[Elecraft] K3 SWR Question3

[Barry Simpson]

Hi Ed

I recall having had a similar experience with my K3 some years ago,
although it wasn't on 40m. I think it was either 10 or 12m and related to
an antenna connected to the ANT 1 socket.

Eventually I tracked it down to having previously had an antenna connected
to the ANT 2 socket and having used the ATU in the K3 to tune it at that
time although I think that there was no antenna on ANT 2 when the problem
cropped up.

I believe that the feed through between ANT 1 and 2 sockets was sufficient
to give a false SWR reading on the K3.

It might be worth investigating this and possibly swapping over your
antenna/dummy load to the ANT 2 socket to see what happens.

I think I eventually just retuned the ATU on ANT 2 with a dummy load in
place and the problem went away.

Good luck.

Barry  VK2BJ

On Mon, 21 Jan 2019 at 04:17, Ed G <ed.n3cw at gmail.com> wrote:

> Hello,
>      My K3 is exhibiting some SWR meter behavior I don’t quite understand.
> To eliminate any possible effects of antennas or cabling, I hooked a
> Palstar DL2K dummy load directly to the K3 antenna connector. All bands
> except 40 meters seem fine, with SWR reading as you would expect with a
> dummy load. The anomaly I am seeing is that SWR as shown on the K3 meter
> looks fine at 7.01 MHz (approx. 1.2:1), but as I go up in frequency, the
> SWR as shown on the K3 meter rises. When I transmit into the dummy load on
> 7.298 MHz, the K3 meter reads almost 3:1.   I can switch in the K3 internal
> tuner and bring the SWR down to 1:1.
>      I also tried an older Cantenna dummy load with the same puzzling
> results.  Any ideas as to what may be causing this 40 meter only problem?
> I first noticed this problem during NAQP SSB when using my Steppir, which
> of course retunes itself as I change frequency. When going from the low
> part of the phone band to the high part on 40 meters, I noticed SWR
> increasing on the K3 meter, even though it was not increasing and stayed at
> 1.2:1 on my inline LP-100A.  The K3 also started to fold back power.  That
> prompted me to do the further testing with the dummy load as I discussed
> above.
> --Ed—
>
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