John - I've got an AL-811 but this (luckily) has not happened to me. I suggest a call to Ameritron / MFJ, as it sounds like a component in the input circuitry in the amp has gone flakey: able to withstand low amounts of RF but fails under higher power. I had an issue with my AL-811 not being able to load up on 80 meter CW - they were extremely helpful on the phone.
Jim / W6JHB On Aug 9, 2013, at 8:37 AM, John Shadle wrote: > Hi all, > This could be tangentially related to a K3 issue, or maybe K3 experts can > give some insight here. FYI, when I am not using the amp, I can get 100W > from my K3 with no problem. Please keep reading... > > I have been using my AL-811 (not new, but new to me) successfully at 500W > for the past few weeks. Recently (actually, the second time this has > happened), my fuses both blew and I replaced them. Since I replaced them, > behavior has not been typical. I can't get anything over 200W (most is in > the 175W range). I use a tuner after the amp, and I know that the antenna > is matched quite well to the amp, but my SWR meter on my rig (K3) is > showing a high value. > > When I tune up at 20-25W I can get about 100W out from the amp. When I move > to 50-65W I get < 200W. And there is clicking. I can't tell if it's a relay > or if it's something else. > > So, the main issues are > 1. High SWR from the rig to the amp (when the antenna is < 2:1 SWR to the > amp) > 2. Low power from the amp to the antenna > > Happy to provide other information if folks have ideas on where to look. > > Thanks. > -john W4PAH > ______________________________________________________________ > 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
