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:
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:
Thank you, Tom.
Post readers: If you can shed some light on these transmissions, please comment!
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.
Many thanks to SWLing Post contributor, Jim Meirose, who recently logged a mystery signal and is asking for our help to identify it. Jim notes that it sounds much like a time signal and can be found on 4,806 kHz.
Jim lives in the north east US and is receiving the station each morning between about 5:00 – 8:00 EDT (9:00 – 12:00 UTC). He shares the following video:
Based on Jim’s description, I thought this might even be a local noise, but after hearing the audio and since the signal is following morning propagation, I’m guessing the source could be in Europe or possibly regions further east–?
This is the musical marker for CPRM Lisboa, a radiotelephone terminal that provided overseas telephone and telegraph communications in the days prior to satellites.
I remembered the non-broadcast HF frequencies being loaded to bursting with many of these radio services. When not scrambled for privacy, one could hear a telephone call in progress. Instead of a musical IS such as this one, most were loop tape voice ID’s in several languages (almost always including English). So naturally these musical loops made it quite difficult to know what exactly one was hearing, to say the least!
To verify check out the following embedded audio file made by Willi Passmann (via the excellent UtilityRadio.com website):
Once again, thanks to Dean Bianco for solving yet another mystery! Obviously, Dean is a Black Belt SWL and DXer!
FYI: I’ve received a number of emails from readers who really enjoy these mystery signals. Since we all seem to have more time at home these days, I’ll plan to keep them coming!