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Loggings => HF Mystery Signals => Topic started by: BoomboxDX on July 17, 2024, 1919 UTC

Title: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: BoomboxDX on July 17, 2024, 1919 UTC
I've heard this several times over the past week, late nights PDT, noticing it after 0800 UTC when I tune into the 20 M band to see if anything is happening.

The noise is just outside the top edge of the 20 Meter Ham band. Can't find any record of what sort of station this might be, although I'm not up on ute signal sleuthing.

It sounds like a jet engine, and it propagates, so I'm pretty certain it isn't RFI. It seems to occupy a wide swath of spectrum, but it's centered on 14356-14357.

Any idea what this is? It's a continuous jet noise. Can't be a jammer, because there is, or was, nothing to jam there.
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: tiNG on July 19, 2024, 0613 UTC
Hi.

Any recording would help to identify your UNID. Do you have one?

73's

Thomas
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: BoomboxDX on July 19, 2024, 1259 UTC
I have a 10 sec. phone MP4 vid I took of it, last night. Not able to post it here, though. It probably wouldn't help, as phone clips often sound like junk.... It's a phasing jet noise, and occurs after midnight local... It doesn't strike me as RFI because the signal level is not always consistent. If you remember how the 'jet noise' utilities sounded in the 1960s and 70's (some sort of multiplexed communication mode), it's similar.
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: BoomboxDX on July 21, 2024, 1950 UTC
FWIW, it hasn't been on frequency the past couple a.m.'s. Anything more I hear, I may post here. Otherwise, done here.
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: BoomboxDX on July 25, 2024, 0028 UTC
Hi.

Any recording would help to identify your UNID. Do you have one?

73's

Thomas

I was able to post two of the recordings (made off my phone) on my blog. Here is a link to the blog. The recordings are like embedded YT vids, more than halfway down the page.

https://interrocknation.blogspot.com/2024/07/shortwave-mystery-roaring-jet-noises-in.html
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: tiNG on July 25, 2024, 0554 UTC
HI.

Sounds like STANAG4285 to my ears. If so then it would be coming from Australia (MHFCS Canberra via TX site Humpty Doo - -12.536056, 131.063250).

Hope this helps.
Title: Re: UNID Jet noise, 14356-14357 kHz, S4 (out of 5) & propagating, 0824 UTC
Post by: BoomboxDX on July 25, 2024, 2158 UTC
tiNG, thank you for your response!

Australia would indeed make sense, as propagation would favor regions across the Pacific to the West of me.