[RFI] 20 Meter Interference
K9MA
k9ma at sdellington.us
Tue Feb 23 21:25:09 EST 2021
The spectra images didn't come through, so here are the links:
http://sdellington.us/hr/RFI/20m_K9MA.jpg
<http://sdellington.us/hr/RFI/20m_K9MA.jpg>
http://sdellington.us/hr/RFI/20m1_K9MA.jpg
<http://sdellington.us/hr/RFI/20m1_K9MA.jpg>
73,
Scott K9MA
On 2/23/2021 7:46 PM, K9MA wrote:
> I've recently started seeing this signal on 20 meters, probably local,
> as it is present late at night when the band is dead. It is a swept
> signal, typically starting at about 13.625, sweeping upward to a sharp
> cutoff at about 14.125. The total sweep seems to be about 500 kHz. The
> sweep slows down near the upper limit and seems to dwell there. Sweep
> repeats about once per second. It seems to be amplitude modulated
> during the sweep, so it shows up as a series of pulses on the
> waterfall display. While the frequency range seems fairly stable, it
> does move around a bit. I can't tell whether the frequency change is
> systematic or random.
>
> In the attached images, the blue trace is the peak signal, accumulated
> over many sweeps. The yellow one is the actual signal, without
> averaging, which I caught near the upper end of the sweep. The
> waterfall shows the pulsed modulation. Resolution bandwidth is about
> 440 Hz.
>
> Any idea what this might be?
>
> 73,
>
> Scott K9MA
>
--
Scott K9MA
k9ma at sdellington.us
More information about the RFI
mailing list