*John, Checked my emails later than normal for the day and so I see you have had an issue like I had once except i discovered the jumper was indeed faulty.
Glad to see you got it sorted. 73 * On 8 October 2012 08:31, <[email protected]> wrote: > > > Group, > > I think I've discovered the cause: I noticed the SWR seen by the > K3 at 52.00MHz is 1.2:1, whereas it's 10:1 on all other bands. This > was shown on the K3 SWR meter and confirmed with my antenna analyser > at the K3 antenna connector. I did some detective work and > discovered that the length of the (short) jumper cables connecting the > K3, the sensor of my LP-100A and the dummy load was either having a > transformer effect or otherwise introducing stray reactance. The > results was a less than perfect 50 ohm match on 52.000MHz. > > I changed the length of the jumper cables just a little (swapping > them out with others of different length), and the SWR seen by the > K3 came down to 1.0:1 @ 50Mhz and the Tx Gain calibration routine then > ran perfectly. > > I'm using LMR-240 ultraflex jumpers and individually, connected to > the dummy load, they check out OK. It's something about the total > inter-connect length at 50Mhz. > > Thinking back, I suspect I've changed the in-shack jumper > arrangements since the last calibration. > > Thanks for everyone's help. > > 73, > > John > > VK7JB > > > ______________________________________________________________ > 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 -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ 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
