TB 9-6625-1999-35
8. Audio Oscillator
a. Performance Check
(1) Position controls as listed in (a) through (c) below:
(a) RANGE switch to 530 - 1800 KC.
(b) MODULATION AMPLITUDE control fully ccw.
(c) MODULATION SELECTOR switch to INT 400 ∼.
(2) Connect frequency counter to MODULATION INPUT-OUTPUT. If frequency
counter does not indicate between 380 and 420 Hz, perform b below.
(3) Set MODULATION SELECTOR switch to 1000 ∼. If frequency counter does
not indicate between 950 and 1050 Hz, perform b below.
(4) Vary autotransformer output between 105 and 125 V ac and back to 115 V ac.
Frequency counter will indicate between 950 and 1050 Hz.
b. Adjustments
(1) Connect multimeter between A1T1 AUDIO TRANSFORMER (yellow lead on
tie point) (fig. 1) and chassis ground.
(3) Repeat a above.