New-York tribune., 1922-08-20
First Aid for the Radio Fan
Why Turns on Loop Must Be Spaced;
Eliminating the Cracking Noises;
Using the Rotor Coil as Ticker
Tuning the Super Regeneration

Tuning the Super-Regenerator
Question: Re super-regenera circuit.
! Ny homemade loop aerial has twelve
turns of No. Is cotton-covered wire, spaced
about three-eighths inch apart, and each
side OF the square which is formed by the
outside wire Of the spiral measures feet
Q Inches. Would the results obtained by a
larger loop be in proportion To the in
creased size of the frame? q How inn
portant ta It 10 have all of the aerial wires
absolutely taut and eqaidistant from one
another ana in the same plaee? II this IS
hard TO obtain with No is wire. should I
pge say. No. 20 or even smaller wire?
Would heavier wire be preferable? 3. My
aerial wires are beiu.s held In place by
being stretched over small tacks which
are driven into the wooden frame. Does
the metal In these tacks have any effect
so long aa ] take are that no two tacSs
actually torch one another? 4, | am re-
Winding my vario coupler. which Is Of the
common so degree type The primary
now has hfty-eiEft turns OF No. 22 single
eotton-ceysred wire and IS tapped at each
OF the iirst ten sturns aud then at the
twentieth, thirtieth, fortieth, Gfiieth and
fftyeighth turns Would it be better to
nave, cay, eighty turns of No. q single
cotton covered wire instead? 5. Ally rotor
has only Is inches of available winding
space. so how would 1t be il wound ii
with ten turns Of No. 80 enaineled wire 7
Would tnat rsesn Hat the primary shoula
De wound With the same size wire and
eighty turns? Does the finer wire have
any influence on the results obtained in
the set? q. Would II be possible to arr
range this SGT to receive Arlington time
si@nais. ard how would go about Il with
out fewindlug the primary of lily Vario-
coupler and without employing bank wind
ing even e Tie tube has TO be longer? ?
what wire wonld you advise tsame as on
prruary) and how mary turns and taps !?
4. Would be able TO hear Aaiiagton with
this two-tube set? ain aware that the
ampllfcaticn is much less with the lorger
@ave-lengtf1s. Are equally sootlseesu1ts
obtained with reyslnding the roteraof the
YaiHo-coupler, as with Inserting d vari-
pineter into the circuit and leaving the
ordinary number of turns on tne rotor2
the primary OF the vario-coupler is in
series or parallel with the aerial ana pri-
mary conderserP l have seen diagrams
either WAY 10 Could you describe to me.
step py slep. how should proceed to tune
"a Euper-regenerative set? Is the loudness
OF the whistle any guide? Should be abla
80 near the whistle and the oscillation Of
the first tube at the same tinaeP no njaff
dc | have the potentioncter set AZ tbs
half way position? What Should look
Tor IN varying the taps OF the vario-
coupler rinlary--ioudcst oscillations? H.
have sorne dry cell batteries such aa are
used Tor bell circuits and want to use
these for the &C. batteries What ID the
voltage of one Of these dry cell batteries 2
a., NJ q
Answer. The loop aerial you have
made will be quite all right, and the
size does not need to be increased il
any way z. 1t is very important to
have all of the wires taut and enuaIjv
spaced from each other. This * to re,
auce the capacity effect between the
wires and give greater efficiency to the
aerial. think that you can do this
very well with No. Is wire. would
not suggest any smaller gauges than
! mat. 8. Providing the tacks do not
snort circuit your wiring | imagine
eiiat you can use this system in con-
strtetlng the aerial, but It IS not very
good one, and would suggest that YOU
get Tour pieces Of insulating material
such as hard rubber, and faster then,
on the ends of the form and then groove
She edges OF these pieces, spacing one
nan inch apart, and wind the wire in
the grooves. 1t will be much neater
looking JOB and give you far greater
eihclency. T. The present number Of
euins On your yario-coupler primary
WIZ pe quite sufficient. You do not
nave 70 interfere with it in any wav.
Q. pe1ofe rewlnding the rotor coil i
~outa nrst Try out the circuit. The
possibility is that you will get results
anyway. provided that the condenser
across the loop aerial has SUFFICIENT 70 :
pacity Ii you do not get good results
you can do the rewiring later on q +
40 not think that you can get the Ar
iihgton TIME signals direct on this sys-
TEN, as doubt vesy much whether it's
teIranc ampllfying powers are avail
aDie at wave lengths in excess of .f)0o
meters. g. The answer above applies to
TINS. D. No variometer was used in II, .
circuit by, Major Armstrong and ~
personally does not recommend tbe use
OF one. However, shall be in q hetfa,.
position to give you advice on this suh.
Ject WITHIN q short time from now. as !
am doing some experimental work, til
EVafiometers in the system. 1t seems n
ihe that II variometer is placed in
Seties Wsln the regeneration coil
one sWoaid also have to be placed in
ssfies Win The grid of the first tube. in
liace oI tiie variable condenser now put
any deflnlte. inform alton on thai no;nt
az this time. | do know, However fbat
tne system as described Ia this nana,
works successfully and we'll. o. Tho
primary OF the vario-coupler can ha
paced IN series with the loon aerial
nut Y functions better IN parallei
" nen M Joined in parallel it also acts IN
q s inter- circuit in connection with the
Sc,voo-cycie = !, ~ current produced BY the
osclliator tube. 10. The mcthod of +,,,,
ing Hne super-regeneratiy, set 4 -
follows: First of all, the condition - -
,he oseliiator circuit can BE determines i
2 py saa very peculiar and characteristie
high pitched whistle. which win aa
heard IN the ieleph ones. Unless tbis
whistle Is heard you will know that tha
osciiiator circuit is not functionine
paoperlv, an ana unless this circuit IS
operating q the whole system IS useless
= you DO not get this whistle vary lI.,. the
condenser sn that is in series between n ,a !
+ aoo %, dgo-laterai coil and the f.5oo duo rs
iatsraa a'l r. coil e you still do not get the
Whlstle Try reversing the coil IS fl,a;r az,
SOCKETS, as It may be that they are a..
posed to each other AS soon 80 s,r ~,
nssr .nis Waistle which. bs the way, Is
received in ordinary radio sets van llgsr IS s
tnen ! tI g.. turn your attentionsto the rsgen- en-.
eratsve anpiificr circuit. I,aava ,sa,,,. s.r..
~ a. x,>os<z