charging problem, replacement radio?

[jos1 at cornell.edu]

I have a peculiar charging problem on my '89 100Q: neither digital nor
analog gauge show any charge from cold start before approx 3500rpm --
after hitting this rpm range it charges fine at any rpm.  Changed out
the (damn expensive!) voltage regulator, with no change in symptoms.
Anyone have a clue? (FWIW, the console battery/charge light no longer
functions either).

On a seperate note, does anyone have a stock Delta radio they wish to
part with?  The on/off/volume switch on mine got flaky, turning off
spontaneously, and now won't even turn the radio on.  No shop wants to
repair it ("Sorry sir, we can't assume the liability") and the local
bone yards are shy of Audis.

TIA

jos