Belt Valley times. [volume] (Armington, Mont.) 1894-1977, 1926-02-04
BY eDoAR \. FELIX
in PhIladelphla Record.

N rntiaoeipnia RECORD.
The superior quality OF reception
obtainable with loud volume by the
substitution Of Tx 10 and Tx 100
tubes for wv 20l-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 audin-frequency ampll-
location 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 Nv 201-A tube. The flament cur
rent consumption of the new tubes is
half an ampere. only double that OF
the economical Nv 201-A. To secure
satisfactory results with the Tx 112
tube. 1876 volts OF plate potential are
required, as compared with 90 volts
usually used with the wv 201-A. Fur
thermore, unless the volt &C" bat
terry Is used In connection with It.
the Tx 10 ls a heavy user OF s.B,,
battery current and dlstorts consider
ably. BY the addition OF the "c''
battery. however. a large size "B"
battery can power this tube for
year or more. 1t Is not necessary to
use an extra large or heavy duty size
''B' battery for furnishing the extra
IS volts required By this tube.
The method Of connecting an extra
As volt "B" battery Is as follows: "a
Examine the socket which holds the
tube used in the final stage OF ampli-
ncatIon and identify the plate terml-
nal. usually marked "P." (2) Discon-
meet the wire attached to this termi-
nal. CD Connect the positive terml-
nal OF the new extra IS volt 'B" bat
terry to the plate socket terminal. "a |
the negative terminal OF the |
new "B'' battery with the wire which
you have just disconnected from the
plate socket terminal. This gives a
total voltage Of 1886 volts on the Tx
I12 tube, bat It does not increase the
plate voltage Of the Nv 201-A tube
IN the first stage OF HudiO-frequency
Adding the extra &C" Battery.
A somewhat similar method Is pnr-
med In adding the extra AZ volt &C"
battery. The new &C. battery Is con-
lected in series with the one already
the existing connections OF
he latter with the first stage Of ampIl
ication are not disturbed. The sec
,ndary Of the second autobiography
however. is disconnected
rom the -41k volt terminal OF the
,riginaI "C' battery. q new lead be-
az run from that secondary terminal
o % volt terminal OF the new &C"
artery.
For dry cell tube sets using UY 100
ubes, the new Tx 100 Is used 10 the
asst stage This also requires f35
otis plate potential obtainable from
large size 'B" battery. The same /,
for connecting the extra
5 volt ''Bv battery for the Tx 112
ppiy to the Tx 100.
The UX 40 requires a 221k volt
c" battery Substitute for your pres
Of ~C~ battery a 2zH volt tapped !,
B. battery made up Of large size !.
Ills. This assures you Of long shelf
fe There is practically no current
ifhdrawn from the -C~ battery. and
,nsequently. its usefulness Is deter
lined by it's shelf life.
1
A or battery h connected IN the =
verse direcflop as compared with a
b. battery Ehe .sBss battery Ia 2 2
with the plus 70 the plate &
I'd the minus toward the dlament. "
he &C battery. on the other hand. Q
connected with the negative termi-
j toward he grid and the t22h
Hts to the fIament. The full voltage
the battery ia impressed upon the n
ID II the grid return is made to e
e minus connection Of the battery, q
ace its plus lead is connected with g