On Jul 21, 2006, at 7:39 AM, Joe Subich, W4TV wrote:
>
> Rich writes:
> ...
> Not likely ... Alpha did not use grid trips in any of the '76 or '78
> series amplifiers.
K-202 looks like it's a grid shutoff.
> I believe they converted to the 3CX800 in the 86
> and 89 amplifiers. I know that all of the 8874 amplifiers tied the
> tube grids directly to ground and did not include any grid current
> trip ... even the 86 with electronic bias switching. The only active
> components were electronic bias switching and QSK boards - none of
> which "opened the grids."
>
> However, since W0UN, AAA0RS and W0ID no longer contribute regularly
> to this forum - schematics for the 76 and 86 amplifiers are on BAMA
> if you care to check the facts before you make wild (wrong)
> statements.
I was looking at Alpha's diagram.
>
>> ...
>> What is the URL of your schematic, Ian?
>
> Ian just gave you the URL of the schematic - it's on pages 30 and
> 31 of the manual.
Found it. thanks, Joe.
> The manual includes an extensive, well written
> discussion of tube protection, how it works and how to configure
> it. However, since it does not agree with your pseudo science you
> don't acknowledge it - as usual.
The Q1 is a TIP-147 and is rated at 5A. Q1 appears to carry grid
current. Is this true?
>
> 73,
>
> ... Joe, W4TV
>
>
>
R L MEASURES, AG6K. 805-386-3734
r@somis.org
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