Thanks for the explanation Joe - that makes sense now and indeed after doing as you suggest all is 'normal'. The "soft" bypass concept isn't what I'd call intuitive so my only suggestion would be an explanatory footnote to this effect in the manual, always assuming I haven't missed it....
Who says you can't teach an old dog new tricks? 73 and thanks, Stewart, GW0ETF (Original owner of K3 #145) Joe Subich, W4TV-4 wrote: > > > Stewart, > > The K3ANT does not do a "hard" bypass. Instead it sets the > tuner to the memorized 50 Ohm : 50 Ohm position. > > Since the tuner memories are "by band" and "by antenna" - plug > the dummy load into the ANT 1 position, enable the tuner and > hit the "ATU Tune" button. That will "teach" the tuner the 50 > Ohm setting for ANT 1 and you won't see the issue in the future. > > 73, > > ... Joe, W4TV > > On 6/11/2010 2:14 PM, Stewart Rolfe wrote: >> No doubt the recent Es propagation has brought the following >> behaviour to my attention...it's only evident on 10m for some >> reason:- Screw in a PL259 type dummy load into ANT1 (KAT3) and >> deselect ATU. Press TUNE (10w) and the indicated swr on the K3 is 1.7 >> to 1.8. Change dummy load to ANT2 and select and the indicated swr is >> now 1.0...! I've swapped the antenna leads on the KAT3 board to >> determine it's something to do with circuitry around the antenna >> relay and not PL259 sockets/interconnecting leads but according to >> the schematics each path is equivalent. Furthermore an external swr >> meter placed between dummy load and K3 indicates 1:1 on *both* ANT 1 >> and 2 so it seems to be something to do with the way the radio is >> sensing the swr between the two antenna sockets. I'm not at all hung >> up on swr but why the difference between the 2 antenna inputs - >> strays in the relay or surge arrestors? It also looks like the radio >> is 'thinking' about the power output when the swr indicates 1:1.8 and >> above and may cause power variations....? Thoughts?? 73, Stewart >> Rolfe, GW0ETF (K3 #145) >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ > 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 > > -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Odd-SWR-readings-ANT1-v-ANT2-tp5169157p5171025.html Sent from the [K3] 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
