Are radio direction finders completely obsolete?

[CaptTom]

SAR responders like the Coast Guard still use RDF to find where someone is transmitting a distress call from. There are MOB solutions which use it. Recreational fishermen used to use it to find where the other boats were catching fish, but I'm not sure if that's still a thing.

So it's not just for navigation. But not something you really see any more in the recreational world.

[Chotu]

With boats? They are pretty much out of use.

With airplanes however? People still use them.

ILS/GBAS Approach beacons. They guide the plane down using radio direction finders, I believe

[Jammer]

Originally Posted by Sailor Sailor

Have radio direction finders become completely obsolete?

They are obsolete for marine navigation except as a historically interesting technique.


They are still in use in aviation, to a limited degree, and will likely remain so. They offer a cost effective mitigation for jamming of GPS signals, which is more a problem for aviation users than maritime (and other surface) users because GPS signals can be jammed from a greater distance away at altitude.


As noted upthread, DF is in widespread and growing use for SAR and surveillance use where the objective is to determine the location of a transmitter rather than to determine the location of a receiver. Modern systems generally use the signal arrival time difference among antennas (usually four spaced 4-8 feet apart) rather than a loop antenna. The USCG's Rescue 21 system has DF capabilities that are used both to localize vessels in distress and as a means to determine whether distress calls are genuine.

Are there still stations transmitting signals?

I do not believe that any marine radiobeacons remain in use, realizing that the world is a big place and there's probably a handful of them somewhere.


Some (many) airports still operate NDBs, and this is likely to continue until eLORAN or some other wide-area terrestrial navigation system is in commercial service. NDBs are inexpensive to operate.



There has not (to my surprise) been any significant reduction in the numbers of broadcast radio and TV stations (see for example https://www.statista.com/statistics/...ons-in-the-us/), nor AM MF broadcast stations in particular, and so these remain useful for radionavigation.

[thomm225]

A few Beacons are still transmitting and used in the Golden Globe Race 2022 plus other transmitters.

https://mechtraveller.com/2022/09/go...ng-old-school/

From the link above.

GGR skipper Guy Waites told me that there were only two beacons covering the route of their pre-GGR race from Gijon in northern Spain across the Bay of Biscay to Les Sables d’Olonne. He managed to find a signal from one of them but not the other. However, GGR sailors don’t give up that easily. He tuned to BBC Radio 4 on 198 longwave, found the null spot in the signal and was able to use that as a second bearing because he knew the transmitter is in Droitwich!

[goboatingnow]

Originally Posted by CaptTom

SAR responders like the Coast Guard still use RDF to find where someone is transmitting a distress call from. There are MOB solutions which use it. Recreational fishermen used to use it to find where the other boats were catching fish, but I'm not sure if that's still a thing.

So it's not just for navigation. But not something you really see any more in the recreational world.

Virtually all recent EPIRB and PLB now send GPS co-coords , and AIS and DSC mob and ship distress Also do , less and less rescue craft carry RDF. RNLi Ribs dont.

Some of the bigger rnli lifeboats carry radio directional finders , but this is not beacon tracking , it can locate vhf radio for example

For navigation purposes RDF marine is obsolete virtually completely. Perusing my Admiralty 2021 radio signals book shows only a handful,remain . Certainly not enough for coastal navigation anywhere round the Uk or Europe for that matter.

We have 4 Gnss systems and the firmament remains as it always was, no need for RDF at all.

[goboatingnow]

Originally Posted by thomm225

The question was are Radio Direction Finders completely obsolete? Answer: No, they are not completely obsolete.

They are still available and there are beacons along the GGR Route.

Obsolete usually means not available.

RDF's are available and there are transmitters still sending out the required signal

I have worked in the Electronics/Computer Field since the 1970's. I am very familiar with obsolete equipment.

Computer Technology changes so fast it will make your head spin. So I am used to finding replacement parts but when they are obsolete we have to upgrade.

We just recently replaced our main frame, 386, and 486 computers. November 2019.

It’s obsolete and most maritime beacons are closed, just because something is obsolete doesn’t mean a few relics remain. The steam locomotive is obsolete but several pound up and down UK main railways every month.

[goboatingnow]

Originally Posted by thomm225

A few Beacons are still transmitting and used in the Golden Globe Race 2022 plus other transmitters.

https://mechtraveller.com/2022/09/go...ng-old-school/

From the link above.

GGR skipper Guy Waites told me that there were only two beacons covering the route of their pre-GGR race from Gijon in northern Spain across the Bay of Biscay to Les Sables d’Olonne. He managed to find a signal from one of them but not the other. However, GGR sailors don’t give up that easily. He tuned to BBC Radio 4 on 198 longwave, found the null spot in the signal and was able to use that as a second bearing because he knew the transmitter is in Droitwich!

Good thing as bbc are committed to closing all long wave as the transmitters fail

[thomm225]

Originally Posted by goboatingnow

It’s obsolete and most maritime beacons are closed, just because something is obsolete doesn’t mean a few relics remain. The steam locomotive is obsolete but several pound up and down UK main railways every month.

What's your problem?

RDF's are still being used which means they are not obsolete.

An example of obsolete would be the computers I used to load with Octal or BCD.

There was no GUI back then for folks like you to use.

You won't find those computers being used in business etc. today.

[capt jgw]

Originally Posted by El Pinguino

The problem with AM transmitters is that many are not located where you think they are located.

Right, the actual transmitters are often many miles away from the studios or the cities they're supposedly broadcasting from. You have to know where the towers are, the ones close to the water are on the nautical charts but inland ones are not. And that's the old paper charts, I don't know if they're on digital. They are on aviation charts, but that's more to prevent planes hitting them rather than RDF use.

[goboatingnow]

Originally Posted by thomm225

What's your problem?

RDF's are still being used which means they are not obsolete.

An example of obsolete would be the computers I used to load with Octal or BCD.

There was no GUI back then for folks like you to use.

You won't find those computers being used in business etc. today.

As I said re steam locomotives , obsolete doesn’t mean not used. It means not commonly used as was the case when they were used extensively

I put two working oscilloscopes in the bin , they worked but are obsolete

Marine RDF is obsolete , few marine beacons exist , no small boat equipment is being produced and old ones are impossible to repair.

It’s the very definition of obsolete.

Again niche occasional use doesn’t affect obsolescence status. It cannot be used for its intended purpose , ie marine navigation , hence it’s obsolete

[thomm225]

Originally Posted by goboatingnow

As I said re steam locomotives , obsolete doesn’t mean not used. It means not commonly used as was the case when they were used extensively

I put two working oscilloscopes in the bin , they worked but are obsolete

Marine RDF is obsolete , few marine beacons exist , no small boat equipment is being produced and old ones are impossible to repair.

It’s the very definition of obsolete.

Again niche occasional use doesn’t affect obsolescence status. It cannot be used for its intended purpose , ie marine navigation , hence it’s obsolete

Sorry RDF's are not obsolete as they are being used to help sailors navigate their way around the world at this moment which to me seems pretty important so they won't like destroy their boats.

Steam Locomotives is a sad example but I guess that is all you can come up with

[capt jgw]

Originally Posted by CaptTom

SAR responders like the Coast Guard still use RDF to find where someone is transmitting a distress call from. There are MOB solutions which use it. Recreational fishermen used to use it to find where the other boats were catching fish, but I'm not sure if that's still a thing.

So it's not just for navigation. But not something you really see any more in the recreational world.

But an old navigation RDF won't do that, it's on the wrong frequency band.

[goboatingnow]

Originally Posted by thomm225

Sorry RDF's are not obsolete as they are being used to help sailors navigate their way around the world at this moment which to me seems pretty important so they won't like destroy their boats.

Steam Locomotives is a sad example but I guess that is all you can come up with

Using a peculiar race that is in my opinion bizzare and virtually the definition of niche , is nonsense

It’s all you can come up with. That race, with a handful of users , unlike the 100,000 passengers pulled by obsolete steam locos.

Maritime operators have shut down beacons , virtually no one makes the gear and you can’t navigate major coasts with RDF.

It’s obsolete by very definition , even if some weird 1920s nostalgia race supposedly thinks it’s great ( along side modern AIS trackers etc )

[thomm225]

Originally Posted by goboatingnow

Using a peculiar race that is in my opinion bizzare and virtually the definition of niche , is nonsense

It’s all you can come up with. That race, with a handful of users , unlike the 100,000 passengers pulled by obsolete steam locos.

Maritime operators have shut down beacons , virtually no one makes the gear and you can’t navigate major coasts with RDF.

It’s obsolete by very definition , even if some weird 1920s nostalgia race supposedly thinks it’s great ( along side modern AIS trackers etc )

Okay you are like a broken record so there is no need to argue as it will not change your mind.

Now you can go respond to most all the other recent posts......with pretty much your same daily speech

[goboatingnow]

Originally Posted by thomm225

Okay you are like a broken record so there is no need to argue as it will not change your mind.

Now you can go respond to most all the other recent posts......with pretty much your same daily speech

Sorry your the one persisting

And I’ll post as much as I like to counter the abject nonsense here

Open your recent copy of “ Admiralty Guide to radio signals “ look up RDF beacon info

When you actually know what your talking about then tell me it’s not obsolete

Oh by the way could you link new small boat RDF equip manufactures , yep thought so.

It’s obsolete, a few weird racers will not use it , actually , so what.

It’s not a question of changing my mind You are just wrong that’s all.