[Elecraft] Topband RF feedback problem

[Barry N1EU]

Yes, Stewart asks a good question.  As I reported previously, I had to
install an ICE 196 RF Limiter in the Beverage feedline to prevent my Acom
from generating "ArcFault" errors on 160M. 

73,
Barry N1EU



Stewart G3RXQ wrote:
> 
> Are you using a separate RX antenna ? There is a recognised issue
> with the KXV3 and insufficient isolation  that can give rise to
> spurious oscillations.
> 
> 73
> Stewart G3RXQ
> On Sun, 10 Feb 2008 21:43:55 +0100, Björn Mohr wrote:
>> I had my first weekend with the new K3 and bumped into a strange
> problem. It
>> actually took me a while to figure out what was going on. When
> keying up
>> with the amplifier in line on 160 I was not able to run more
> than 400 watts
>> before the SWR protection in both the amp and SWR meter kicked
> in, it all
>> happened in milliseconds as if arcing was going on somewhere. I
> thought I
>> had an antenna problem and went through the system without
> finding anything
>> strange. After some time I hooked up my MP and all was fine
> again, running
>> full power without a problem. That's when it hit me - RF
> feedback had to be
>> throwing my K3 off frequency and therefore tripping SWR
> protection and the
>> alarm.
>>
>> My setup has been working fine with the MP for over a year,
> never seen a
>> problem like this. A common mode choke is in line with the TX
> antenna and
>> most of the wiring used with the MP was used for the K3 except
> that power
>> where fetched from my 12 volt bus. The MP is a field model and
> gets its
>> power straight from the mains, same phase as the 12 volt bus.
>>
>> I would be interested to hear if anyone else had similar
> problems and found
>> a good solution.
>>
>> 73 de Björn /SM0MDG
>>
>>
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> 
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