The purpose of the letter beacons is not yet known with certainty. Many theories have appeared in specialized publications, but none are based on documentary evidence. They have been postulated to be radio propagation beacons, channel markers, or beacons used in tracking satellites or for civil defense purposes. [12]

The Channel Marker feature allows you to send a tone across a particular talkgroup which will occur every 10 seconds until terminated. The marker indicates that the talkgroup is restricted to emergency traffic only.

2019年11月16日 · Marine CW channel markers/beacons. We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

2022年3月5日 · The purpose and the applications of letter beacons are not yet known with certainty. Many theories and speculations have appeared in specialized bublications, but none is based on documentary evidence. They have been postulated to be radio propagation beacons, channel markers, used in tracking satellites, or used for civil defense purposes.

2020年10月25日 · Marine CW channel markers/beacons. We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

2023年9月12日 · The channel markers are mostly attributed to Russian operators. This article presents an overview of the most commonly used radio signals in the high-frequency (HF) or shortwave spectrum.

2023年12月27日 · Morse Code is the simplest form of transmission found virtually all over the RF Radio Frequency bands for a variety of uses. The most common use of this is for Call-sign Beacons by both Amateur and Military operators.

They have been postulated to be radio propagation beacons, channel markers, or beacons used in tracking satellite or for civil defense purposes. Some stations of this family, in particular the “U” beacon, have been implicated in deliberate jamming .

2007年11月22日 · If somebody turns on their radio or switches to that particular channel, the "beeper" indicates that ONLY priority/emergency radio traffic is authorized. Just because there is a significant incident being worked on that channel, it doesn't mean that there will be a lot of radio traffic to indicate such an event.

2022年6月8日 · There's still SITOR channel markers from Greece and Turkey (slow CW ID's for SVO and TAH), NAVTEX on 518 and 490, and some rapidly disappearing DGPS stations in MF. As of Feb 2022 the USCG will no longer monitor (watch standing) the HF SSB frequencies, but will continue to monitor the HF-DSC.