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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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18th Jun 2019, 10:55 pm | #1 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
Posts: 373
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Non broadcast uses for low frequencies
I have been looking at Ofcom's UK frequency table which lists the band between MW and LW (526.5 KHz to 283.5 KHz) and below LW (148.5 KHz right down to 8.3KHz) as being allocated to maritime mobile and aeronautical radionavigation use. Below 8.3KHz is not allocated. In this age of satellites, GPS etc are these low frequencies really any use for communication and navigation?
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Regards Martin |
18th Jun 2019, 11:18 pm | #2 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,085
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Re: Non broadcast uses for low frequencies
Below the LW Broadcast band, see VLF Stations List
Between LW and MW there are still a few NDBs left, but the move now is to DGPS, see The DGPS List
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18th Jun 2019, 11:21 pm | #3 |
Pentode
Join Date: Oct 2018
Location: Coventry, West Midlands, UK.
Posts: 220
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Re: Non broadcast uses for low frequencies
NDB's (non directional beacons) use the frequency range 190 kHz to 535 kHz and are still very much in use in aviation.
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18th Jun 2019, 11:22 pm | #4 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,085
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Re: Non broadcast uses for low frequencies
See also the thread Ultra VLF signals?
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- Julian It's good here |
18th Jun 2019, 11:48 pm | #5 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,786
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Re: Non broadcast uses for low frequencies
I believe VLF is still used for military submarines:
https://en.wikipedia.org/wiki/Commun...ith_submarines https://en.wikipedia.org/wiki/Anthorn_Radio_Station |
18th Jun 2019, 11:54 pm | #6 |
Pentode
Join Date: Oct 2018
Location: Coventry, West Midlands, UK.
Posts: 220
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Re: Non broadcast uses for low frequencies
Over 100 NDB's currently in use in the UK
http://www.infotechcomms.net/downloads/ndbs.pdf |
19th Jun 2019, 12:19 am | #7 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
Posts: 373
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Re: Non broadcast uses for low frequencies
Thank you for your replies, this is a fascinating subject. Do land based navigation systems have any advantage over satellite GPS? On a separate note, 135.7KHz to 137.8KHz is also allocated for amateur use with a maximum ERP of 1W. What would amateurs use this band for?
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Regards Martin Last edited by martin.m; 19th Jun 2019 at 12:22 am. Reason: more information |
19th Jun 2019, 8:52 am | #9 |
Pentode
Join Date: Oct 2018
Location: Coventry, West Midlands, UK.
Posts: 220
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Re: Non broadcast uses for low frequencies
The Flight Management System on a typical airliner uses several sources of position information including ground based nav aids, an inertial reference system (gyros and accelerometers) and GPS. This provides redundancy and cross checking, using GPS alone would not be a viable option as it would not provide the necessary back-ups (in fact ground based nav aids are still very much considered the primary navigation source with GPS used for backup and cross checking). Also as the GPS system is owned and operated by the US government it could in theory be switched off or degraded at any time, although this is unlikely it does mean that it would be unsuitable as the primary navigation source for commercial aircraft.
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