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List:       elecraft
Subject:    Re: [Elecraft] KPA500 REFL HI fault
From:       Robert Redmon <k5sm.bob () gmail ! com>
Date:       2011-09-30 21:11:20
Message-ID: 4E863078.3010404 () gmail ! com
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Thanks to Don, Rick, and Johnny for the suggestions. I had the 
opportunity to closely inspect the 80 meter antenna today after running 
a dummy load at the antenna switch and found a carbon trace on an 
insulator at the feed point.  Mystery solved.

73, Bob K5SM

On 9/29/2011 7:50 PM, Don Wilhelm wrote:
> Bob,
>
> I suspect a fault in your antenna system that is OK at 100 watts, but 
> does something "funny" (like perhaps arc over) when 500 (or 250) watts 
> is applied.
>
> Does the same thing happen into a dummy load?  If so, then it is a 
> KPA500 problem, but if OK on a dummy load, take a good look at your 
> antenna system.
>
> 73,
> Don W3FPR
>
> On 9/29/2011 8:43 PM, Robert Redmon wrote:
>> I put my KPA500 on 80 meters for the first time this morning, and it
>> faults after several characters. SWR as shown on both the K3 and the
>> KPA500 is 1.3:1. I reduced drive to 11w (250w out), and it still does
>> it. The first few cw characters, swr looks fine, but if I pause a bit
>> and hit the key again, swr jumps above 5:1 and the amp shuts down with a
>> "refl hi" fault. If I run the K3 barefoot at 100w, the swr is steady at
>> 1.3:1 no matter what I do. Anybody know what is going on?
>>
>>
>
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