[Lowfer] 2200 m WSPR - Puzzles

[N1BUG]

John,

I notice what appears to be a local interference line right on the
lower edge of WA9CGZ's WSPR signal. I have observed that WSPR often
has trouble decoding when a weak but steady (or nearly steady)
narrow band signal is somewhere within the WSPR tone spread. I have
seen it struggle even when the interference is much weaker than the
WSPR signal, as appears to be the case here.

I offer this only as one possible explanation. It might be
interesting if WA9CGZ were to QSY up 2 or 3 Hz and see if your
decodes improve. This assumes you always have that inference line on
that precise frequency, which I have no way of knowing.

I often have such issues with 2E0ILY, as his 137.550 frequency is
plagued by intermittent interference here.

Paul N1BUG


On 10/21/18 5:18 PM, JD wrote:
> I've got two mysteries at the moment. The first I'm not sure anyone has a
> good answer for (WH2XXP has been coming in at distinctly lower level in
> mid-day than used to be the case), but a couple of you might be able to
> help with the second one.
> 
> WA9CGZ came in a couple of times last night , but only twice, so I didn't
> think it would be a regular here. But apparently it is--except it doesn't
> decode, despite having a signal that is visibly clearer than XXP! (That's
> a benefit of having a couple of Argo instances going. One drawback of
> using WSPR in isolation as an indicator of propagation is that the signal
> may be getting through fine, strength wise, but not decoding for some
> other reason than SNR. Tou won't know that unless you're using other tools
> simultaneously and comparing results.)
> 
> The way I know it's WA9CGZ is from finding it on the same frequency in my
> decodes from last night, then searching for decodes of the call from other
> reporters...who still were copying him this afternoon! Most notably,
> WA3TTS and N8OOU.
> 
> Mike and/or Mike, could you check your WSPR windows or the ALL_WSPR.TXT
> file and see whether his dT value is near the ±2 second mark this
> afternoon? Unfortunately, that's one parameter the WSPRnet database query
> does not show. It indicates his drift is negligible, but gives no clue
> whether timing may be marginal.
> 
> This post has a file attachment showing the perplexing signals:
> http://lwca.org/mb/msg/8439.htm
> 
> Thanks.
> 
> John