User's Manual Part 5
123) -
8&!!
Optional circuitry is provided by IC7 to inhibit the VOX signal from the received audio,
instead of BUSY. LINK4 is removed to disable the BUSY inhibit and the RX-AUDIO
inhibit is enabled by changing LINK5A to LINK5B.
Receiver gated audio is buffered by IC7 pins 12, 13 & 14 and split off to feed into the
VOX noise path (IC3 pins 5, 6 & 7) and also to a precision rectifier formed around IC7,
pins 1, 2 & 3. The rectified audio signal is compared by IC7 pins 5, 6 & 7, and operates
the inhibit circuit, Q14.