GENERAL RADIO COMPANY 1263-8 Operating Instructions Manual page 14

TYPE 1263-B AMPLITUDE-REGULATING POWER SUPPLY
3.1.2 OUTPUT-RECTIFIER CONNECTION. With a Type874-R22 Patch
Cord, connect the OUTPUT RECTIFIER connector of the Type 1263-B
to the de output (side connector) of the Type 874-VR Voltmeter Rectifier.
The Type 874-VR should be connected as close as possible to the
output connector of the oscillator, either by direct plug-in or with an
output filter interposed (refer to Section 5). The resistor end marked R
should face the load to provide a matched source for a 50-ohm coaxial
line. A Type 874-EL 90
°
Ell and Type 874-Z Stand are useful acces-
sories for connecting and supporting the output filter and Type 874-VR.
Adaptors are available for connectors other than Type 874. Refer to the
table of Type 874 Accessories at the rear of this manual.
3.2 HEATER-SUPPLY VOLTAGE ADJUSTMENT.
There is a considerable variation in the heater-current require-
ments of the various Unit Oscillators. A compromise in voltage supplied
permits satisfactory operation without adjustment. Output is 6 volts at
0.5 ampere with the nominal line-supply voltage. Heater-current require-
ments for oscillators are met as follows:
a. Types 1209-BL, 1209-B, and 1215-B: 6.3 volts at 0.3 to 0.4 am-
pere.
b. Type 1211-B: 5.4 volts at 0. 7 ampere satisfactory (nominal re-
quirement is 6 volts at 0. 75 ampere).
c. Type 1218-A: has internal heater rectifier. Polarity of de sup-
plied by Type 1263-B Power Supply is chosen so that this rectifier con-
ducts. Oscillator current requirement is less than 0.2 ampere. The drop
in the rectifier and associated filter
is
such that proper voltage is sup-
plied to the tube.
d. Type 1361-A: 7 volts at 135 rna. Voltage drop within the oscil-
lator reduces the voltage at the tube to 6. 7 volts, which is satisfactory
for normal use.
If
the Type 1263-B Power Supply is to be used only with
the Type 1361-A Oscillator, remove the jumper as described below.
e. Oscillators requiring less than 0.2 ampere at 6.3 volts: Remove
the jumper that connects the terminals of the electrolytic capacitor at
the top center of the Type 1263-B. This jumper is accessible from the
rear after the dust cover and V2 are removed.
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