TM 11-6625-2948-14+P
(1) Set the signal generator for CW operation (see para-
normal operating conditions, voltages should be below +40
volts at test points. A failure, however, in the high voltage
box 1A5 could bring this level up to several hundred volts.
(2) Set digital multimeter to the 20 VDC range. Connect
Caution should, therefore, be used when locating the end of
pin 4 of the test connector 1A4TP to V of the multime-
the cable and when making measurements. Viewing from
ter and pin 2 to COMMON.
the top of the connector, the pin numbers will be marked
as follows:
(3) Adjust BEAM CURRENT ADJ control 1A5A2R5
(fig. 4-6 and 4-6.1) for 2.50 V
2l0% on the rnultimeter.
4
1
r
r
(4] Scan through the frequency band and readjust so that
2
5
2.50 V is minimum at any point.
r
r
3
6
(5) Glyptol-lock BEAM CURRENT ADJ potentiometer
r
1A5A2R5.
r
The following voltage Table 4-3 indicates normal opera-
t i o n , when the MODULATION SELECTOR switch is in
on.
the CW position and the voltage is at 115 vat.
e. Filament Voltage Adjustment.
After checking the voltages listed in Table 4-3, monitor the
klystron beam current (pins 4 and 2). With the MODULA-
(1) Connect the digital voltmeter to pin 2 of connector
TION SELECTOR switch in the CW position, the voltage
1A3J3 (fig. 4-9 and 4-9.1) and the COMMON Iead to I
should be between 2.5 and 2.9 volts. Push in RF OFF
Pin 3 of connector 1A3J3.
control and the voltages should drop to 0.4 volts. Push
in IN SQ WAVE control and the voltage should Increase
(2)
Adjust
6.3
Adj
control
1A3R2
for
+
6.3
volts
to 1.4 to 1.6 volts.
Pin 3 controls the delay circuit, which allows the klystron
filament to warm up before the application of the high
voltage. During the first minute, the voltage at the pin will
be approximately 800 millivolts. It will drop to 0 volt
The Test Connector, A713772, supplied as part of the
when the high voltage is activated. This is indicated when
accessory kit, is used to assemble a test cable to aid in
RF signal is generated. The delay circuit may be over-
evaluation of the performance of the signal generator and
ridden if pin 3 is shorted to ground. The RF signal will
implement voltage adjustment. The cable may have a
slowly build up as the filament is heated.
length of up to four feet without affecting performance.
Test
Pin Nos.
Indication
Tol
--
4(+) to 2
10%**
Klystron Beam Current
2.7 vdc
1(+) to 2
Low Voltage DC Power Supply Voltage
31 vdc
10%
10%**
5(+) to 1
LOW Voltage DC Power Supply Current
450 mvdc
6(+) to 2
* * Low Voltage Bias
12 vdc
10%
*The bias voltage must be read during the first minute after turning on the set (klystron filament warmup interval before
the high voltage is applied).
**This is equivalent to 27 ma going through 1A5A1R8.
***This is equivalent to 2.25 amp going through 1A4R1.