[Elecraft] KAT 500 Loses Match

[Bob McGraw]

 From your description, something in the antenna system, coax, 
connector, balun, antenna is heating and changing value.   I doubt it is 
the radio, or the amplifier, or the tuner.

That antenna is rated at 250 watts PEP.  Sure bet you are exceeding the 
power rating with the KPA500 running.

73

Bob, K4TAX



On 1/13/2024 3:58 PM, elecraft-request at mailman.qth.net wrote:
> Message: 5
> Date: Fri, 12 Jan 2024 23:28:09 -0600
> From: "Michael Reynolds, NO6O"<Michael at NO6O.com>
> To:elecraft at mailman.qth.net
> Subject: Re: [Elecraft] KAT 500 Loses Match
> Message-ID:<fc07b444-9571-47e7-9629-846473012361 at NO6O.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> 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