Jim Brown-10 wrote > If I put KAT500 in BYP, the K3 often shows SWR's of 2 to 3. > > If left in AUTO, the mismatch is apparent in received audio. > > Without the KAT500, the antenna itself exhibits a 1.3 SWR consistently .
Many tuners add SWR even in bypass because the path through is not 50 Ohm. It is easy to check. Set a tuner in bypass, add a dummy load, and scan SWR. Usually SWR increases rapidly with frequency. Like 1.1 on 20m, 1.5 on 10m and 2.0 on 6m. This causes unnecessary matching when in automatic mode. The best way around this is to add a cap on the tuner input. Find that value that minimizes SWR on 6m. Usually it is 10-30pF. The cap needs to be big enough to handle power but not too big since the voltages are pretty low at low SWR (< 200V at 500W level). Ignacy, NO9E -- View this message in context: http://elecraft.365791.n2.nabble.com/KAT500-Tuning-on-6m-tp7576710p7576782.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
