Am Oscillator Pwb - SAC SS-800AVS Manual

2.2.2 AM Oscillator PWB
The Synthesizer PWB output is fed to the AM Oscillator PWB at pin
15 and through Q1 and its associated components is applied to the
carrier input, pin 8, of the RF modulator integrated circuit U2.
After the RF carrier is amplitude modulated in U2, it is filtered
by C18, LI, and C19 and applied through RF Drive control R39 and
Q3 to the Driver PWB. The switched 14 volts for Q3 is furnished
through the Driver PWB from the Auto Shutdown PWB.
The audio input signals to the AM Oscillator PWB are derived from
the AM Recycle PWB and/or from the optional Audio PWB. The audio
signals are combined in amplifier UlA and applied to Modulation
Adjust control R3. The adjusted audio signal is directed through
amplifier UlB to the CRI, CR2 symmetrical clipper circuit. Amplifier
UlC rolls off the high frequency audio components and applies the
signal to the modulator integrated circuit. Test point TPI allows
the audio input to the modulator to be examined.
SS-800AVS Southern Avionics
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