ICOMJAPAN: Shortwave Utility Stations what a SWL can hear on SW?

mercredi 5 juillet 2023

Shortwave Utility Stations what a SWL can hear on SW?

Everydody know radios, amateur radio, citizen band, but between 3 and 30 MHz there are a lot of strange sounds, only few are men or women talking in SSB.

The main uses of the high frequency spectrum are:

Military and governmental communication systems
Aviation air-to-ground communications
Shortwave international and regional broadcasting
Maritime sea-to-shore and ship-to-ship services
Over-the-horizon radar systems
Global Maritime Distress and Safety System (GMDSS) communication
Coastal ocean dynamics applications radar

but they are also number stations, clandestines radios, pirates radios and many more.

Confidentiality of communications (by law, it is prohibited to disclose the content of conversations overheard except in broadcasting, this being valid for most users of radio systems)

With a web sdr like this one in netherlands http://websdr.ewi.utwente.nl:8901/ you can have many informations.

This web SDR give informations for SWL to know who is transmting of listed frequencies.

On 11253 a lady in LSB give infos about Weather forecast This is the Royal Air Force Weather Service. "Volmet" has its root in French and appears officially as "Meteorological Information for Aircraft in Flight" Catchy, but I still don't see the connection.

High frequencies ( SW ) have long been used for many purposes: military, maritime, air, and diplomatic. Since the 1980s, with the development of satellite and terrestrial relay links, HF waves have gradually been abandoned by official services and broadcasting. However, they remain essential for certain maritime and air services, in particular to guarantee the safety of ocean links, for fixed or mobile links in areas without infrastructure or in emergency situations, in the event of a natural disaster or even for military traffic. The signals can be unencrypted analogue, encoded or digital with or without conditional access (encryption).

When i was in the French army ( artillery )

I learn CW during 6 months

The frequency bands are allocated by the ITU. During the 2000s, broadcasting represented 13% of the spectrum, maritime traffic 20%, air traffic 10% and the amateur bands 12%, the rest of the spectrum being used by fixed or mobile services.

https://fr.wikipedia.org/wiki/Haute_fr%C3%A9quence

https://en.wikipedia.org/wiki/High_frequency#

The Morse code CW is still in use but in the past during the WAR or COLD WAR this mode was very used. On internet you can find a lot of web sites who explain all there strange signals

https://www.ciphermachinesandcryptology.com/en/coldwarsignals.htm

https://chnm.gmu.edu/1989/items/show/304.html

https://www.ripleys.com/weird-news/number-stations/

I will give you some links if you are interested by these stranges sounds and signals on ShortWave

https://www.hfunderground.com/wiki/Shortwave_Utility_Stations

https://wiki.radioreference.com/index.php/Main_Page

http://www.udxf.nl/

Maritime stations, both coastal stations and ships
Aeronautical stations, both ground stations and aircraft (voice, HFDL, Selcalls,
Volmet, etc.)
Military stations
Beacons (NDB, Driftnet beacons, Propagation beacons, Pirate beacons, Hi
Frequency beacons, etc.)
Fax stations
Numbers stations, diplomatic stations, clandestines and oddities
Radars (Over-the-Horizon-Radar, Ocean Wave Radar, CODAR, etc.)
Ionosondes, Chirpsounders
ALE-systems, Selcall-systems, Tone calls
Experimental stations
Standard frequency and time stations
Utility radio related HAM events, such as the International Lighthouse Weekend,
Night of Nights, etc.