Interestingly while over in england for the weekend installing My wifes K3 I had a similar experience
I was interfacing the new DEMI 70MHz transverter which needed 5W drive at 10m So i set up the transverter to use the antenna 1 connector. When producing 5W the K3 thought the SWR was 4.5 to 1. Inserting an swr meter between K3 and xverter showed that the swr was 1.1:1 as an experiment I engaged the atu, which not surprisingly convinced the k3 the swr was 1:1. The swr meter still showed 1.1:1 I then put the ATU into bypass mode and this time it showed swr of 1.1:1 rather than 4.5:1, which didnt make sense Dave G4FRE > > Message: 10 > Date: Wed, 5 May 2010 14:31:29 +0100 > From: "Geoffrey Downs" <geoff...@downs.globalnet.co.uk> > Subject: [Elecraft] K3 - SWR on Tx Gain Calibration > To: <elecraft@mailman.qth.net> > Message-ID: <aaf7700462664dbf8edbdfb1b6173...@geoff> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > For some time I've been puzzled that, when doing a TX gain calibration > either manually or with the utility, the SWR displayed was 1.0:1 on all > bands except for 10m where it was 1.5:1. Yesterday my K3 (Ser. No. 266) had > a meeting with a K3 (slightly earlier Ser. No.) belonging to David G4DMP > (the owners met too!) and we found that his K3 was the same. > > Now here's the interesting thing. During tx gain calibration a 50 ohm dummy > load is used and the ATU is in bypass mode. As an experiment David put his > K3's ATU in circuit on 10m and pressed ATU Tune - result (unsurprisingly) > 1.0:1. He then put the ATU back into bypass mode and held Tune as one would > do in a tx gain calibration. Hey presto - 1.0:1! My K3 behaved in exactly > the same way and now always displays 1.0:1 on 10m into the dummy load with > the ATU in bypass mode. > > Presumably this is something to do with the ATU not being out of circuit > when in bypass mode. > > 73 to all > Geoff > G3UCK > > > > ------------------------------ > > Message: 11 > Date: Wed, 5 May 2010 08:39:34 -0700 (PDT) > From: lstavenhagen <lstavenha...@hotmail.com> > Subject: Re: [Elecraft] K3 - SWR on Tx Gain Calibration > To: elecraft@mailman.qth.net > Message-ID: <1273073974914-5009531.p...@n2.nabble.com> > Content-Type: text/plain; charset=us-ascii > > > For what it's worth, I definitely can't replicate this on my K3. The ATU is > definitely is bypassed when I select bypass on 10M (in both ANT sockets). > Do you hear the relay clicking when you switch back and forth between bypass > and inline? > > 73, > LS > W5QD > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/K3-SWR-on-Tx-Gain-Calibration-tp5008783p5009531.html > Sent from the Elecraft mailing list archive at Nabble.com. > > > ------------------------------ > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/elecraft > You must be a subscriber to post. > Elecraft web page: http://www.elecraft.com > > End of Elecraft Digest, Vol 73, Issue 5 > *************************************** ______________________________________________________________ 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
