That antenna is rated for 250 watts, which is most likely the cause of the problem. This is common, we upgrade from low power to high and don’t realize that we need to upgrade out antenna system as well. For use with the KPA500, you should replace it with an antenna with a higher rating. These are easy to fabricate - I am currently using a 110 foot long dipole with ladder line feed which is tunes quite nicely by the KAT500, and has no issues with either of my KPA500s. Just take a look at examples in the current ARRL Antenna book for better info.
73! Jack, W6FB > On Jan 12, 2024, at 11:28 PM, Michael Reynolds, NO6O <mich...@no6o.com> wrote: > > 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-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> on >> behalf of Ken WA8JXM <wa8...@gmail.com> >> Sent: Friday, January 12, 2024 5:52:52 PM >> To: elecraft@mailman.qth.net <elecraft@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 >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to k9...@live.com >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to mich...@no6o.com <mailto:mich...@no6o.com> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net <http://www.qsl.net/> > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to jackbrin...@me.com <mailto:jackbrin...@me.com> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
