On Mar 9, 6:50*pm, "Clams Canino" wrote:
Fact is that anyone can make a stupid mistake, or in the case of the OP a
very legitimate error. In my 30 year involvement with Ham Radio I know
personally of a few guys that became instantly deceased by coming across the
B+ supply of a final amplifier circuit that they designed, built, and used
for years and years before they screwed up. Many of the tube type amps run
4-8kv at 1-2 amps DC. Even forgetting to discharge the filter caps can kill
you deader than dead. *

That ain't no ****.....serious current at that voltage. Actually I'd
think it to be a little more current for large x-mitter tubes. I pay
the bills working on music equipment and a lot of that is tube guitar
amps. A 500v electrolytic installed reverse polarity makes a serious
racket and a huge mess (along with a rank stench) when they vent. My
general rule is check polarity after replacement, then again before
power up. I've never put one in backwards, but I've had 'em go postal
on the bench due to excessive leakage current.....should've been
monitoring the temp since they were 20+ yr old caps. I did have an amp
come in once with someone else's cap job already done and a bias
filter cap in backwards. How that didn't go ka-blooey I'll never know.


IMHO anyone working on this stuff needs to remain
paranoid of safety errors. *In the case of the OP, a good schematic would
have shown the 250v cap and avoided the error.

Actually he should have pulled off the glue-gunk to verify what came
out. Going by a list and checking them off as they were replaced
should've raised a red flag.