The difference between an SWR of 1.3 and 1.1 is minimal. There is probably some calibration error between the KX3 and MiniVNA. There is also stray C & L in each, so that may contribute to the difference. I don't know if a forward/reverse power calibration is approved for the KX3, but it's not shown in the owner's manual.
Very low power levels might also be a problem. At low power levels, the ADC that reads the directional coupler output is working at a low range, with reduced resolution (small number of ADC output bits compared to a higher power level). Some call this "resolution error". I've heard it said that SWR less than 2 is pretty fair and within operating limits of most transmitters. The KX3 is no exception. Just did a comparison at 5W between KX3 and LP-100A (factory calibrated). The KX3 shows 1.4 SWR and the LP-100A shows 1.7, both done on the same dummy load, with the ATU in bypass. I wouldn't worry about the difference. In actual power terms, the reflected power is extremely low in either case. 73, matt W6NIA On Sun, 29 Dec 2013 22:26:24 +0100, you wrote: >My KX3 #4475 shows SWR 1.3 when I press tune and send into a dummy load. >I checked cable and dummy load with a MiniVNA pro and my K3, both show perfect >SWR of >1.0 and 50 ohm. The KX3 has no tuner built in. > >Any hints where to look? > >73! de Werner OE9FWV ______________________________________________________________ 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
