TB 9-6625-2043-24
15. Chopper Frequency
a. Performance Check
NOTE
Do not perform chopper frequency checks if all other
parameters are within tolerance.
(1) Connect negative edge of frequency counter to RECORDER connector on rear
(2) Connect TI power detector to function/arbitrary generator Output.
(3) Zero TI meter as described in paragraph 7 h above.
(4) Set FULL SCALE switch to -30 dBm.
(5) Adjust function/arbitrary generator output for a 30 dBm indication on TI meter.
(6) Set frequency counter to measure period. If frequency counter does not indicate
between 10.50 and 10.80 ms, perform b below.
b. Adjustments. Adjust R244 (fig. 1 or 2) for a 10.65 ms indication on frequency
counter (R).
16. Low Voltage Power Supply
NOTE
Do not perform power supply check if all other parameters are
within tolerance.
a. Performance Check
(1) Connect negative side of multimeter to - (negative) RECORDER connector on
rear panel, and positive side of multimeter to -15 V TP (fig. 1 or 2). If multimeter does not
indicate between -14.9 and - 15.1 V dc, perform b (1) below.
(2) Connect positive test lead to +15 V TP (fig. 1 or 2). If multimeter does not
indicate between +14.9 and +15.1 V dc, perform b (2) below.
b. Adjustments
(1) Adjust R143 (fig. 1 or 2) for a -15.0 V dc indication on multimeter (R).
(2) Adjust R140 (fig. 1 or 2) for a +15.0 V dc indication on multimeter (R).
Final Procedure
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.
