Service Manual Part 1
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8- 111114"113)6
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8-8 111114"11#
The incoming signal from the antenna via the PIN switch passes through a high pass fil-
ter to the RF amplifier, Q101. The 50Ω output from the amplifier is coupled to a varicap
tuned triplet which provides the spurious response rejection necessary for the first
mixer. An attenuator is provided at the output to allow for fine adjustment of the front
end gain.
The VCO output is fed to the first double balanced mixer via a low pass filter to reduce
harmonic content. The VCO signal is 27.7MHz below the RF signal and the first mixer
output (at 27.7MHz) feeds the first post-mixer buffer, Q103. The output of Q103 feeds
both a delay line and the noise blanker circuit.