[Elecraft] K3 spurious radiation?

[Thomas Horsten]

Hi John,

I had this happen to me a few days ago where I was calling CQ on 7.015 and
was spotted on 14.0614 by Tim KQ8M's skimmer. I emailed KQ8M to ask him if
there was a problem with his skimmer. He replied that he wouldn't rule out
that the problem was in his Rx setup, but it was tuned to 20m.

Now I was running through the linear and an ATU, and I can't see any
logical relationship between the two frequencies, so I'm leaning to the
theory that his receiver was the culprit, although I did find it very
strange.

I think a lot of RBN skimmers use SoftRock receivers, and I'm guessing that
if his VFO was tuned to 14.050 using the 2nd harmonic of a 7.025
fundamental, it would kind of fit, but I'm still surprised that my 300W
signal to an inverted V was 6dB over the noise on the wrong band in Ohio,
3800 miles away on the other side of the Atlantic... I'm not sure exactly
because I don't know what receiver he was using, but it did have me puzzled
and when I saw John's post I thought I'd mention it.

Here's the spot in question:

 de dx freq cq/dx snr speed time KQ8M<http://www.reversebeacon.net/qrz/KQ8M>
 M0TRN <http://www.reversebeacon.net/qrz/M0TRN> 14061.4 CQ [LoTW] 6 dB 22
wpm 1952z 22 Jan S50ARX <http://www.reversebeacon.net/qrz/S50ARX>
M0TRN<http://www.reversebeacon.net/qrz/M0TRN>
7015.0 CQ [LoTW] 14 dB 21 wpm 1952z 22 Jan
W3LPL<http://www.reversebeacon.net/qrz/W3LPL>
 M0TRN <http://www.reversebeacon.net/qrz/M0TRN> 7015.0 CQ [LoTW] 14 dB 19
wpm 1952z 22 Jan W3LPL <http://www.reversebeacon.net/qrz/W3LPL>
M0TRN<http://www.reversebeacon.net/qrz/M0TRN>
7015.0 CQ [LoTW] 14 dB 19 wpm 1952z 22 Jan

73, Thomas M0TRN

On 24 January 2012 13:08, John/K8AZT <k8azt-k3 at sbcglobal.net> wrote:

> I have not been monitoring this mail list much recently so I apologize if
> this
> subject has been discussed previously.
>
> I like to monitor the reversebeacon.net website while calling cq or just
> monitoring looking for a qso.  Recently I have discovered a situation
> which has
> me puzzled and I am hoping someone here might be able to give me some
> insight
> what might be happening.
>
> When calling cq (CW) on 7.0 MHz cw,  I see several hits on the reverse
> beacon
> website on 7.0 MHz, however I have also seen a couple stations allegedly
> hearing
> me on 10.1 MHz (2 occurrences) and a station hearing me on 28 MHz bands (1
> occurrence).  I am hoping this is a problem with the skimmers, but want to
> check
> out if there is anything which might not be right with my K3 and/or antenna
> which might be generating unwanted radiations.  At the moment I do not have
> exact frequencies where I was being monitored.  I just thought someone
> might
> have a suggestion where do I proceed.
>
> At the moment I do not have access to a frequency analyzer, but hope I can
> find
> one to borrow locally.
>
> Thank you for any suggestions/comments anyone in the reflector might have.
>
> 73,
> John/K8AZT
> K3/ SN 1693
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