BCC39 ATUs are showing up as surplus on that "e" place. Someone in the UK has figured out the following so far. Just an fyi.
I have unravelled the program and understand most of what it does at a software/hardware level,
and I am planning a simple "tune initiate" circuit to add on to the
unit and supply it with power and auto-tune commands. It needs 5volts
on the coax to the BNC connector, but this is supplied from the BCC39
24volt supply rail by a dropper resistor and RF blocking RFC etc. The
command bits are inserted by brief interruptions to the supply, using a
FET in the TCVR to pulse width modulate a signal which is picked up
by the interrupt lines on the MPU in the tuner. It tunes in about
300 mSec, and I have had very good reports using quite short wires
from the BCC39 I was lent.
