Any cheap bulkhead connectors in the feed? I just got burnt by one on my radial plate....
Sent from my Verizon Motorola Smartphone On Mar 9, 2019 2:04 PM, Don Wilhelm <donw...@embarqmail.com> wrote: > > Peter, > > Isolate the problem to the amplifier. Get a high power dummy load if > you do not already have one. Run the amp at 1000 watts or more into the > dummy load. If the amp behaves the same as it does with the antenna, > then the problem is in the amplifier. > But if the amp behaves into the dummy load, look for marginal > connections to your antenna, PL-259 connectors not sufficiently > tightened, balun overload, arcing at either the center insulator or at > the end insulators. > There is very high RF voltage at the antenna ends, and it may be arcing > over the end insulators - don't overlook that possibility. > > 73, > Don W3FPR > > On 3/9/2019 1:50 PM, Peter Dougherty wrote: > > HI guys, > > I'm still having a serious problem on 80m with my KPA1500. > > > > With the amp inline I'm getting high reflected power fault everywhere below > > about 3675. My antenna (an inverted vee) is resonant at 3550, and the SWR > > is > > below 2:1 from 3500 to 3630. > > > > > > > > This was happening in the past as well, and prompted me to completely > > rebuild the antenna last summer. The antenna is fed with 100' of brand new > > Davis BuryFlex feedline, a brand-new 5kW-rated Balun Designs 1:1 current > > balun, new 12 AWG copper-clad steel wire, even new heavy ceramic > > insulators! > > > > > > Without the amp everything's fine. I can push 100W through to the antenna > > all day; the SWR LEDs on the amp (bypassed) show two green and that's it. > > It's fine on every other band, including 80/75 phone. > > > > > > > > With the amp in, If I drop the drive to 10W or less, the amp is happy and I > > get about 450 Watts out. But the instant I drive it with ~15 Watts (when > > the > > K3s kicks the high power module in, and I hear the internal relay click, I > > get the HI SWR warning and the amp faults. 100% repeatable. Doesn't matter > > if the tuner is in or out..there's NO way to get high power out of the KPA > > on 80 CW. > ______________________________________________________________ > 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 ______________________________________________________________ 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
