Many thanks to SWLing Post contributor, Pete Jernakoff, who writes:
Last Saturday evening, I was cruising through the SW bands and came across music and talk on 2640 kHz, a rather odd (I would think) frequency on which to find such a broadcast format.
The music was of the soft pop variety (for example “Vou de Taxi” by Angelica; “A Time For Us – Love Theme from Romeo and Juliet” by Jack Jones; “A Lua E Eu” by Cassiano), and it sounded to my ears that the on-air talent (male) was speaking (between songs) either in Portuguese or in a Brazilian dialect of said language.
I have attached an audio clip of this broadcast [see below] which begins at 0158 UTC (on 26-March-2023). The recording is a little over 13-minutes long and ends when the signal abruptly leaves the air.
Note that there is a seeming mention in the recording of the words ‘Brazil’ and ‘Brasilia’ at the 4:40 and 5:03 time points, respectively. I have no clue where this signal originated, and I’m hoping that you or one of your many readers might be able to help ID this one. As far as I’m aware, there is no station that broadcasts on this frequency at least with this kind of programming. The signal seemed too strong to be a harmonic of a station broadcasting on, say, 1320 kHz. Perhaps a pirate? A mystery to me…
Thanks for sharing this recording, Pete!
If you can help Pete ID this mystery recording, please comment!
Many thanks to SWLing Post contributor, Paul Walker, who writes:
I had a strong s9+20 signal on 9595kHz Mon Jan 9th, 2023 here in Alaska in the 1900UTC hour with nothing but a repeating loop of the same island-y like music. The track was about 3-5 minutes long and there was no station announcements of any kind between the one repeating track. It was gone by 2000UTC. No one is listed on eibi, short-wave.info, shortwaveschedule.com or HFCC Raw data for this frequency at this time.
Who is it? It sounded too clear and good to be China, but I suppose that’s possible.
I received the following message from my buddy Rob (NC0B) who is trying to identify a couple of signals on the 20 meter band. Rob kindly gave me permission to post his email here on the SWLing Post with the idea that someone may be able to help him solve this:
The following is a description of two odd digital signals observed on 20 meters with transmission modes I do not understand. They may not amateur transmissions, but I have no way to decode them. They stick out like a sore thumb on 20m in the Extra portion of the phone band. The time of day on August 20th was between 11:50 AM and 12:00 PM MDT.
Two weeks ago I was in QSO on 14,170 kHz and occasionally there was the same 10 kHz wide digital signal but centered on 14,171 kHz. It sounded like the old Russian jammers buzz saw modulation. Those signals from decades ago were much wider, and or course we didn’t have high resolution spectrum scopes back then. Today the same transmissions occurred several times, and more than once a minute for about 5 seconds each. In total the transmissions may have occurred on and off for about 10 minutes.
Then after a few 10 kHz transmissions a different signal came on the air a few times with what looked like a digital modulated carrier plus digital sidebands on each side of the middle signal.
Look at the attached JPG file and I’ll try to make sense out of it:
The waterfall image lasts about 50 seconds on the Icom IC-7610 set on slow. There are two different signals to differentiate in this image. The signal I observed two weeks ago and today is 10 kHz wide and today spans from 14,178 to 14,188. It shows up in green on the band scope, and just under it in blue on the water fall for about 3 seconds of the approximate 5 second transmission. You can also see at the bottom of the waterfall the previous transmission that has about 4 seconds worth saved on the waterfall running off the bottom. The horizontal span of the scope was set to 5 kHz per division.
Once the 10 kHz wide signal started, I went to Dual Watch so I could listen for KL7QOW on 14,170 kHz for a sked, and hear the buzzing signal on 14,183 kHz in SSB mode. That frequency placed the carrier position of the SSB 2.8 kHz bandwidth in the center of the 10 kHz wide signal.
Soon after I started observing the relatively flat spectrum of the 10 kHz signal, a new digital signal appeared about 3 kHz lower in frequency. At first it had a much stronger center modulated carrier about 2 kHz wide and then two symmetrical digital signals on each side within about a 6 kHz total bandwidth. I wasn’t able to capture the best picture of the 2nd signal as it appeared to be tuning up. The amplitude difference between the central signal and the separate sidebands initially was about 15 dB. Vertical divisions are 10 dB.
On the waterfall you can see the second type of signal is centered on about 14,180 kHz. The modulation depth of the outer pairs of signals were not constant, possibly due to selective facing. QSB was quite significant at this time at least to Alaska. You can see there was a short break of a few seconds in the 6 kHz wide signal. Every time I have seen the 10 kHz wide signal its amplitude across the transmission bandwidth has been fairly constant, always of short duration, and repeating several times within 10 minutes before terminating.
Does anyone have any idea what either of these transmissions are? I have heard of email digipeaters, but I would not think their bandwidth would be this wide.
SWLing Post community: Please comment if you can help Rob ID these signals!
Many thanks to SWLing Post contributor, Patricia, who writes with the following inquiry:
I wonder if anyone has heard and identified the station or signal I heard on 7075 kHz at 0745 October 30, 2021 on my C. Crane Skywave, and I live in southern California. I would like to know where this signal originates, sounding something like a numbers station, no voice, but a whooshing sound. I have heard it may be a ham frequency or a signal from space. Any ideas?
Thank you for your question, Patricia.
I believe what you’re hearing is the ham radio digital mode called FT8.
FT8 is a weak signal digital mode that is extremely popular in the ham radio world these days. The mode isn’t designed around relaying lengthy messages, rather it’s designed for short, very formulaic exchanges.
Each message of up to 13 characters takes 13 seconds to send. For FT8 operators to be successful, they try to keep very accurate timing on their computing device controlling the transceiver. When the whole group is coordinated well, you’ll hear groups of signal tones singing all at once in 13 second intervals with a couple seconds of space between messages.
Here’s what FT8 sounds like in SSB mode:
It’s possible it sounded quite different, however, if you were listening in AM mode.
If this doesn’t sound like what you heard, perhaps you can check the comments for any other possibilities, but my guess is it’s FT8 as it’s a pretty strong chorus of tones!
Many thanks to SWLing Post contributor, Carlos Latuff, who shares the following:
I bought a small analog radio and I’ve been listening with it.
On September 4, around 17h48 UTC, I heard a strange signal on the band of 13 kHz, since it’s not a digital dial, I don’t know precisely the frequency but maybe if your readers may listen to the signal they may tell what it is about.
It almost sounds like the preamble to an SSTV message, but I’m not sure about that noise that’s in between. Readers, if you can help Carlos ID this signal, please comment!
Many thanks to SWLing Post contributor, Carlos Latuff, who shares the following video of sounds he heard on HF. Carlos adds, “Are we in the Twilight Zone or Lost in Space? They sound like effects from a 60’s/70’s sci-fi movie!”