> From: "NOLL AMIDZICH" <NOLLAMIDZICH@classic.msn.com>
> I am an owner of an ALPHA 77DX AND a 87A. The 77dx I've had since 1983. It's
> a
> great amp especially for one who wants to contest 48 hours and not worry
> about
> "blowing things up".
> However, having said that, since 1983 I've had to replace 1 vacuum relay and
> 3
> ( 2 of which were put into service as new) 8877 tubes. It's still a great amp
> and I believe a lot of 8877s "went west" for various and sundry reasons. I've
> always tried to keep the grid current as low as possible but things do
> happen.
That's right. All the stuff about parasite and so on is just technical
nonsense designed to sell suppressor kits.
8877's have had a history of service problems over the years. They
were dandy tubes when made in San Carlos, they were not so good when
made in Salt Lake City, and now that they are back in San Carlos they
seem to be just fine again.
For a period of time in the late 80's, over 90% of brand new tubes
failed in filament cycling tests by developing grid / cathode shorts.
The new 8877's seem to be just fine, so I'd not worry much. But I'd
sure avoid pull-outs or old code date tubes, unless they are real
old (pre- or post- Salt Lake vintage).
73, Tom W8JI
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