A forward from the QRO reflector.
---------------- Begin Forwarded Message ----------------
To: <amps@contesting.com>
Date: 07/13 15:09
Received: 07/13 17:58
From: Brian Short, k7on@qsl.net
To: qro@qth.net
>
> From: "Greg Weremey"
> To:
> Subject: SB-220
To: <amps@contesting.com>
> Date: Mon, 13 Jul 1998 12:57:11 -0400
> X-Mailer: Microsoft Outlook Express 4.72.3110.5
>
> Hi Brian,
> ?
> I have an SB-220 amplifier that has low output.?? I see from your page on
> amplifiers, that the SB-220 should produce 600w (in CW mode) and 1200w (in
> SSB mode).? My amplifier produces only 450w in CW mode and about 525w in SSB
> mode with 100w drive from my Kenwood TS-830S.? My plate voltage is 3Kv in
> SSB, and the plate amps are 400ma (voice SSB) and 900ma CW.
> It appears that the 3-500Z's are drawing and are in good shape.? I can excite
> the amplifier with 5w and get 100w output.
> It almost looks like the output hits a "brick wall".? I don't see that this
> is due to voltage starvation.? Could it be caused by RF output going to
> ground or somewhere other than the output SO-239?? Tuneup is normal and the
> tuning cap has a good sharp null.
> ?
> The amplifier was purchased at a HAM flea at M.I.T. and appears to be in good
> condition.
> If you have any thoughts, please point me in the correct direction.
> ?
> Thank you in advance.
> Sincerely,
> Greg Weremey - N1JFE
> ?
> 73!
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Submissions qro@qth.net
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-------------------------------------
Jon Ogden
KE9NA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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