TM 11-6625-1633-45
Figure 3-10. Terminal Board TB3-A2, parts location diagram.
(6) Replace the tubes, indicator lamps, and the
NOTE
Do not remove the klystron.
klystron socket when the short-circuit tests have been
completed.
(3) Remove the POWER indicator lamp as out-
lined in TM 11-6625-1633-12.
c. Make the measurements indicated in the chart be-
(4) Remove klystron socket A4J4.
low. When a faulty part is found, repair the trouble be-
(5) Set MODULATION selector switch S2 to OFF.
fore applying power to the unit.
Short-Circuit Test Chart
Point of measurement
Normal indication (ohms)
Isolating procedure
If resistance is zero, check for shorted
Between tests points A4TP1 and A4TP3
About 4.7K with negative probe on test
diodes CR20 through CR23 (fig. 3-12)
point A4TP1. About 5K with negative
or shorted transformer T3 (fig. 3-2).
probe on test point A4TP3.
Replace detective component.
Between pins 2 and 4 of klystron A4V1
About 900 ohms
If resistance is zero, check for shorted
KLY FIL potentiometer R70 (fig. 3-4);
if resistance is low, check for shorted
capacitor C40 or C41 or diodes CR10
through CR13. Replace defective
component.
If resistance is zero, check for shorted
Between test point 4ATP1 and pin 3 of
About 120K
filter capacitor C33 or C34 (fig. 3-2).
klystron A4V1 (fig. 5-8).
Replace defective component.
3-10
