Gang, I was surprised last night when I got a descent low SWR tuning my 80-meter (ladder-line fed into 4:1 balun) dipole on 160 meters. I have had the KAT500 for a couple of months and I never bothered trying it on 160 meters because on all previous attempts with other manual tuners I have failed to get a good match.
But, last night, just as a lark, I switched up to 160 meters and gave the KAT500 a try. Sure enough it found a match of 1.05:1 at 1900 KHz with the Bypass VSWR reading about 17:1. Given I have most of the transmission line in lower-loss ladder line helps with the losses to the antenna with that high bypass SWR. This was at 100 watts out from the K3. Now, I decided to give a try with the KPA500 in-line at about 475 watts and the best I could get is about 4:1 tuned SWR. Now, I am not quite sure I understand the dynamics of the KAT500 with higher power. This is what I did. I tuned at 20 watts to the 1.05:1 SWR (bypass was ~17:1). At 100 watts, my LP-100A was still reading about 1.1:1 SWR. But, when I turned on the KPA500 (switched out of standby) the reading was roughly 4:1 with a fault on the KPA500. Question, how does the higher power affect the match of the KAT500. I understand how higher power might stress the KAT500 with maybe arcing or something but I don't understand why the match actually changed unless that higher power caused some change in the KAT500 capacitor or inductor components. 73, phil, K7PEH ______________________________________________________________ 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
