HFU HF Underground
Loggings => HF Mystery Signals => Topic started by: BoomboxDX on June 05, 2024, 0353 UTC
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Over the past couple weeks I've heard a usually strong RTTY / FSK signal around 14001-14002 kHz in the 20 Meter Ham band. I don't have any radio that tunes more precisely, and even at that I'm not really great at zeroing an FSK signal, as I am never sure where to 'zero' it.
I'm sure it's not an overload product, and the signal propagates. It's varied in strength from S3 to S5 (on a scale of 0-5), and one morning it was MIA (which was during a morning when the 20M band was mediocre, propagation wise). I generally do my HF monitoring in the a.m., Pacific time, so that's when I hear it. I don't have an SDR so I can't post a waterfall or anything like that.
I was just curious as to whether anyone else in the Western US is hearing this during the morning hours. Obviously, it's an intrusion into the 20 M ham band, because the band plan calls for RTTY much higher in the band.
I have it logged in my most recent logbook starting May 26th, but I know I heard it before then. Anyone else hearing this, and any idea what the source of the signal is? Here in the NW US we sort of have a pipeline to Asia during the mornings, so my instant guess is that it's coming from Asia somewhere, but I could be way off in my guess....
It's sort of odd that the ham forums never mention intrusions like these much.
Monitoring equipment is a Realistic DX-390, Panasonic RF-B45, 30 ft. indoor wire up 20-25 feet. NW US.
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I'll add here that I haven't heard this RTTY on 14001~ for the past several mornings. It's possible it could be some sort of overload, although my Panasonic RF-B45 isn't prone to overload. And I'm not aware of any local RTTY utilities, or ones that would be so strong they'd propagate while overloading my radio.
I'll keep an eye out for it, though.
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Another week and I still haven't heard the mystery RTTY. Still am not certain it was an overload image, my Panasonic doesn't overload much, if at all. That said, I'm marking it down as a mystery and won't post more here unless I hear the station again.
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Another week and I still haven't heard the mystery RTTY. Still am not certain it was an overload image, my Panasonic doesn't overload much, if at all. That said, I'm marking it down as a mystery and won't post more here unless I hear the station again.
It wasn't overload, I heard this as well. Some sort of intruder signal.
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Another week and I still haven't heard the mystery RTTY. Still am not certain it was an overload image, my Panasonic doesn't overload much, if at all. That said, I'm marking it down as a mystery and won't post more here unless I hear the station again.
It wasn't overload, I heard this as well. Some sort of intruder signal.
Thank you for letting me know you heard it also. II guess I'll keep listening and seeing if it re-occurs.
If you're in BC, we're not too far from each other, and we both have a pipeline to Asia in the a.m......
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An Update: I've been hearing this intruder on 14002 over the past 8 hours or so, from 0528 (when the RTTY was strong, about S4 out of 5) to just now, 1210 UTC (5:10 a.m. local, Pacific time). The signal dipped into the static, just barely legible, around 0935 UTC.
It's been pretty consistent as RTTY though (or related FSK).
I've also heard a different RTTY signal at 14009 kHz, several times during the past several evenings. Earlier this a.m. (July 31) I heard the RTTY on 14009 at 0523, after which it put out a peep noise and then stopped. This also happened the a.m. of July 30th at 0530 UTC, and on July 26th UTC the 14009 RTTY was fairly strong, S4 out of 5, and it sped up its bit rate and then ended with a peep noise at 0525 UTC (10:25 p.m. local Pacific).
I'm not aware of all the amateur band plans world wide, but continuous RTTY doesn't seem to fit any amateur transmission procedures, and RTTY in the US is only slotted in above the CW band for the most part.
So I've got two mysteries, one on 14002 and the other one on 14009, which look like intruders. I'm still guessing Asia, due to the fadeout characteristics on 20M after 1 a.m. or so local time.
Receivers used have been DX-394, Tecsun PL-330, DX-398, all working off the same indoor, 25 ft second story wire. I'm in Western WA state.
Any ideas out there?