I had an antenna for 160m that had a fairly high SWR at the feedpoint, but was easy to match to 50 ohms with a series inductor less than 30 feet further down the line toward the shack. I put a common mode choke per K9YC's designs at the antenna feedpoint, though, and even though it was actually two chokes in series (two large cores with separate windings) that should easily handle 5 KW under matched conditions, at 1.5 KW it heated up in less than two seconds to put the QRO Tech HF-2500DX amp into a fault. I could have moved the choke to the shack side of the matching inductor, but I decided it was best to just fix the antenna. No problems after I did.
Common mode chokes don't need high saturation current to get hot (and that's rarely the problem anyway) ... high SWR voltages work just fine for that. And at high power it can happen in a very brief period of time. Everyone stay safe, Dave AB7E > ______________________________________________________________ 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]
