San Antonio light. [volume] (San Antonio, Tex.) 1911-1993, 1925-10-11
TX Radio Set Can Be Built Easily Amateur Small Cost

first. tuning coil. Run a wire from the
ground binding post to one of the
screws on the rotor portion of the con.
denser. There are four of these. and
two already have been used in wiring
the filament. To the ground wire at
tach the other lead from the tuning
coil.
From. the plate Of the first tube,
run a wire TO the primary binding
post of the three circuit tuner. This
post is on the inside edge of the three
circuit tuner and is the nearest ter
minal to the plate. The other end
of the primary, which can be identi-
fled easily, goes to the Il plus ter
minal on the rear Of the set.
CONNECTING TUNER.
OF the secondary leads of the three
circuit tuner one goes TO the near
est point of the positive a lead auu
also TO one of the rotor binding
screws Of the second condenser. The
other secondary lead goes to the large
screw of the stationary plates which is
nearest to it. From the same screw,
drop a wire directly TO the free END
Of the grid leak condenser, which Is
already mounted on the detector tube.
You will observe that the ticker, or
small movable coil inside the tuner
has two leads, which end in soldering
Tugs.
To one ticker connection run
wire from the plate terminal of the
detector tube. Connect the other to
the post marked "P' Of the first
audio transformer. Which one CT
these ticker connections goes to the
plate and which to the transformer is
extremely important, but is difficult TO
determine without experiment. should
the set fail to work after completion
the connections can be reversed easily.
THE AMPLIFIERS.
Take the .OO2 fixed condenser, and
connect it across the first transformer.
from post "P' to post "B." 1t Will
just fit under the binding post screws
in most instances. From "B" run o
wire to the binding post in the rear OF
the set marked "B" plus detector. v
From &c" run wire to the grid ter
minal of the first simplifying tube,
making the wire as short and direct
ps possible.
= AZ terminal already is connected
to "A" on the second transformer.
From the Plate terminal of the first
simplifying tube, run wire to the top
leaf of the double circuit jack. by
the top leaf is meant the one which
connects with the shorter Of the two
strips which make contact with the
telephone plug.
The second leaf Of the jack. which
makes contact with the first when the
plug is out goes to "P" on the see.
ond transformer, the third leaf to "B"
on transformer, and the fourth leaf is
connected to the "Plus b amplifier'
post on the rear of the set.
&C" on the second transformer goes
to grid of the last tube. "B" is con
nected to b of the first transformer.
"A" already is taken care Of.
The schematic diagram shows a fill
ament control jack in the last stage,
but this is really unnecessary, and
complexities wiring, so The Light used
an ordinary single circuit jack in its
place. Connect the longer leaf to the
"B plus" leaf of the first jack. Con-
meet the other to the plate of the last
tube.
NEUTRALIZING SET.
The set now is complete except for
the neutralizing condenser.
You will note, protruding from the
main coil of the three-circuit tuner, u
twisted loop of wire. Scrape the in
sulation from this and solder on a