San Antonio light. [volume] (San Antonio, Tex.) 1911-1993, 1925-10-18
HERE ARE HINTS
To MPROvE
OPERATION
Small Adjustments Often
Spell Vast Difference
in Reception.

The Sunday Light last week pub.
lished directions for the construction
of simple four-tube regcnerativc
receiver of great efficiency and Sc.
lectivity. which is non.radiating ana
which, operating on n short antcnna
gives results equalling, if not exceed.
ing, those obtained from receivers
using one or more additional tubs.
Many Light readers have inquired
where parts for this set may be OBJ
tanned. The Light GDes not recon-
mend any particular dealer above an
other, and all that can be said is that
any standard radio part of the size
and capacity indicated in the dia-
gram accompanying the article will
do. So shop around and see What
you can pick up.
COMMISSIONING.
Notwithstanding in the Browning
Drake receiver is a simple matter. us
there is little that can go wrong.
Perhaps the commonest complaint Of
those who have constructed the set is
that il cannot be made to oscilla;c.
This trouble almost invariably will
be found to result from an improper.
ly connected ticker.
When the leads to the ticker coil
are reversed, its effect on the circuit
is to dampen oscillation instead of
aiding it. Try reversing the wires
leading TO the ticker. Nine times QUIZ
of ten it will be found that the set
now will oscillate properly.
II this procedure fails to bring re-
suits, 20 over the battery connec-
tions carefully and make sure that the
a battery wires are connected IL
their proper posts. If these leads are
reversed the tubes. while lighting as
well as ever, will not work, since a
positive bias has been put on the grid,
aud the flow of clcctrons practically
halted. i battery leads must also be on
their proper binding posts. for similar
reasons.
SOOTHING THE SET.
To run down and eliminate noise in
the set, other than static, the antenna
should first be disconnected. II the
noise ceases, it is proof that the dis
turbance originated somewhere outside
the set, and cannot be remedicd by
any change in the receiver.
IL the noise persists, remove the
first tube, and listen again: IT it has
stopped, either the tube is faulty and
should be replaced, or some detail Of
the wiring Of the first tube is in
correct or poorly done.
II the noise is still there remove the
second tube as well. and then the third.
tinue, they are probably due TO some
wiring fault common to all tubes, such
ss one OF the battery leads, a poor
rheostnt or filament switch, a poorly
soldered joint, outwardly sound, may
be introducing resistance into some
part of tho circuit which will make the
receiver howl to high heaven. Test
all your connections. and If there is
the slightest give" to a joint, solder
it over again.
CAUSE OF SQUEALING.
Unwonted squealing in the set will
be found due to: Turning the ticker
up too far; failure to neutralize the
first tube properly: an improperly ar.
ranged audio amplifier. A steady howl
which cannot be changed greatly by
bly, means that the primary Of the
first audio transformer is improperly
connected. Try reversing the leads to
this transformcr-that is, swapping the
wires which connect to the binding
posts marked primary"
The Light last week described one
method OF neutralizing the first tube
of the set by tuning in a station, in
sulating a filamcnt prong OF. the tube
and then adjusting the ncutralizins
condenser until the station could not
be heard.
NEUTRALIZING.
A somewhat simpler way is to con
meet ono OF the terminals Of your head
SGT 10 the aerial post and the other
10 the ground post. IL you hear o
whistle when t,Ie tubes are lighted and
the ticker turned. the set is oscillat-
ing improperly and radiating dis
turbipg noise for benefit OF your neigh
bors who are listening.
Slide the sleeve of the little con.
denser back and forth until you find
n place where this squeal disappears.
At that point the tube is neutralized
and you arc no longer a public nui-
sance.
The set, made properly, is extreme
" selcctive, cutting out Station
VICAR with a slight movement Of the
second dial, and tuning out the other
radio station Of the city by turning
she dial five to 10 degrees-somcthing
which few other sets can accomplish.
WHAT DOES 1T.
Should this TIMING control he broad,
however. It indica,Ss that not enough
ticker is being used. BY bringing the
ticker up TO point just below oscil-
lation, it should be possible to make
this control exceedingly sharp. II
your antcnna is very long it may make
the first condenser tune broadly. The
Insertion Of the .0001 fixed condenser
in the antenna lead is supposed to
counternct this. Try substituting q
.O0025 or .0005 condenser in place OF
the .0001.
If the detector oscillates and the set
tunes sharply, yet volume is not all
that could be desired, the trouble lies
in the audio amplifier or in the ampli-
fying tubes. Sometimes merely chang
ing the order of the tubes in their
.octets will do wonders for the volume