[AMPS] Fwd: [QRO] Fwd: SB-220

[Jon Ogden]

A forward from the QRO reflector.


---------------- Begin Forwarded Message ----------------
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 
> 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!




---
Submissions qro@qth.net


----------------- End Forwarded Message -----------------

-------------------------------------
Jon Ogden
KE9NA

http://www.qsl.net/ke9na


"A life lived in fear is a life half lived."


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