Am Oscillator Pwb; Preliminary; Frequency And Modulation Adjustment - SAC SS-800AVS Manual

6.2 System Alignment and Calibration
SS-Series radiobeacons d__o not normally need anx adjustment in the
w_~yof alignment or calibration. However, if such procedures become
necessary, ~he followinq aliqnment procedures must be observed:
6.2.1 AM Oscillator PWB
6.2.1.1 Preliminary
Before making any adjustment to the AM Oscillator, the following
preliminary setup should be performed:
With AC power removed, disconnect the antenna system and connect
the dummy load by transferring the jumper on TB4 from the BNC
terminal to the dummy load terminal (see drawing for "Trans-
mitter Diagram").
2. Turn the RF DRIVE control on the AM Oscillator PWB to its full
low level (CCW) position.
3.
Put Switch Sl on the Recycle PWB in the continuous carrier
positionn (CARR).
4. Set the Auto Shutdown PWB switch to OFF.
6.2.1.2 Frequency and Modulation Adjustment
i. Connect an oscilloscope to the dummy load.
2. Remove the RF shield from the transmitter chassis to allow
access to the AM and voice modulation circuit PWB's.
3. Adjust the following controls on the AM Oscillator PWB fully
CCW.
a. Modulation Adjust (R3).
b. Modulation Limit (RI2).
c. RF Drive (R39).
NOTE: These controls are 15 turn pots and possess a slight
detent action at the limits of rotation.
Adjust the following controls on the Audio PWB (optional) fully
CW.
a. Audio Input Level.
b. Modulation Adjust.
SS-800AVS Southern Avionics
Company
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