ever. with the Ipud_" ....aker In
operation . It III Renerally pos f!lble to hea r
Ih e v oice or m Ulll c 10ll d and clear a bo\'e
t he pa ras lUe 1I0und... and th la makes t he
H Rdloph "ne lien' Ice a ll th e more .po pula r
and e n j oyable .
As a genl'ral r ul e . a loud-sl>eaker will
no t work we ll on .. Imple receivin g IIHa.
Ho we ver . If the al l1'nal s re cet.... f,d In the
hea d· ..ct are exc.. ptlon all y lou d. It m ay bfl
po s a lb le to atta ch a loud -s p eaker t o Ih " " li g ht ly . bu t c v e n t h is me thod III not
adapted fo r g e n er a l uaage.
No ma tler
w h a t HoOT( o f r ec:el ve r l a u sed. whl're 111..
d llJtan ee from a trlln llmlttlng st a Uo n 1.11
n,ore than It fe w mlle a and a loud -Sl>eaklnl:
dev lee Is d" !Ilred . It will be Cound 11<. (' ....
ea ry t o neve an am l, UfI",r fo r sa tldllct ory reaults. An amplllle r I" a .... mbl....
lion of tube nnlla whi ch. " 'o r kJn l: t OKet h ·
er. can b uild up t he o ri g i na l enerf:Y of
t hi! 1"6e'e1\'lng an len na t<yat ",m . so all to be
au d ible.
Generally .peaking. ampUn.. r e
eons"' t pt o ne or two v acuum tubea "'lib
FtD. 6 , TEUPf/OI1E tlACK FOIl l/t S T
t h.. neee ....ary eon nec lln a; and co ntrol
ST.AO E OF AMPlIFICA TION
eq u ipme n t. An ampilner w Ith t w o t u bea
I.. called a t wo-Ilt age. t,..o-lltep or doub ler eceh'e rs. so lha t the sou n d may be made a talle am pli fie r. The re are generally I)romore au"lble by the eceuettc pro pe r t l..a vl d ed jack... fo r milkin g Instant an eo u ll
of t he horn . Ordinarily. a lo ud -s pe a k er I' luII: conn f "Upn to the nut o r . ec(oo d
m a y only be o i>"r" t e d by the u"., of lin llta~. all. d.....lrOld. thull regu laUng th e "01.t'!nl' lIti e r . O ne tYl"" o f lo ud - Ilpeak ln lt de- ume p f sound p r o d u('f d .
Vic e con s is t .. o f a "vedal hl gh_resl ..ta n..e
r ..c e tve e m OUn l l'd In a ba se over w h le h It
horn of scientific d c.. lgn. to gl\,e proper
acou "U es . Is mo unted.
It III In t e r .. stlng t o note how m any d c·
v lcea ha\'e be.. n Introduc.. d for use lUll
lo ud-s pea ke r ll In con n<oe tlon w ith the r eo
ceptlon of b r o lld ca llt pro grams.
F i g ure 8
d e p lcla o ne o f the new d e Vic es . w h leh
co nlliala of a al mple ca llt a lu mi nu m horn.
p rOVided ....lt b two S Tlna that termi nat e
In I'OCt rubber eaP8- T he o rdinary va lr
o f phones ciampa o v ..r the two a rm... eo
Ih at the sound mua t then paas UP throul:h
and be Itmplllled b y the horn, Xo Sheet
me lal Is ul'ed. lIQ t h a t the "tinny" sound
Is left out. Th e volume Is dou b led . heceuee the 80und f rom t w o head p h o n ea
a re b lended Into one power fu l t o ne.
:Ph on o. -ph 'l' TPe Lon4·SpeaJter .
A nother d e vice u t lllzell the tone cha m _
be r of the phon o graph . a s s ho w n In nil'Fi r · •
Thll IIlmp leli t
10ud_Bpeakln{:' devlco ..
make use of a IIln l: le t el e p h o ne r ec ei v e r
II. n d II, llpeola l horn . The>,e hornll are ,. rovld ed with " o tt rubber gallkets. or with
cl am\)... !'O that th e re~ula r r ece t ver may
be held in place wbll e the llound t r a v c lll
u p thro ugb the h o rn a n d are amp lltl ..d 110
11.11 to be a ud i bl e at a d is tance . The fact
th a t the!!e cev tcee may be ulW"d without
Rny altera tion r es pond s to the popular
f a ncy.
Regener ative Receiver T ri ck
A ~n"non ml ..take In a hOlPe- mad" TOge ntorath'e r ecd vl n g ou t fit Is t o r",'·"r lltl
t he Iee d e t o lh e plate coil. In this eeeettlon tile co il w ill n o t o" e,lIate. so Ihllt no
reae
n.. rllth'e ampllnea tlon te omatn..d.
Fir. 7
Ma n y nn "n,al",'r " '111 become dl ,.eo urh g.. ,1
IIr .. ~ .
It h" >1 b..e n ro n n" that the t o n o and dls..ard their t'o ll j Ulit fo r t hl .. HU lo
dllun ber o f a ny talkln", ma d.l ne I.. ,.u lt e m h. take. The t hl nl:' 10 d o Is t o e n auee
ra vo r"hl .. to tlw r~ l'r l)(tu ('t1 on o f It"dl .. p lat ", "oil lead .. I C the c irc u it due" not
mu,"lc and f!pcec h . On c of the phonell Is nlgenerate._Wliltllr A. Knight, lIudBOo.
attached to a novel holaer. ,..hleh rest. MUll.
www.americanradiohistory.com
RADI O
D I G EST
IL L U ST RATE D
13
Instructions for the Beginner
By llarry J. Ma rx
Radio Measuring Instruments
I E A CC C RAT E e l..t:trlea l control o f
t ranllm l H l n g lIeta by m .,1I.lI1I o f
a lcallnll t lOlCtrl cal Inlllrumt'ntll III
litml ,. ntahlbhM amon. ex~rl.. ncoNl 01>.."' Io r",. To HCure P<'"rtec t n .dllltlo;m t he
oloe.... l ot ot • t ranlOmlltlnl' flt_ U on u ses
.."",.lI nc l,. f.C'('\Inte In_' t umen ta as
1'1I1it... The no,-Iee oper_ IOU ot v aeuum
ttlt>to ~lvlng seta ~ .. m 10 be laboring
H e m ay. In a n effo rt t o be car.. rul of h ili
gu ess a t a low.. r li larnE-nl "oltlll:e
t han Is p r o per.
Th is will r .....nl t i n poo r
reduced ph one reception a nd I>r om p ll y th..
o pera tor pla ce)! the b lame o n the b r oa.d.
("a llllng BUlt!on o r u pon a n o t h e rw is e pe r_
r ~t1y g ood r ece h l ng se t.
The more cernm OD practice' s to o v e rhe at Ihe Alam.. nt
a n d f orce the tubt'a in an ..trOt l to U1: \1 ~
eeuer re s u lts, wh ich reduce s the li fe of
t he t ube withou t a compe nsat ing Incr ease
in reception.
A s small a n In "~.OIe ...
5 per c ent 10. tl lam e nt c u r r e n t a bove the
r . t ed ..... Iu .. a s d .... t.. rmlned h y t h e tube
ma nufaclu r .... Will , It ma i ntai ned., redu~
Ih e li t e o f the t ube t o on.. _f Qu r t h It. nor ·
mal U fe.
X etho4a of P'tl&men' ConnoL
Th ..re are t w o m eth<><l.lI ot tl lamen t <:o n.
t rol, th e ~·olt m .. t er "ontrol .nd th... m m et.. r conlrol. Wi th the v o l l m .. t er tbe ve u . I\"e a"T05S rue tl lame nl i... ma intai ned a t
II. certa in ~·. lue .
With the .mmete r t he
a m perage t hru the tl lamen t I.. malnt.ln&<!
a t a c ertai n v a lu e. T h e United S t a t u
na v y. In co-operaUo n w ith th e m a nu f a e _
t u rere ot tube a, a tter exten d ed. e xper l.
m e n ta l In~'e stl l\"atlQn'" ha " 1II d e t e rm lned
that t h e ~' o l ta ge life o f tu b e e Wllh veum ete r control Is three U m e e aa lo ng as
w ith a m m eter ct>n t rol. h enc e the v oltm eter
con tro l Is p",fe r able.
T h ere Is quite an ob~'lous r e e s o n t or
Ihl s d llf e ren c e In ilfe. A s th e tllament
burns It Is con stantly d ls ln t e g r a ll n g , dll e
t o t he high te m pera ture , a n d a s It w a llte s
away, It becom e s thinner an4 t h e elec tr ica l re s istan ce In crea s e s .
N ow It we
co ntinue to force t h e s a m e curre nt a s
m easure d b y an amme ter th rou gh the fil a men t , Fi g u re 4, th e t empe r a ture ccn etantly Inc r eaf!4's as time goes on du e t o t h e
c o rre"pond ln g
In c r e a s e
In
r e e te t e n c e .
T his hi g her t e m ve r s t n r e h a s t en s t h e dl ...•
Integra tion lind 800n resultll In Ihe b u r n ed
out tube.
I t , hO" 'ever, the ~'oltag"O III
mnl nlalned con"t ant w it h a Voltmeter
acr06" the tll"men t. Fi gure 6. the "urrent
th r o ugh t he filame nt d e c r ea s e " 0." t h e r ..sdatance lncrea ..es, a nd thl .. preve ntll t he
rlIame nt t empe r a ture reschln g d li n gerou ".
Iy hi gh va lues an d 1I0 pro lo ng... I h e IItc ot
the tub e .
In_It ub(, !I,
,u, d..r
&
m~Pllr('h ..n.
lon
In t hat the,.
d y Ih e n ......... lty o r In slrument conlrot,
T h.e u
o f Instr um.. nt COntro l Is desirable
Mit only a" a m ean e ot . m o r e c e rtain ad_
:Jl'Atmcnl bul beealll'" ... ltb <:erl.ln In s lru·
...tlle. d.ma..... to th.. tceee can b e pre'f'e n t ..d .nd t h .. ll te of Ih e lubefl ao greatly
pr.,lon«d Ihal t he ,..vl ug In the con o f
t llboo r.. n ......... ... 1lI AOOIl paS tor tbe ('Ost
of tltll ln atrumenl.
"
~,
--..;::
F lI'u ", 1
B r1lllAaoy No t E a ll1ly O a l1..e4.
W h e n et ecu-tc ll",h tla g wall In It.. Infa n c y _ Ihe lin " voltag.. waa adjullted by 01>,,"'noln g Ihe b ril li a n c y ot th" In c a nd e s c en t
lamp l<>cated In Ihe I>owe,. .. tatton, b u t
new t h a t commercial .. le"trlcal metum rl n j(
In ..trumcntll a r o aval1l1ble, " te p tn t c a
mode rn c e n tral s ta llon powe r p lant n n d
no te Ih e e labora t e IIwllchlJoard" wIth In trumen tll crowd e d sIde b y elde. Today
we w ou ld d ..c m It ab surd to u "o la mp btn _
UII"c y to g a uge Ih e ' ll n e v o lt a g e . T hi s III
,·x a " ll y th e m a n n er In w hic h 1Il0s t Badlo
r e ech'lng ae ts u .. lng vacu u m tu b c .. Ilre a dj ll ~ t ed t oo llY.
The tIIa rncnt r hOOlOtat S are
I<dj ll 8t ~d untll t h e fl lllm " n tlO apt'",a r to
b.a'· e the p r o pe r b rill ia ncy.
Be ca u s e of
Ih'" tac t t h a t t he nlament Is hi d d e n b ehi nd
t he p lllte iln d t h e I lIb n Is u.uall y m o u n t e d
eh l nd thllpilnd. vlelon contro l ot vacu um
IlIl...... Is even more difficult and "cc urat e
Ih l," In the ea se of c le ct r lc Ught circu its.
~I o ..t people kll ow tha t t h e lam p" enp_
l' I)' ln llC u s "'lIh llrrht are .....ted at about
II~ v olt " an d al eo ,..ha l will h appen If IIuch
IlImps ,,·....e connecwd a cro.... nil vcne.
Th e y would bu,.n Qut . It t h e line ;,'ollage
J" n ot maln tal n e" e rose t o 115 vcue and
drop" to Jl8Y t OO ~·o l l " . t h .. brilliancy p r o d u ct'd will not be . a tlarac l ory. Slmllarly
)'ou rnay !>urn o u t y o u r tubu or y o u may
f a ll to gel Ihe m o s t ~tfIcien t r esu lt ll It
y ...11 do 1I0t u se mM,aurlng Inll i ru m e n ta.
'l'lI.htI W orli:ll B . .t . t Ca na.tn ,, &10.•••
T be vacuu m t u be la a d elicate a n d lie n "Ith'e d" .. tee a n d It oP\" ratejl mOll t e tr ect·
h'c ly at dennl te " al u u of plat... vol ta ge
and tl lame n t temperatu r e . 'Without t he
u se o f In d icating eln trlca l me...urln g In Iltru mentll t h e operator can o nly g U" 811 at
the adJustm.. nt of t h e .... Impartant v a lu e ll.
MAl--.
Fl ,,," 2
m e nt ee nere te In essen UaI". o f I h ~ follow~
In g parta:
1. A perman e n t ma gn.. t ha.lng pole
pl~ce .. on t h e In Rlde o f the t ... o ~ :x treml tles
ea eho....n III ljI e lllu s t rl\t1on a n d ha~'llIg a
cy ll nd r lc.1 core Inse r t ed l>etween the
pole pl .....~ .. per mit ting a gap o f m i n im um
81&11I a u fflclen t 10 permit the c oli t o rota t e .
2. A coli, t h e movin g element, wound
In accor dance with the r equl re m enlll ot
th e In etr um enta and m o u n t ed In Jew ..1
b ..a r l ng.. " 0 all to rota te free ly In t h e ga p
betwe~n th<:\ pole plecea and cor e.
3. T ....o IIp rlnga ri g id ly attac hed to the
mO"ab le coil a bov e an d belo w , p rooJucl n g
a t o r q u e In " c ounter clock wi s e dire ctio n
e e.t et ee "erv ing to ca rry t h e current t rom
t h e e x ter n a l circu it t h r o u g h the coil.
~. A
poi n ter r i g id ly mounte d o n t h e
movable coil as shown In the illu stra tio n .
5. It nece s<'l8ry ,n e Xl ernal re s i stance
a s In t he calle of ttle voltmeter shown t
th e lef t of th e Ins t ru m en t i n the llIustratl on .
a o w M ete... :ln cUoa te o r M e e . ltn .
The sprln g ll produce a torque which
t e nd .. to kcc l> t he p o in t e r o n the z" ro of
I h e In st rum ent . thl" t o r q u e b e i n g In Ii.
c o un tc r c lQckw lse d i rection.
Th e p.. r rna ne n t m a gn e t produce", a magll" U" fiel d lJ.. l wHn Iho 1' 0 1" pIeces t h r Ollg h
Ih e c o r e . " 'h cn current flows In t h e c lr _
c ur t throu gh I he c oil. anot h ..... magnc tl c
flel<l I... e"lablhlhed s u r r o u n d i n g t h", coil
In ""oportl on t o the magnitude ot t h e
cu rren t. T h e two m a il'n e tl c fields are " 0
cOIlMtruc l e d th at the y r .. act and prod uc e
a torqu e In a c lock w ls c dl re ctlon. Th i s
torque l e n ,l ll to d ~ f1 ..c t t h e j>Ointer t oward ..
th c r ll:" h t . lin d when cou nt er bala n c ed b y
th e cou nter clock wise t orque of t h e
IIpr lnl:'lI. and co rrectly ca li brated, will On
a l,rOper scale, Ind i c ate v ol ts or ampereS'.
Fh::ure 3 IIllu s tra t e ll a direct cu r-ren t. fil _
ament lt m m"lsr o f t he tn'e d e s lgn c d t or
u ..... o n R a ,1I0 r e ce h 'l n g Or trana m lt tl n g
sel l!'.
F Ig ure 2 s howl a tll ament ~·oltmet..r of
IdenUcal t n '" w hleh has b een f o und 110
e s ".. n tl al f or tllamen t ccetee r.
F i' ..... ,
Vll1:a..l" the Inetramen te.
F iIV '" 5
Locat1o o. o f C r1 11c al Pointe ,
A"ide tr om the g r ea t A~'l ng In tube
lire . b y t h e u se o f p ro"",r v o ltm eter. lind
amm e te r ... a n Incre ase In t he eaae a n d ae"UTacy o f a dJust m e nt al"o r e llultll. The
characlerlstlc CUM'e" of ~'arious v a c u u m
tubea dllfer e~·e n IC ot the same t ",,,, and
man ufactured. b y the I18mll company, but
fer a n y Qne <If t h e s c tu bes, t h e critica l
value s m ay be obtained by e:x per l m c n l
once and f o r all. and at su b ef'quen t u"" It
la usua lly merely ne<'e~sary t o adj u fll t h e
l1lame nt to t h is best ,"a lu " and t h " n to
proceed w ith
the t u n i n g adJu"tmentlf
....hlch are tbus In d e pt ' nd e n t of luoo ed_
juslm"'nts. A n additiona l ~'ery Im po r t a n t
function ot the tllament " o lt m e te r I. that
It IIho ...." by Its Indlcatlon t h e con dltkln of
t he " A" baUer,. . "-hen no In !lt r u m e n tll
are u s ed , the only In d ica t i o n t hat t he
b a ll e r)' r equ ires rechar~lng Is when It
wlll no lo ng",r ope rat e t he t ubes. Th ill
la n o t o n l y ve ry Inj urio u s t o the b a tte r y ,
bllt It ma y be fou nd d e ad at a time w he n
m Ollt d e llired t or u lle .
T he p late v c tt m e t er, w hil e n o t aa Important on a r e ce i v ing eet a s th e tll am ent
v o ltmeter, Is ot great con v eni en c e a n d aslIlllt" mat erially In obtaI n ing t h e b e Mt r e" ults from the s e t . A gla nce a t the p late
vol tmet er wl1l sh o w whe t hcr o r n o t Ih"
" n " ba ttery Is r u n down or p roperl,. c o n neCled, a nd t h u s elimina t e t h o n e c e lll'l!t y
of h aving t o exam ine al l the c onn e ctio n "
On the set to I<>c ate t h e troub le.
COllatruotion o f M e t er• .
F i g u re 1 Ilhtstra tefl t he In t e rn al cOn _
"I ru cti o n o f a I", r m a n e n t magnct m o vehIe coIl In .. t r u m ",n t lIuch ,u, III u ..",d Itl di _
rect cu rre nt ' ·oltm c l er,., mllllvol lmet!!,...,
li. nl nle h· "~ an d m l ll la m""" l e r ll.
T h,' m o v " .
e1rtn lt.
By V8l7ln c the voltag~ on t he
tllamen l . the mapltude ot the curre n t
110wlng throuch th~ 1Ilement may bE' read
di rectly on the ammeter a n d by mean s o f
Ohm' . law, t h e r e si s tance of the nlam.. nt
m a y be com puted . By ~·a..,. l n g th" "B"
battery voltace tor v arious tllame nt vott agell , the n ature a n d magnitude o f the
plate current may be -,udled .
The vartoue uses of electrical measu r In K Inst ru lnen t .. tor use o n v acu n m tu1>£'''
a n d r e c e h 'ln l" .... Is are 11Iu I!t r a t ed In the
aCt'omp<l ny lng hook -up diagram ... An am_
meter may be tl!<ed fo r fila m e n t C'ODtrol
llII lIIu" lrated In F lll'Ure 4 or Ihe l're{.. rred
method , namely. vensee t e r c on trol. IS'
c le.r ly lIlu .. Ira t ed 10 F igu r e 6. ;S-o te t h a t
Ihe vet t meeee ill ct>n nnted. dlrH:tl y acro.....
the filame nt bet,..·ft n the tl lame n t r h eo..tat
and the t u be. l,''1gu re 5 "hows how t h e
mllllamme te r Is Inserted 10 t he plale errculL
A v ery IIlmple h ook~u p b y meanS ot
....hlc h It I" po""lble to l>ecome mQre ta.
mllia r with the ~'acuum t ube a n d t o learn
the uN-n tlal chaTllt't.. rl"tle... IS' shown In
FIKur e 7.
Thl" con"t"ts ot an ammeter
a nd II voltm"'te r In the filament ....treult,
lind a mllllamm.. ter- c on nected. In t he plat e
www.americanradiohistory.com
T h e Co m p l e tll- Bec elri:a.1" S e t .
A COm pl .. le ...~t c"n~l~tlol:: o f a d e tector
' u n l t a n d One .. ts"e o r IIm p Hl1catlQ n III
sho ... n In F ig u r e t . equ ipped w ith all mel e rs w hich are pract ica l for u ee In a ree..h·lng I.'I1'<:ull- I t Is not e ~''''ntlal tha t
t w o tllament ~'o ltme te ra be u""d as .. ho ....n
In Ih e dl e g ... m , bu t In a m anner s i m i la r
10 t h llt 11IIllltTated f or u " ln$: the plate
venmet er on enee e th e d etector or am_
plifyi n g plate, tb e tl la m e nt ~' o ltmeter may.
by m e a n s o f II .. wlt<:h. be u lk'd 10 Ind lr.at..
ei t h er the tl la m ..n t v o lt a !:"e o f t h e detector
tube o r the a m plifying tu l>e,
J". ad lo ta n" wne wl ..h to pro gre u with
t he de~'eloprnent of t h e sd e n ee o t Ute
Rad io t ~ l ", p h o n y ~e ptlon w ill be a m p ly
repaid t or Ihe lr ..lf nM.s It t h ..y u ll ll _
e"ery P<>.....l hle .."lcn lll1c m e lh<><l. ot tn ( Con tin ued On page Ii )
' - -- (v /-<Y<Fi e ' ,. .. ,
-
--'
R ADIO
14
D IGE ST IL L U STRAT ED
Panel Units for Your Receiving Sets
By Harry J. Ma rx
([)
liNT
"
"
Bi-
.,
B+
c
GRD
VJ\RIOCOUPLER 8: VAR IOMETf.R5
HON E.YCOM B COIL
TUNING PANEL
TUNI NG PANE.L.
PARTS FOR VARiOCOUPLER AND VARIOMETER TU NING PANEL
PARTS REQUIRED FOR HONEYCOMB COIL TUNING PANEL
1 P anel , 8",", 10"x ~ "
6 Bin d in g POl ti
No . I - P rimary honeycomb c o il
t
No.2-Primary variable "onde~er .0 0 t Mid.
No. 3-Secondary hon eycomb co il
No. 4-Secondary variable condenter .0 0 0 5 Mfd.
....
No.5-Tickle r b o n eyc:omh coil
No.6-Pla te circuit va ri a ble c o n den . ..r .0 0 0 2 5 Mid.
T h e tw o b in ding POt ti o n th e le ft hand l ide a re for d ... . e rial and
ground connection.. T be h o n e y co mb co il. a re aet in • t hree co il mou nt·
ing, p ermitting a vari able a d j u st m e n t. The pri mary c onde n ter, n umber 2,
pe"mit. finer _dju. t men t lor Wa Ve le n g th in d , e p rim ary ci re u it. In the
..m e way , the ".riable eundelUer, number 4 , control. the finer a d just men t
of proper wave le ngt h in t he ae c o n d a r y circ u it. The v a r iable c o n d e nn r,
nu m b er 6, awu to the ae na iti vity of the reg enerative feature in th;. hook
u p . The tw o binding poat.. in the upper r ight h and c Or ner a re for COn _
nection to the vacuu m tube detector unit, di r e ctly to the grid a n d poaitive
aide ol th e lilamen t battery. The two b in d in g p o ats betow ma rke d "Pla te "
and "8 +" a re for the regenerative c o n nectio n a n d connect t h e tickler co il
in ae r i". be tween the plate and the " B" battery.
I
HOOK-UP RD-42
In reply to a number of re'lue~ t s for
m ore h ook_u p dl a gram g, R ADIO D IG E ST
wllI InHe rt a t leas t one e vc r v w eek On t hi s
page, givIn g as man y detalls I\S possible
of the In strument" r equtred nnd expl nl n _
ing any 'll'ecia l f" ...t" r",,,,, Th e <l ing-rnm
n , D. _42 a ns w e rs a numbe r of requellts
to the Qu estio n nn d '-\nllwer Del.a r t men t
f o r a cl ro::u l t u sl m; a varl"eoup ler, varl .
ahle c ond e n ~e r n nd the u ",ua l detec tor veeuUm t u be wi t h Its rheostat , ba ttery, g r id
le" k nnu ~rhl con il" n s " r ,
T he ,'ar lahl e co nd e ns er In the prl m nry
I~ of the 43-plate t ype w it h capnelty of
,00 1 microfarad. a nd Is shun t ed ncr -cas t h e
pr im ary co il t o pe r mi t ne cura te t un ing.
The ~ rld conden~ "r has a ca pacity of ,0005
In lc ro rara d and the g r id le a k. a r es lHt ance
of ,~megohm, Th ese can be va r ied a n u
o t h er va lues subs tituted a s desired, The
vacuu m t ube Is the typical de tector' or
80ft tube type, The pla le elrc ul t req u i res
a 22 % vo lt " B " ba ttery with the u sual
nutatton that the pcetuve t ermin a l s hOli l d
1 Pane l,8"x l0"xH;"
6 Bindin g P o . ts
N o . I -Va r io cou pl er with tappe d p rim a ry
No .2-Primary variable c o n de ll.le r .001 Mfd..
No . 3 -..5econdary v aria ble con d ..n...r .000 5 Mfd..
No. 4-Grid vario met..r
No. S-Pla te va ri om..te r
The two bindi ng poat a On the left hand aid .. are for th e a er ia l and
g round c o n ne ctio n. Th... tapped .wit ch. on the primary of the variocoupl..r ,
a<lju ats the inductanc.. of the prima ry <:oil for Wa Ve le n gth cont rol. Th. ..
prima ry va r ia b le con den nr, n umber 2, contro l. the fin e r a dju.tme nt of th e
pri mary circuit. T h.. . econdary circ ui t;' roughly a djuated a n d rotation of
th e ...condary coil and the lin..r adjuatme nt is tak e n care of b y th.. _ co n d _
ary va r iabl.. conde n ae r , nu mber 3. Th e g rid variomeler, n umber 4, c on_
tro l. t h.e n o w of the curr..nt to th.. g r id of the vac u u m tube, whil.. the p late
variomet..r , numher 5, c o n trol. th e pla te curre nt now. Th e two binding
p olt. in t h.. upper r igh t hand COrner a re for conn..ction to the vacuum
t ube det..ctor unit direct ly to th e a r id a nd t h e poaitiv.. . id .. of t he filament
batt..ry. The two Lin d in g po.ts below marked " P la t e " a n d " B+ " are fo r
t h.. re g e n erative con nection and c on nect the pl at.. variometer in ae rie. betwe e n tb.e plate a n d the " S " b atte ry.
VACUVM TlJ 6 E
,OOOS MFD.
REC EIIIER.S
be On t he pla t t' si de o f Ih e circuit. The
r h eos tat Is of t he us u a l I )'pe controlllng
t he volta g e f rom t h e 6 vo lt " A" batter)'
t o the mam ..nt of the vacuum tu be.
T h hl ct rc u u Is a si mple one t o t une,
a nd becau se t he u s ual \'arlometer s In t he
gr id _and plate ctrc u tt have b...en om lttetl,
It avoids th e pos sib ili ty o f di fficu lt tuni ng
ooerat to n. Thill circui t. of cGurae, Is of
the non- rt'gcn eraU ve ty pe .
Grid Plays Important Part
. 5 M£CiOHM
RHEOS TAT
22!V
L..-...._ _--+----j
RD-42
www.americanradiohistory.com
I1I1I111 t----l
T h e pa r t that the g r id plays In the OP'"
eratl o n of the Va CUUm t ube. In co m m on
u se on n a dlo r ec eiv e rs, Is mO:'lt ln terCllt In!,:, T hi s Is the e le c t r od e t h a t d e li v er s
t he pu h<at lo ns o f t he R a d io wa"e s whic h
arc r ece iv ed b y the an tenna t o the "B"
ba tt e ry circu it.
The cur rent f r o m t h e
" R" ba tte ry paases bet ween fi la m en t an d
pl a te t h"ough t he g r lu Itself,
T he c-r ld add s to or subtracts fro m the
flow of electro ns m o vi n g f r o m the fil a _
ment to the plate. a n d t hu s eont ro ls t he
l,ho n Nl On t he "B" ba ttery ci rcuit s O tha t
t he phone d iaph r a g ms g h 'e the c or r es pon ding Signals to t h os e r-ece tv ..d b)' th e
aeri al circuit,
RADI O D I GES T ILL U ST R ATED
15
Questions and Answers
~ u ud lulltlJ.lat.! OIl
I haVII been a r eader ot the RADI O DI·
I L L U ST RAT ED almoat f rom t he
luue of It , and bave obtained much
alQ.il.L le In formnUo n rega rding Ra di o
rrom. but I a m ,.UIl at Il lOll" 10 uet
diritltnd sc me phaus ot t he s ubject .
am Inl!tallln g 0. Radio set In o ur place
ot bu" ln es" an d I wo uld t ne rerc-e appreC!" t<l a ny Infon naUon yo u can giv e m e In
regard t o t he f ollow i ng q ue.'ltl o n a 1 am
&liking you :
1. wru a wate r meter In the water pipe
Une t hat Is u"ed for the eer vtce gro und
aJt..et t he o peration of a ..et ?
2. 1>1 It perm l" s lble to run th e servi ce
grou nd wi r e th rough t h e 11001' ot the room
t o get at a wat er pipe li ne to be used
tor ser vi ce g r ound?
3. In the diagram herewith cou l d t h e
serv ice ground be "a rne w a t er pipe as u" ed
for 1lg h t nl.llg ground ?
... Would the arrangemen t d r a wn In (3 )
Ustactor)' ? Tll a t Is, wcutu It be Ilah
\pe a lIwl t ch &.8 s hown ?
5. Will a motion pictu re mncn tne u nde r
tbe roo f of th e buildin g o n which the aeria l
III er ~('\~ affec t th e Had lo ....t w h ile m oo'
tlon. picture m ac hine III Iii o peratlon?
S. Can the "B r a ch" va cu¥ iti l ig h t n In g
a rru t ..r be pl a ced InSide
t h e build.
In..?
,
7. Can the aerial be g rounded from one
..nd . using a "Brach" arrelliter, and the
lea d·i " for set be t aken fr<lm other e nd
If a s wHeh t s Inllerted In lea d-I n to tn etru'nent?
• . What kind of II. set wo uld y o u' reccmme"d f or g h ' lng co ncerts Or en t ertatn menta In .. motio n pictu re t h H .tre to r u s e
with a lo ud ..peaker ?
t. Would 1\ I\et usln !\" t wo stages of Rad io
f rNluenc)' a m pllllcatl on . em plo y in g the f a_
mllla r varlometer, var!ocoupler combi na_
tion for tuning. be s atl .'lf acto ry for t h e pu r_
potle outUned In (8 ) If a n aer ial ot the t nverted '"L" t ype Is u lled tn ar ead of u sing
hone yco mb ee n e for tunin g ?
to. It t he arr angemen t In ( 1) te used,
co uld t "·0 Ret. of Instrnmentll be operated
from t he ~llms a eri al (at th e same time)
In diagram here ?
*'
or
RADIO INSTRUMENTS
(CORl lnued fro m pa g e 13)
creas ln lt the efficiency of t he ir recdivlng
Nta. Year", o f Uldl o u" aclc.ntlfic re "ea,·ch
by the most cllI,able m en In the profe s"Io n have rE>aulte d In the verfectlon o f
th e mod~ rn h ,dlcaUn g electrical m ell llur_
Iftll" 1,,"lr\lJn~ ntll and It III " a t u r nl that a
P'lr so" u ~ l n g e lect r ic it y In any forlll
shou ld .. va.1l ntmeerr ot thelr achi eve-
11. W o u ld th e arrllngo:-ment In 410 ) give ad" I"e a. s i ngl e w tr e 100 f"et long o r II. t h e f o ll o w in g ques t i ons:
I encr cee se1r.....UaCa ctory results or wc utu It b e better 'i5 f oot two w ire e menn a.
a d d re ,.s e d s t a mped enve lope.
to g ro un d secon d Ins tr u me n t to t be IIs m !!
U n der fa vo rable condI110" " ",'hat w ou ld
Hav in g etlen I n you r la.'l t number of a
w ater p lpo
grou nde <l?
to
whi ch
t he
ll rst
lie !
18 be t he greau,ollt d h. ta n ce, In y ou r .. sllmlt_
uce, that 1 o u g ht to be able t o re_
12. Cou ld b ot h set'; be opera te d a t once? c ei ve b r oa d ca st programs wltb the above
A._I. T h e g r o u nd cQ.ml!"l!on shoul d b e "et?
mad e dllte r ent on t he Incoming p ipe be fore
A.-YOUl' ho ok_up Is all r lgllt. We would
t h e w ate r meter is Inserted, BS the w ater advise the " Ingle Wire aer ial.
meter lIomctlme!l ollera a f aulty connec- dillon", About 20 0 miles.
tlon.
2. Yell, If p roperly ..n ..l o lled In poroelIt o vl n.g the set
(7 00) GWV
lai n Jne ulatlo n.
3. The ll ght nlng g r o u n d sh 'lUld be a
I tak e.- 1hll! opportunity 01' accepting
s e p a r a t e outside ground.
vc u r off er of a ss l stJlnc e to t h e r ea d er s of
4. Yes.
RAD IO D I GE S T .
A lth o u g h 1 have a U
5. Not v cry a pt to. T he arC may ca u ee p u b ll ca tl on a Of the RADI O D IG EST t o
date, I reu so fnr to find a hook.up t h nt
so me In terference.
G. Und erw r iter r ules e re t e th a t 1t s hou ld wi lt r eue ve m e of m y t r OUbl es.
be placed Qu t s lde .
The set co nsh.ts of the f o no v.-In g: On e
1. Not adv is a b le .
v a r tocou pter , t wo ,·arlometer s , o ne var iable
8. nege ne rallve s et with two " te ps of conden se r, one de tector bUlb, t wo am pli fie r
nad lo a nd tw o o f a udio f requen cy. Yo u bu l bs , t h ree s oc ke ts and rheosla t s, two
ma}' need power ampllficatlon In a dd ition tran s formers, one "A" battery, two " B"
to w o r k loud speaker.
ball cr l",s, o ne gri d l ea k and conde nser ,
9. Ye ,,: b u t It p OBl'lbhl would recommend p h on e" .
•
both arrangements with SWi t c he s t o cut 1n
1 m ight "ay t hat 1 had this set h o; k ed
eith er t ype.
up so ma t the co n cert l! Came In lo u d
10. No.
enough to "knock vour ear o tr," bU1 tilE>
U. N o.
aarne hook -up f all en me en tl rel ~ when 1
12. N o.
t oo k th e aet to Fli nt, 2.l Ich ., a d f"ta nce o f
Book_up.
abo
u t s l xt~··fl ve m ll el! tro m the D e l r o lt
(6 08) J G
Please a d vf s e m e cap a cJ tlll8 o f each b roadcas ts. A180 I am u na b le to get a ny.
v a.r labl e cond enscr Indica t ed In Hoo k-up thing o ther than D e troit .
I au r a w ill appre cta te a ny In f orma ti o n
R. D. 22 sheet 7. Al so w it h 360 wav e
length d uo -la t e r al con, wo ul d th e b ook·up H' U ca n g lV8 me, r a mer 1 s hOUld say
"
h
elp."
be capable of aner tuning anll r ece pt io n
A .- Tn 1asue No. 12' are fou nd t h ree
than Hook_up R. D. 23?
A.-Th e 2~o nden lle", f e r R. D. 2Z IIho uld hook_up,,_ t wo o f whlc h will no d oubt f ul _
Ilave the capac ity ot .00 05 m fd.
Yo u till Your r-equfr -e m enta , Your letter dOell
wlll lin d lltt le Or no d l lt ere nce ·between the n ot state w be th er 3·0U ba"e Rad io o r audio
hook-Ups n. D. 22 and 23. The baUer y frequ~n ("y t ra n do r mers. T h e l oca ti on of
potentio m e ter In ll. D . 23 111 ln 1ended to F lin t , M ich.• may be a n un favora bl e one.
ocst 8lgnals. T h ebone yco m b colli n R. D . I am ra t her In clined t o believe, h owe'·er.
22 IlJ simply a. l oa d in g coil, to be ug ed that In s h lf ll ng y o u r a p pa r a t u8 y o u made
where a sma U an t e n n a. IlJ m e . o nl y k ind ec m e c ha n ge Or made s o m e b r eak In con_
a.' ·lj.llable, t here by g i vi ng t he r eq u i re d necrtcne t ha t a trected Yo Ur rece ptio n. A dd
a counlerp-olse gro und If y ou a re s u rwa ve leng th.
r o u nd ed b y san dy soli .
D ouble Aerial
(623 ) NMCH
VlU1ocoupler azr.d Varlom.ter
I ha ve a c hance t o save mys elf a l ot
of Wor k an d expen811 In p u t tlng u p a da n dy ( 638 ) B R
I am r eadi ng )·our RADIO DIGEST a nd
aer Ial pro Vided I am not goi ng to ge t In
t r o u bl e. T h ere Is a man Uvlllg a b o u t 3 QO think It I" flne. I will acce pt your l uvita·
tl
o
n and a llk yeu a Que 8Uon ;
10 32 5 f eet a way t ro m m e lind his hou s e 1.'1
1. I have a lun ing coil, c rJ ·stal detector,
loca t ed approltimately fiO f ee t blgher than
m in e.
In addilion to Ihls lie h a s a 60 fixed condenser, lind a hea d SE>t w ou nd to
f oo l lIag pole. B y ru n n in g a n a e ri a l fro m th r ee thousand ohms. H o w m an)' met er s
th is pa le t o oue (l en gt h ' 20 t o 22 tee t ) on ca n 1 hea r ? If I use load ing co lis In
t op o t -my ho us e and Ins ula ting % wa y s er ie s , can I h ear the powerfUl G overnmen t
betwe en t h e hou se s, we w oufd both ltavc e ta no ns r
2. W hich 1.'1 be st, n var t occ u pt er o r a
a lll,roxima lel y I SO fe H ~ a..r lal In<,l ud ln g
t h e lea d-I n w ire. .A1 t he mid dl e Il'e wJ r e va r lo m cter? •
3.
Cou ld you s end m e t he plan" t o r m ak_
w o u ld b e close 10 1 00 f " ct Ili g h. B u t -we
have to cro" " a street w h ere th e r e Is " Ing a I;ood R ad io set?
4. \ That is th e lowest aer ia l 1 cou ld
1roll <-y l in... o f 6 00 volt.. DC b u t li8
s tat ed a b ov e we w ould be f r o m 5Q t o 60 have !lnd get good r es ul b ?
A.
-I. Yo u ("annot li en!" m e ters a s )·ou
fe "t o ve r t he s e wires li t Ie",,!.. "-'oul d
)·ou ki ndly sdvl se me regarding t his a t state. It wcr-ka 011 a w ave len gth range
)·our ea r l l.."t ..o n ve n len ce. I n t h<- m ean, exnreeeed In metes-a . Ye s, lo a d ca lls will
t i me we are arra ng ing to get pe r-rctsstou do It.
2. You d o no t g i ve sutllcle n t d a ta t o r
rrcm the ctt y and a l ..o from prope r t y
us t o t ell ju" t w h a t r an ge r c u r Ile 1 will
own er s to cr os s 1Jll s s tr ee t .
ha
\·e. A " "rlocotipl er Is b est.
A.-Tho:! a .. rlal will he fine ! K ee p . an
3. The R AD IO D I G E S T In t h E> "How 10
o p...n s !>ItCtl at t h e ce nler of about a f eet ~[ake
" ("ol u mn" Is al w a ys g iving you In .
by us lu g 2 Inllu la to r " th ere. Dl r ..ct c ur- f o r m a Uon o n makln ll" Jla rls of seLs.
rent trolle y wire . w HI n o t a ffee t )·our re4.
Yo
u r ncr ls i s h ou ld lJe a t leaBt 50 feet
caption, be s id es )·ou arc at r ig h t a ngles
a n d ta r enou gh aw ay. You'll ma k e c ut h Igh. Get th e he ~t he lll'1l1 y ou ean.
"T"' and "L" 'rype A eria l .
all r ig h t.
(6 79) HG2.f
'1'00 Mueh E a p ected.
1 have .. few q ues ti o ns to aak you. ta t :
(67n ARF
\ Vh lch a er ia l I,,· b " s t , One tapped In th e
y ou k i nd l y lI.d\"f..e i f an R _3 M a g. middl e o r a t t ile end? 2nd: )"1lI a 100'.e
navox l oud sve a~er, connec ted to a s!lort couT,l er Jn c r ease til e receiv in g ra nge of a
Wsve r eg ene r a tl vc rece h ·..r and t wo s t a g e <,rysta l e c t ?
If .'10, a bou t how ma n y
aud io trequen..y lO m vll tl er w o u ld nIce l. e mll"lI!
mus ic f o r the la r g e b,·oadca:;tlng st a ti ons,
A-tat. The aer ia l t apped On t he en d.
a t a d i s ta nce ot 0,", t ll o u s s n d mil es, a nd
2n d. It will not Incr ease t he range In
a m pli f y the 1I0und l oud eno ug h t o be mlle ll, but w ill Increase the tun in g r an g e.
heard a t t ho far end of a r oo m , one h u n .
Statle
dre<J fe et 10llg and for t) · fin' f eet w id e ?
( 685) R~
The antenna I in l end u sing w l1l b e
I n t h e Mil)· 2'i iSSUE> of t he R ADIO DI.
one w Ire, "e ve n str Rnd ... flft}· teet hi gh GE ST you flult\l 8lled an arti c le on a n ew
and about one hundre d a nd s l lt ty te et dev ice 10 ellmla u e Ilta llc dur ing t h e BUm_
m er .
lo n g.
A- N o. Tnllert s o m e Radio f requ ency
Ca n you advtse m e when th is new device
a m " ll flca Uo n. \ Vh y a dd s even st ran ds t o wlll be on 1hc ma rk e t a nd the apprOXimate
seiling prlc s ?
yo ur aerial wh.m t w o are sufficient ?
A .-'\Vr lt e Dr. LOUis Cohen, Conll ulling
" Which ?"
(262) ENC
Engine er , Sign al Co r ps . U . S . A ., W a sh·
T a m a"s e m b ll n c- a Radio r e cE> I\"l ng se1 Ingt on , D . C .
t or th e r cce pt lo n of mus ic and speec h a n d
wcum like t o know If t h o cn clo" ed dla_ (629 ) en
R"!"lI. m I" the mosl effec tl ve h o ok · u p for t ile
H a v in g .'Ieen YOU r r t'l':t u l'" t to Wl"lte to
m en-ument a I have o rdered. WOUld vou you when troubl ed, J w i s h yO U to 8-Ilwwe r
b roadcasti ng sta Uon In Sprlngne ld, I II. :
1. W OUld 1 be n b le t o re<:.elv e t h l" s ta_
tion w i t h 10 0-f oo t ae r ia l, luos e cDll pler,
Cr )' Btal detector, variable COndtlnller, fi xed
co n denacr and :,OOO-oh m phon es? I live
about 26 m ile s f r o m Springfield.
2. Also, w ho operates this e1aU o n 7
\\o'h at a.r e the hOUTa o f t r a n e m lt Ung ?
W ha t w ave length ? How f a r ca n t h l!!
s t atio n broa dca!!t?
A.-I. You lIhould be a bl e t o do s o.
2. WDAC 1" the call : aao meters Is It s
w a ve I"n gth. Ra llg e a nd program of o p _
e ra ting h ou r s wUl be g iven In R A DI O D I .
GES T all soon as report is r ecei ved.
C rys h.l D et ector
(683 ) J LC
'VIll you pl ea se a d vise m e If t he enclOSE>d h oo k·u p (or a c r~·slal detecto r reo
ee lv l ng set i s correct and, If n o t , give the
r i g h t onc?
1 ha f'n a J OVE detect o r a nd a U unl ock
tr pe 5 6, 3,000 ohms h e a d set !tnd a .01
m td. tlxed condenser.
A .-The en e lo~ ed hook· u p h a ll bee n
changed. I f )·o ur fixed cond en,." r Is .0 1
m fd., 1 w o ul'\. sugges t th a t YO U <,ha nge II
f o r o ne w Jth .001 m fd. capaclly .
On C:OU Ca.1cuI aUona
( 6 99) AC.J
A fter deter mi ni ng With the alII ot yo ur
In s truc ti ons t he In d uctance my t uner mU llt
have t o tune fo r a g iv en wave l en g t h , h ow
a m 1 t o k.now t ha t I sho ul d nile No. 2 ~
wtre On prl m a r )' a n d No. 26 on seconda ry?
A l so, h oW Un I t o k now t h a t I ..h ould u "e
20 tu rns on prlmar)' and 22 tu rn s On sec·
ondar y?
' T h eBe are qUe-8t1ons tha t may s eem E>l e.
me ntll.n" t o you b u t the y give m e rc.. 1 co n .
ce rn. 1 can eee )'o u r f or mu is clea rl y a nd
can ap pl y It In solullons, b ut , n ot know .
Ing w h y 1 Sh0111d select t hese nu mbers ,
teaves a lin k o u t of m y c ba tn ot t llo u g h t .
AlllO, wlll you pleaa e give m e a bet t e r
ex pl ana.uon of lable 3?
A.- I t Is m erel y a questio n of j u d g m ent
and e x perl e n ~ e tllat gover ns the d e cl ~ lon
011 wna t. Wir e to u ae f or pr imary and o;"c_
o ndar )' wl ndln gll of an~' tu n ing enpara t u e,
As a rule. the ljecondary winding ueee It
g.au g e or two sma tter than th e p r i m a r y.
): o u cannot tell b" fo rehan d how many
t u r ns a r e r equired In l'!the" prl mal·Y o r
secondar-y.
An approximate n u m " t· r of
t ur us Is assu med , and th e valu e au"set.
t u t " d in the for m u iu . It the rE>.'Iutt Is t o o
Ia r-ge or too s mall, a IlCW value for a num be r of t u r n s ~hould b ll fis"u m oo and ca lc u _
l ati o n s r ec heck ed. Thl ~ mu a t he r " lle ut ell
un tIl Ihe inductance vatu e Check >! u p w I th
the reqUired amo unt. F r o m expe rtrnon e,
It hall. b l'en foun d 1hat d ll'rE>rent l en gth "
a n d df ameter-s of w lndlng8 give "light
va r ia tio ns In th e r o rmut a . T h E>88 varia .
Ilous a r e Ilc:cou nted fo r by 1h e correction
fa.c t o r "K." Table 3 glV ~ thl.'l corre ction
factor, ta ki n g In to con llideration tbe dltr"r _
ent windi ngs, leng1h a nd e ta m e t er of the
coli.
"'ill
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