Messages

1

HF Mystery Signals / Re: What is this digital signal around 1.903 Mhz

« on: February 14, 2025, 2328 UTC »

as txtune said it's been going on for a while. I first decoded wspr there 12/11/2023
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I've since tried wspr but was unable to decode. that's with wsjtx 2.7.1 and I've tried fst 4w @120, but no luck.
maybe something with raspberry pi?

I had forgotten about that.
You spotted some WSPR signals on 1.904xxx back in December:


This 'new' signal must be something other than WSPR.

2

HF Mystery Signals / Re: What is this digital signal around 1.903 Mhz

« on: February 14, 2025, 2251 UTC »

Maybe WSPR?  That's not the standard 160m frequency for it, but the the TX time is about 110 seconds.
https://www.sigidwiki.com/wiki/WSPR

That was our first guess, but I cannot get this one to decode when monitoring for WSPR.

The Wiki says WSPR is 6 Hz wide, this one is a bit wider. With that being said, I could be measuring incorrectly.

There are a few other modes on sigidwiki that look close, Lentus for example. FSQ also looks close, but it is listed as 300 Hz wide. FT8 looks very similar and the bandwidth is close.   

3

HF Mystery Signals / What is this digital signal around 1.903 Mhz

« on: February 14, 2025, 2006 UTC »

This signal has been present in the early morning and late evenings for the last couple of months, that I know of. I am receiving these in the north Texas region.

It appears to be 25 - 40 Hz wide. There is a red circle drawn around a notch filter in the first image, that filter is 25 Hz wide.

The signal lasts roughly 120 seconds. Sometimes they are ten minutes apart, but not consistently.

I am sure this is simple for someone who knows digital signals.
Thanks for taking a look!