THE RECEIVER MIXES THE INCOMING SIGNAL AT THE ANTENNA JACK WITH THE SIXTH 
HARMONIC OF THE VCO SIGNAL. THE RESULT IS A 10.7 MHZ IF SIGNAL, WHICH IS 
FILTERED BY AN 8 POLE CRYSTAL FILTER. THIS FILTERED 10.7 MHZ SIGNAL IS 
AMPLIFIED, THEN CONVERTED TO THE 455 KHZ FINAL I/F BY THE SECOND MIXER STAGE.  
A QUADRATURE DETECTOR DEMODULATES THE TRANSMITTED AUDIO FROM THE 455 KHZ I/F 
SIGNAL. WHEN THE SQUELCH ENABLES THE AUDIO AMPLIFIER, THIS AUDIO SIGNAL IS 
THEN AMPLIFIED SUFFICIENTLY TO DRIVE THE SPEAKER.