John, I noticed the same high SWR in bypass mode on 10M the other day. I have the KPA500 and thus was wondering why the K3 was seeing up to a 1.7 to 1 SWR into the KPA500. So I got home from work today and tried your solution. I turned on the ATU and tuned into a 50 ohm dummy load. When I went back to normal operation in Bypass mode, the SWR into the amp was back to 1.1 to 1. Thanks for the tip.
Dave, N4QS ----- Original Message ----- From: "VK7JB" <[email protected]> To: <[email protected]> Sent: Monday, June 27, 2011 7:39 AM Subject: Re: [Elecraft] K3: SWR meter readings on 10m..mystery solved... > I've solved my mystery. > > I read in the archives that the KAT3 ATU is not completely out of circuit > in > "bypass mode". If I understand correctly, small values of L and C are > used > to remove it functionally, but there is stray reactance that might > contribute to the higher indicated SWR on some bands. > > So then I wondered if the KAT3 might need to be tuned at least once into a > 50 ohm load for the "bypass" state to be correctly determined. Made sense > in my imagination, and thinking on it, I realised I'd never tuned the ATU > into a 50 ohm load before. > > So I did that - tuned the KAT3 to the dummy load on the bands where it > previously indicated higher than expected in ATU bypass mode. I let it do > its stuff and find a match for the dummy load, then bypassed the ATU. > > Now, in ATU "Bypass" mode, the K3 reads 1.0:1 SWR into the same dummy load > that it previously showed as 1.5:1. Issue gone. > > 73, > John > VK7JB > > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/K3-SWR-meter-readings-on-10m-tp6519425p6520233.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
