Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1922-05-01

-" AouiV AuuS tuIh HOUuC FrekeHerQs
tive circuits" In every radio maga-
zine you vii see it stated over and
over again that the resenerative circuit
Is the, best circuit for the reception of
signals sent out on such short wave
lengths as arc used by the broadcasting
stations. ya 70.
I've promised not to be too technical
in these articles, so We won't 70 into
the details. Of regeneration too deeply.
Whenever you see diagram Of hook.
up stating It is employing this prin.
ciple. you can get ahead safely and
use It whether you understand why It
ts good or NOT: And any diagram which
shows q coil marked "tickler" is a re.
senerative circuit. -.
Briefly, the ticker is coil Of any
kind used to take. the current from the
dry cell, or ''B'' battery, and "feed It
back"sto the original, or primary. coil
that the aerial hooks toA-the feed
back being done. in such way that
the battery current, BY it's own
strength, gives adds;: strength to the
weak currents coming in. through the
aerial. The result is h signal built up
considerably beyond the strength It
would have had II 1t hadn't been tickled.
The tickling seems to make it laugh
louder in joy, -
You needn't be worried il you cannot
quite see how this is done. You can
operate set successfully without a
clear idea of IL. -
Any kind of coupling coil. If hooked
up properly, can be used in the form
Of a regenerative circuit by the diagram
shown here. All coupling coils have
two binding posts marked "aeriar' and
ground" (Which are simply the two
ends of one. coil known as the ''pri-
marry and another pair of binding
posts for the coil known as the ''sec-
: II you are using loose coupler or
hOneycOmb coils or homemade spider
web coils. simply substitute them for
the "variocoupler' shown in the dia.
gram. -. -. - F..s
The secondary coil then ceases to be
a secondary, and becomes a ticker, and
the circuit becomes a rcgenerative cir.
cult. ~.
There is one interesting point about
this, though. II two fellows are using
the same aerial. the fellow in one
house using rone wire and the fellow in
the other house using the other, neither
one must use this circuit. Any circuit
which eliminates the secondary coil be-
comes what Is known as single cir
cult hook-up, and the odd part Of Q
single circuit hook up is that. all the
time you are using it to receive on,
you are. unknown to yourself. sending
xl,, - la ASA~ ,snH
will cause a loud hum in any nearby
aerial and interfere with your neigh.
boris reception of the broadcasts.
II you and your neighbor are using
the different wires of the same aerial or
IL your neighbor's aerial Is very near
to your own, you had better sign a
truce, both agreeing to use one of the
regenerative hook ups which provide for
secondary coil. Then you won't in
terfere with each other.
This circuit is not the standard re-
generative hOok.up which is usually
meant by that term. That hook. up re.
quires two "variometers" in addition
to the coupler. and in that case the
extra coil Of the coupler is used as a
secondary.
The hook up given here Is more COM
plicated than the usual one, but is much
simpler in operation. The standard one
is simpler in. wiring, but much more
difficult to operate successfully. be-
cause it has more adjustments. This
one is easier to find signals with, but
is not so ''selective'--that is, II there
are other stations sending on the same
wave lengths, 1t may be impossible to
'''tune them OUT with this hook up,
whereas, if you know how to use the
standard regenerative circuit, you can
tune out almost anything you don't want
to hear.
But this circuit issby all odds the
best for the beginner, and its great ad-
vantage Is that it ia cheaper than the
other, and that all the instruments used
here will also be used in the standard
hook up when you buy your two vario.
meters and try it.