Tag Archives: Mystery Signals

Can you ID this ham radio digital signal for Rob?

Many thanks to SWLing Post contributor, Rob, who writes:

I have a question about the digital signals I received today during what must have been an E skip opening to the southwest.

Can you identify by the bandwidth the wide signal in one screen capture vs. the normal FT8 signals which were decoding today quite well using the 7610?

Typical 6 meter band FT8 signals

Wide digital signal on 6 meters.

The wide signal didn’t decode in FT8 mode, but I have no idea what mode was being transmitted. Any idea?

Great question, Rob. I’m posting this because I’m no expert on timed digital mode signals. I recognize FT8, and assume this could be FT4, JT65 or similar, but the timing is identical to FT8. I’m sure someone in the Post community will solve this signal mystery in very short order!

Readers: Can you help Rob ID this wide, timed digital mode signal? If so, please comment!

Carlos seeks clarity about another CW station

17 Replies

Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

Today (June 5, 2021) I heard another mysterious CW transmission here in Rio Grande do Sul coast, this time on 8779 kHz, 18h31 UTC.

I did some research and this frequency is related to Rome Radio (which is no longer transmitting in CW) and a marine channel (ITU821) related to Cape Town Radio but I’m not sure:
https://capespectrum.wordpress.com/hf-marine/

I’m sure your readers will solve this puzzle as well.

Thanks for sharing, Carlos!

Post readers: Can you help Carlos ID this station? Please comment!

Can you help Carlos identify this CW station?

6 Replies

Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

Hey Tom,

Check out this recording.

I heard it today on 16976 kHz USB, at 13h08 UTC, here in Tramandai coast, Rio Grande do Sul, Brazil.

Maybe your readers may have an idea what is this CW about?

Thank you for sharing this, Carlos!

Post readers: If you can ID this station, please comment!

Can you help Tom ID this CW transmission on 7039.60 kHz?

6 Replies

Many thanks to SWLing Post contributor, Tom (DF5JL), who writes:

At the end of last year it appeared for the first time: a telemetry transmitter in CW on 7039.60 kHz. It always transmits at the 2nd, 22nd and 42nd minute of every hour. Every day.
Reception reports are available from Germany, the Netherlands, France and Greece. Three numbers and a V are transmitted ten times in succession, as follows:

0522 UTC: 121V
0542 UTC: 121V
0622 UTC: 122V
0722 UTC: 123V
0822 UTC: 125V
0842 UTC: 127V
0902 UTC: 128V
0922 UTC: 129V

During the day the values increase, in the afternoon they decrease. It is assumed that voltage values are transmitted here, i.e. “121V” would correspond to 12.1 volts. You can listen to a recording here:

Any idea?

73 Tom

Thank you, Tom.

Post readers: If you can shed some light on these transmissions, please comment!

Can you help Bruce identify this shortwave noise?

14 Replies

Many thanks to SWLing Post contributor, Bruce (VE6XTC), who is trying to identify noises he’s hearing on the HF bands. Perhaps readers can help.

By request, Bruce has provided me with two recordings via his Kenwood TS-440S:

Recording 1: 7,335 kHz at 0500 UTC on September 13, 2020

Recording 2: 7,405 at 0500 UT on September 13, 2020

Post readers: If you can help Bruce by identifying these HF noises, please comment!

Carlos seeks help identifying a signal

7 Replies

Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

Hope this message will find you well.

I just monitored in Porto Alegre, Brazil, this signal on 9460 kHz. Searching on Internet I found that it’s the same frequency where the Russian MR-102 Baklan radar is operating. But it could be a weather fax. Do you have any clue?

Please, check attachment for the audio clip. Thank you in advance.

Thank you for sharing this, Carols. To my ear it does sound like some sort of slow-scan digital mode like weather fax, but I’ll leave it up to the SWLing Post community to help identify.

Post readers: please comment if you can ID this signal for Carlos.

UPDATE: Nils Schiffhauer found the answer. The signal is a weather fax transmission most liekly from Wellington, NZ.

Can you help Carlos identify this 1982 polytone broadcast?

9 Replies

Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

I have a tape with a recording I made in 1982 while listening to shortwave.

I’m not really sure if I caught some kind of polytone numbers station. Could you or your readers be able to identify it?