Sounds like my shack when I had RF problems. Strange SWR was one of my problems also.
One thing I found is that I need to wind a big choke on the power leads into the K3 to stop a lot of my problems. It was the last thing I did to fix issues. I wish I would have know to start there :-) ~73 Don KD8NNU On Sat, Feb 18, 2012 at 6:09 PM, Ken wrote: > On Feb 18, 2012, at 5:43 PM, Don Wilhelm wrote: > >> Rick and all, >> >> Look for something in the antenna system that is arcing over above >> the 80 watt level (or whatever level the problem starts). Check >> every junction in your antenna system. Your workaround may be OK, >> but the real fix may increase your antenna efficiency. > > > That's where I first started. I replaced the ancient twin lead with > new open wire. No change. I replaced the 4:1 balun with a new 1:1 > balun. No change. > > I replaced the coax to the balun. No change. I inspected the center > insulator, that's a block of quarter inch PVC with everything > separated at least two inches. I checked the end insulators. They > look fine and they are tied to Dacron line. The ONLY thing I didn't > change is the antenna wire ;-) > The antenna is in free space with the closest object being the antenna > mast a foot away. > > What did stop the problem is changing rigs (to a TS-440) or changing > the antenna tuner (to the Palstar). What's in common with the > problem? The K3. > > >> >> The other situation that will cause "bad behavior" above a certain >> power level (and on a particular band) is common mode RF coming in >> from the antenna and its feedline. The SWR sensing circuits may "go >> crazy" in the presence of too much RF voltage. In this case, the use >> of common mode chokes at the antenna, and possibly at other points >> along the feedline may be what it takes to "tame the beast". > > > Now that sounds like a possibility. > Ken WA8JXM > ______________________________________________________________ > 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
