Transmitter System - Alinco DJ - C7 T Service Manual

2) Transmitter
1. Microphone Amplifier
2. Power Amplifier
6
The microphone amplifier IC301 has 2 operational amplifiers. The voice is
converted into the electric signal through the microphone, and then supplied
to IC301. The input signal is amplified and pre-emphasized to be output.
[VHF]
The signal output from microphone amplifier is adjusted the maximum
frequency deviation at VR2. The adjusted signal is added to the cathode of
VCO variable-capacitor D4 for deviation to change the capacity of the
oscillation circuit resulting the FM deviation.
[UHF]
The signal output from microphone amplifier is adjusted the maximum
frequency deviation at VR1. The adjusted signal is added to the cathode of
VCO variable-capacitor D10 for deviation to change the capacity of the
oscillation circuit resulting the FM deviation.
The oscillated signal at VCO is supplied to the power amplifier Q3, passing
through buffer amplifier Q5, driver amplifier IC1. The power-amplified signal
is supplied to the antenna through the duplexer after the harmonics are
attenuated enough.