The Monmouth inquirer. [volume] (Freehold, N.J.) 1865-1933, 1926-01-28
BY EDGAR Il. FELIX
In PHILADELPHIA Record.


The superior quality Of reception
obtainable with loud volume by the
substitution Of Tx 112 and Tx 120
tubes for wv 201-A and Nv 100 tubes,
respectively, in the last stage of
audio-frequency application, makes
their installation of interest to every
owner of a receiver having two or
more stages of audio-frequency ampi-
f1cation. Several important changes
must be made in the wiring of the
receiving set to adapt the circuits
and power supply to the needs of the
new tubes.
The Tx 112 is the big brother of
the wv 201-A tube. The filament cur
rent consumption of the new tubes is
half an ampere, only double that of
the economical wv 201-A. To secure
satisfactory results with the UX 112
tube, 1876 volts of plate potential are
required, as compared with 80 volts
usually used with the Nv 201-A. Fur
thermore, unless the 8 volt "C'' bat
terry is used in connection with it,
the Tx 112 is a heavy user of 'B"
battery current and distorts consider
ably. BY the addition of the "C'
battery, however, large size ''B"
battery can power this tube for a
year or more 1t is not necessary to
use an extra large or heavy duty size
'B' battery for furnishing the extra
45 volts required by this tube.
NNK.. \
45 volt "B" battery is as follows: "a
Examine the socket which holds the
tube used in the final stage of ampli-
fication and identify the plate termi-
nal, usually marked "P." (2) Discon-
meet the wire attached to this termi-
nal. (3) Connect the positive termi-
nal of the new extra As volt ''B'' bat
terry to the plate socket terminal. "a
Connect the negative terminal of the
new "B" battery with the wire which
you have just disconnected from the
plate socket terminal. This gives
total voltage of 1876 volts on the Tx
112 tube, but 1t does not increase the
plate voltage Of the Nv 201-A tube
in the first stage of audio-freQuency
application.
Adding the Extra &C" Battery.
A somewhat similar method is pur-
sued In adding the extra Az volt &c"
battery. The new "Cv battery is con-
nected in series with the one already
Installed; the existing connections of
the latter with the first stage of ampli-
fication are not disturbed. The sec
ondary of the second dio-frequency
transformer. however, Is disconnected
from the 411a volt terminal of the
original &c" battery, a new lead be-
ing run from that secondary terminal
to % volt terminal of the new &c"
battery.
For dry cell tube sets using Nv 100
tubes, the new UX 100 is used in the
last stage This also requires 1876
volts plate potential obtainable from
large size "B" battery The same
instructions for connecting the extra
As volt ''B" battery for the Tx 112
apply to the Tx 100.
The Tx 100 requires 221z volt
&C" battery. Substitute for your pres
ent 20" battery 221s volt tapped
"B' battery made up Of large size
cells. This assures you Of long shelf
life. There is practically no current
withdrawn from the &c" battery and
consequently. It's usefulness is deter
mined by its shelf life.
A &c" battery is connected in the
reverse direction as compared with a
sBs battery. The "B'' battery is
connected with the plus to the plate
and the minus toward the filament.
The &C. battery, on the other hand.
| Is connected with the negative termi-
nal toward he grid and the +221z
volts to the filament The full voltage
of the battery Is impressed upon the
grid If the grid return is made to
the minus connection of the battery,
since It's plus lead Is connected with