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RE: [Amps] SB-200 80 Meter dilemma

To: "Bridges Donald T Capt 92 ARW/HC" <donald.bridges@fairchild.af.mil>,<Ka7lpo@aol.com>, "AMPS" <amps@contesting.com>
Subject: RE: [Amps] SB-200 80 Meter dilemma
From: R.Measures <r@somis.org>
Date: Fri, 27 Feb 2004 22:15:37 -0800
List-post: <mailto:amps@contesting.com>
The bandswitch contacts may have been toasted.  The  fixes are:   replace 
the burned contacts, or replace the switch wafer.

>Sir,
>Thank you for your advise. I will try your suggestion. For
>clarification, are you suggesting that the switch contacts need repaired
>and/or the DC-blocker cap may need replacing?
>Don
>
>-----Original Message-----
>From: R. Measures [mailto:r@somis.org] 
>Sent: Friday, February 27, 2004 3:40 AM
>To: Ka7lpo@aol.com; AMPS
>Subject: Re: [Amps] SB-200 80 Meter dilemma
>
>**  Sounds like the 80m Tune-C padder cap switch contacts have been 
>evaporated by occasionally arcing when they are open (40m - 10m).  The 
>arcing is apparently caused by an intermittent VHF parasite.  To find
>the 
>frequency of the parasitic oscillation, unplug the amp and measure the 
>resonance present at either side of the DC-blocker cap.  
>
>>I own the SB-200 amp. It operates fine on 40-10 meters. I have two well
>worn 
>>tubes. But the amp does not want to function properly on 80 meters. On
>80 
>>meters the amp indicates proper plate current but very low grid
>current. 
>>On 80 
>>meters the amp puts out a minimal 150-200 watts as indicated on my watt
>
>>meter and 
>>then drifts down while exciter power is applied. Any thoughts on
>diagnosing 
>>the problem or leads I might pursue? 
>>
>>Help,
>>Don
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>>
>
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