20 Sep
2010
20 Sep
'10
3:15 p.m.
On 9/20/10 2:49 PM, Brent Hilpert wrote:
TO-99 709s are difficult to find, but not impossible. For most
applications I believe a 741 can be used as a drop-in replacement for a
709; this being a voltage regulator I'd guess it probably isn't all that
demanding on the 709's particular specifications.
It wouldn't be 100% historically correct, but if you think about it,
that would likely have been a reasonable repair method during this
machine's service lifetime.
I'd say do it.
-Dave
--
Dave McGuire
Port Charlotte, FL
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.
If the 709 was a TO-99 (can) package and you need to replace it, I have
lots of 741's in TO-99.
Just mentioning it in case it is difficult to find a 709 in TO-99. (DIP
should be easy to find something to substitute.)