Answer to John Miles,
He wrote:
1) NEVER remove or disable a crowbar circuit. It was triggering for a
reason! You're very lucky not to have done serious damage to your
analyzer
and plugins by removing CR10. This is no different from shorting a
fuse to
find out why it blew.
Reply: I had to, because I did not have a memory scope and the full
set of test cables. This was temporary.
He wrote:
2) Germanium pass transistors become leaky with age. These need to be
replaced as a matter of course in any equipment older than the mid-70s.
Daniel's 8552B dates from 1975, or at least its revision level does. They
can almost always be replaced with modern silicon power transistors
with no
ill effects.
Reply: The pass transistor is silicon, Si, not germanium, the manual
says Si and that was confirmed by test on a curve tracer. Leakage
would cause the problem to be worse at light load. I had a problem at
full load, but all was OK with a light load.
Regards
Daniel from Ville Saint-Laurent, QC, Canada.
