[Elecraft] KAT 500 Loses Match

[Michael Reynolds, NO6O]

Greetings,

I joined this list today, after sending a message to Elecraft support, 
describing a similar problem.  I have an Icom IC-7610, with the KPA500 
and KAT500, and my SWR spontaneously climbs into the red sometimes 
during transmissions.  It takes some effort to correct it, and I 
typically lose a QSO in the process.  The relays go nuts trying to 
re-tune, and sometimes produces a fault condition. Usually, I can 
correct it by restarting both the amplifier and tuner.  I have a Comet 
CHA-250HD, which has a almost a flat 1.1 SWR from 80m to 6m.  I don't 
need a tuner while barefoot.  However, when I first hooked up the 
KPA500, the SWR was not flat, and added the KAT500 this week, which led 
to my SWR issue.

I hope the cause and resolution can be determined.

Michael
NO6O


On 2024-01-12 10:36 PM, Bill Johnson wrote:
> Good advice
>
> Bill
> K9YEQ
> ________________________________
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> on behalf of Ken WA8JXM <wa8jxm at gmail.com>
> Sent: Friday, January 12, 2024 5:52:52 PM
> To: elecraft at mailman.qth.net <elecraft at mailman.qth.net>
> Subject: Re: [Elecraft] KAT 500 Loses Match
>
> It's possible that something is arcing and, of course changing the  tuning.
>
> Do you have the internal tuner in the K4?  If so, does it behave the
> same way?
>
> Why do you have the amplifier running?  30m is as restricted power band.
>
> If you leave the amp and tuner out of the circuit and transmit with the
> K4 directly, does the SWR meter stay steady, or does it fluctuate at
> full power?
>
> Ken WA8JXM
>
> Why is the amplifier connected?  30m is a restricted powerband.
>
> On 1/12/2024 4:46 PM, Paul Ecker wrote:
>> I am experiencing a new problem for me, with my KAT 500. So far I've
>> noticed this issue on 30M. I am using a dipole cut only for 30M with an SWR
>> of 1.2 to 1.3 max SWR across the band. I “trained the tuner” at 20khz
>> segments on 30M.
>>
>> Setup is K4D, KAT 500 & KPA 500. Win 10 pc.
>>
>> Running CW, I can start transmitting and all is fine- my LP100A is showing
>> 1.2 SWR and am getting max power out of the radio. Then all of sudden the
>> SWR jumps to >9.0. The KAT starts chattering and finds a new match. But if
>> I start transmitting again – pwr out is only about 10 W at that new match,
>> and eventually the tuner becomes untuned again. Sometimes, it will then
>> hold the tune but still only getting abt 9-10w power out. The issue occurs
>> with KPA500 both on and off.
>>
>> Does this sound like a KAT 500 problem or maybe an RFI problem.
>>
>>
>> 73 Paul
>>
>> w2eck
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