Ronnie, I’m kinda late to this dance, but did want to toss in my thoughts. I assume you are running a length of beefy coax from the back of the KPA1500 to the balun. I do the same with my KPA500/KAT500. About 10 feet of 9913 coax to the Balun Designs box, then 110 feet of 600 ohm line to the antenna feed point. I initially had a very ugly SWR on 20 meters that the KAT500 balked at; the other bands were fine. Changing the length of the coax between the tuner and the balun cured the problem - I went from 20 feet (a convenient piece of coax I had lying around) to 10 feet. If you’ve got some other lengths of coax available, you might want to try switching them in / out - might be easier than chopping the ladder line.
73, Jim / W6JHB > On Sep 2, 2020, at 6:06 PM, Jim Miller <[email protected]> wrote: > > Have you measured the impedance presented to the amplifier with an antenna > analyzer? > > Jim ab3cv > > On Sep 2, 2020, at 9:03 PM, Adrian <[email protected] > <mailto:[email protected]>> wrote: > > Ronnie, well done. Moving to a different ratio balun is a smart obvious move > towards obtaining a better match, > > especially at higher power maintaining insulation specs required. > > From curiosity what was the model number of the BD 4:1 balun you had > initially please ? > > >> On 3/9/20 10:03 am, Ronnie Hull wrote: >> The original thread has gone off on some tangents. I truly appreciate all >> the suggestions. >> >> I seem to have cured the problem! >> >> ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder >> line. The ladder line was hooked to a Balun Design 4:1 ( as recommended by >> the seller of the antenna). The antenna would be matched great in 160M by >> the internal ATU in the K3 but with the KPA1500 inline it all went north >> really fast, resulting in the 1500 faulting out >> >> Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a >> hell of a lot better but the KPA1500 still could not match it better than 9:1 >> >> Mind you this antenna matches superb on other bands with the KPA1500 >> >> Also the KPA1500 works great into a dummy load so I knew the issue was the >> antenna or part of it >> >> Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked! >> The KPA1500 matches to 2.5:1 which is good enough for now. >> >> Next I will experiment with the 600 ohm ladder line length. Right now I’m >> using 57’. I will add 10’ tomorrow and see what shakes out and will let you >> fellas know >> >> Thanks for all the help and suggestions! >> >> Ronnie W5SUM >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > <http://mailman.qth.net/mailman/listinfo/elecraft> > Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> > Post: mailto:[email protected] <mailto:[email protected]> > > This list hosted by: http://www.qsl.net <http://www.qsl.net/> > Please help support this email list: http://www.qsl.net/donate.html > <http://www.qsl.net/donate.html> > Message delivered to [email protected] <mailto:[email protected]> > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
