Belt Valley times. [volume] (Armington, Mont.) 1894-1977, 1925-10-22
BY SIDNEY {. FlNKELsTElN.
n RadIo World.


in Radio World.
For the fan who has made many
sets some variations on the accepted
themes are very inviting. hence two
circuits are presented that offer en-
couragement 10 those who like 70 work
out solutions from suggested data.
The FIRST circuit Gig II consists Of
q stage OF tuned radlo-frequency am
pllfcation. with it's two tubes connect
ed In parallel. regeneratiye detector.
the first stage Of .audlo redexed In the
allel-connected tubes, the second
stage Of audio being solo"
The other circuit Gig. p, using the
same principle, makes the last audIo
stage the renexed one. The parallel
connection OF the tubes in the redexed
stage Is retained.
Only one reason for connecting tubes
In parallel may be adyanced-t0 make
them share equally the load of the
stage In which they are connected.
With RE- application so popular
often there Is too much Of 1t. so that
distortion arises from RI causes, no
less than from an overburden Of audio
current
Two Audlo Stages Employed.
AS the test is one for reducing the
overload. Il any. two audIo stages must
be employed. Some may ind that the
hook-ups as suggested viii improve the
quality OF reception. At least expert
mentors may establish to their own
satisfaction which Of the two methods.
II either, gives them better results in
quality. and possibly even greater vol
ume than obtained heretofore. when
the four tubes were hooked up simply
Ip straight fashion.
Constructors who have test boards
will find the circuits very interesting
subjects Of experiment. The change
Involved In making one Into the other
Is slight.
The set In point Of distance getting.
win not accomplish any more than the
regulation hook-up. But II a fan Is
troubled with distorted reception. In
stead Of introducing reslstances across
audio transformers. or condensers that
cut down the volume. he may try |
either or both OF the methods outlined.
and see II he cannot get very clear re- I
ception without any reduction in
volume.
Liz Is radlO-frequency transform
er and CT Is a variable condenser OF
correct capacity to tune the secondary
T.2 throughout the band OF broadcast
Ing. L8L,4I5 Is q 3-circuit tuning coil
In which Is Is the ticker CO tunea
Ia CO Ia bypass condenser. about
00l mfd.. So Is C5. R4 IL grid leak,
about megohms,
the tubes are numbered /. 2, 3 and
4 In effect tubes and 2 represent
only one stage In either diagram. The
Input Is TO the two grids and the out
put Is from the two plates. These two
tubes should be OF the same type.
TIVE Tubes In Parallel.
me RF load on the tube 10 partly
determined by the mumber OF turns on
he primary L9. Generally speaking.
ne lesser the lnducsance and coupling.
he lesser the tendency TO overload
But unless one has ratio OF at 4-to-1
here may be losses. / q. insufiiciency
ransfer OF energy. Assuming. there
ore, one has the type OF windings
most commonly used. where thar ratio
q used, or something near Il. there
nay be sEill quite tendency 10 ASK
90 much an work oe the armt tube.
7encs we viii MSS two tubes in parallel
or accomplishing only the same guar
ltasava results New. net 20 reqalFU
he nee o1 any more Tubes than would
he standard hook-mp. we mast resort
d Fwzamxfm@. TMmt 0fsam causes aEfa-
ufglAm nuxf n TIA reflexlna isn't =
araaal wirsmg Job. with proper regard
ar pnazesam mnt length OF leads. ali at-
snzpsn 10 attain improved results are
lmeaf cmr1min 20 fail Hence be care
II az vvar r@kex work.
Mum. khe sast audlo tube handles the
navfer ausaze load Maybe thai Is tire
"a fssaf should be reelected. since the
Ianaae mra TO be delivered lmto ehe
armslal.conn@cted stage. which Il II
are able to handle ehem best
nj ah@ ewp8xsmenfeE may ana that
ID anaza laasz b. not the tronhlesoma Z
nA 4ss8 radio load having been
safmss Satisfactorily between khe twa
sN@a Il AAzs III, ths rsiAex IDEA nsav
/ esnho@zaesz @esnsg Cor the ebiees 81
assasssshs alH4 mxAFa fmsses and moa for q
H. s4sge Mma eomdzesoN asa ~ - 4