As a counter to those who are asserting that SWR 1.5:1 is a good enough match for an antenna system I offer measured data for the KPA500.
At 14.005 MHz my KPA500, when connected to a 1.44:1 SWR load (R37, X9), had a PA dissipation of over 500 watts when producing 400 watts RF output. When the load was changed to 1.30:1 (R39, X3) the PA dissipation was about 410 watts. When the load was changed to SWR 1.07:1 (R49, X3) the PA dissipation was reduced to under 400 watts. (The plots are far more informative than a text description but I can't post them here). If you don't mind your KPA500 running hot, and are prepared to accept it shutting down with PA DISS fault, then 1.5:1 SWR may be good enough for you. I'd rather know the complex impedance of the antenna system load and avoid loads that result in high PA dissipation. 73, Andy, k3wyc ______________________________________________________________ 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
