20 Sep
2010
20 Sep
'10
1:27 p.m.
<comes out from bushes> ah, that was me.
Was a great time and really a blast to dig into the Alto. We definitely
improvised, not having a stock of uA709 opamp on hand... we just bypassed
that regulator circuit and stuck a 7805 there instead, which was pilfered
from Vince Briel's spare parts stock for his Altair8800micro kits.
Too much fun.
I think if i has a machine as rare as an Alto, I would try to keep the
circuitry as original as posisble. In other words, I'd not bung in a 3
terminal regulator hore.
The 709, IIRC, uses external compensation, while most more modern op-amps
don't. But that shou;ldn't be much of a problem for a PSU regulator
circuit. I would try to fidnm an op-amp that owuld work here (even you
can't stil lget a 709 anywhere...)
-tony