Mike,This may or may not be what you are looking for.
I posted this some time back.
BC780 INTERNAL SQUELCH ADJUSTMENT
(Note: Doing this will probably void the warrantee. Proceed at your own risk)
RT 3 is the internal adjustment for NFM and RT 7 is for standard FM.
Since there have been a number of complaints about the different threshold
settings, I decided to test the range of these adjustments.
After tweeking and measuring for some time I found the optimum settings.
(No help on the huge hysterisis problem. Sorry) Set two channels up on a
UHF frequency like 446.0000 MHz. One on standard FM, the other on NFM.
Carefully adjust the minimum squelch threshold on the standard FM channel.
Switch to the NFM channel and try to do the same. Note the position where
they closed. If they were the same DO NOT DO ANY ADJUSTMENTS.
If they were different, go back to the standard FM channel and carefully set
the minimum threshold again. (be as close to the edge as possible)
Set the scanner to the NFM channel and very carefully adjust RT 3 to where
the noise stops. That should make both of the even. Test the two modes back
and forth to verify they set the same. YOUR DONE.
I tested this across all frequencies and found it worked well if you did this
on a UHF frequency. All other bands behave well. UHF is very sensitive on
this radio. Squelch breaking on different bands is a little different but close.
It was a good idea that Uniden made a separate circuit to do the upcoming
NFM channel spacing. The federal government has been using NFM for a
while. Uniden did it right. Volume is boosted on NFM to compensate for the
lower deviation FM. Selectivity is tightened to reject better. Good job Uniden!
Too bad they did not set the squelch better in the factory.
Phil (N2HUC)
