TM 11-6625-3053-14
ITEM
MALFUNCTION
CHECKS/CORRECTIVE ACTION
5. Check Q1 and Q2 regulators.
a) Using the multimeter, set to 1000 VDC range and measure
voltage between test pin 12 and the collector of Q2 on the A2A1
card.
Voltage should be approx -238 VDC.
If voltage is not obtained, replace Q1 and Q2 as needed.
If voltage is obtained, go to check 6 below.
6. Check AR1 input.
NOTE
Modulation is still in CW.
a) Using multimeter as set, measure voltage on pin 3 of AR1.
Voltage should be approx -6.0 VDC.
If voltage obtained, go to step 7.
If voltage not obtained, check CR8, CR9, and CR10, capacitor
network C2, C3, and C4, and resistance network R6 through R10
in that order. Replace faulty components.
7. Check error amplifier AR1 output.
a) Using multimeter, set to 10 VDC range. Measure voltage
between test pin 12 and pin 6 of AR1.
Voltage should be approx -2.5 VDC.
If voltage is not obtained, replace AR1.
7
Cannot aline -325V Beam Supply-Check A2A3 Card Assy.
1. Check -325V output. If already known to be incorrect, go to check 2
below.
a) Remove instrument dust cover if on (para 6-20).
b) Remove high voltage cover if on (para 6-22).
c) Set multimeter to 1000 VDC range.
d) Set sig gen to initial settings of para 2-4.
e) Energize sig gen and multimeter.
f)
Wait 2 mins and set MODULATION Switch to CW.
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