I had a similar problem but only on 160m. would work fine for a few minutes at full power, fine at reduced power. After much hair tearing discovered that it was a voltage transformer in an external coupler heating up and losing inductance, effectively shorting the feeder. Cured by using a larger toroid in the coupler.
Brian G3VGZ "j...@kk9a.com" <j...@kk9a.com> wrote: > A dummy load may verify that the KPA/KAT are working properly. I am > guessing that something is arcing in your antenna system. Perhaps water > ingress. Have you run high power into it with a different amp? > > John KK9A > > > > On March 12 Alan Lambert wrote: > > I recently acquired a KP500/KAT500 for use with my Kx3/KXPa100. I know the > person I bought it from well and I am 99.9999% sure it is not an issue > with the amp or tuner. > > I was making some notes (a chart) for input to output power levels, > mostly just to ‘get to know’ the amp a little better. At the time of > these issues, I was on 80m SSB and the Kat500 was showing 1:1 / 1.2:1. > > The output watts I have listed below are not ‘actuals’ I’m just recalling > them from memory so may be off a few watts. > > I set the Kx3 to 8w and called “test test test 1 2 3 kn4bbc” I showed > ~80w out with a 1:1 to 1.2:1 SWR.. GREAT! > > Moved up to 9w and got 100w out… same SWR – more Great! > > 10w I got 175w same SWR – sill looking good! > > 11w I got 250w same SWR – Awesome! > > Now this is where the problem comes in. > > I set to 12w… As I starting calling my “test test test 1 2 3…” At first > things looked great..I was getting 300w same SWR but then suddenly I get > high SWR followed by “High Refl” on the KPA5, fault light comes on and I > get warning tones. > > So I tuned the KAT500 again and tried the whole thing again with the same > results. > > Gear wise: > > KX3/Kxpa100 with ATU disabled > KPA500/KAT500. > > Ant1 on Kat500 > 1ft LMR400 jumper > 1:1 ATU Current Balun > 225 feet > of 450 ladder line > a ½ wave 80m center fed, inverted V dipole. Center > point is ~90 feet off ground. > > The Balun is a Balun Designs Model 1161 > > The shack is on 2nd floor in middle of the house and has no exterior > walls. > > The ladder line starts in the shack, there is about 2 feet of in the > shack then enters my attic space thru and opening in a sheetrock wall. > Inside the attic space there is a long slow, wide loop about 50 feet long. > I was careful to keep it away from metals and it does not cross itself > however some of it is lying on top of plywood. From there its exits the > house in the ridge cap at the tip top of the roof at about (40 feet off > ground) The ladder line then hangs from a rope that runs from the eve to > the tree line about 175 feet away which is where the center point of the > dipole is. In short 175 feet outside 50 feet inside. > > > Ideas of what my problem might be? > > ______________________________________________________________ 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 > gro...@planet3.freeuk.co.uk > -- Brian D G3VGZ Yarm England ______________________________________________________________ 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
