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Crystal sets, POW radios, spy sets & radio related thread

endure

GCM
Have just been listening to CH19 on cb from an sdr in Cheshire


By God they seem special!


Try interrupting a net on 80 metres where the main subject of discussion is dentures and piles ;-)
 
Gen question - I'm presuming you have a ham licence - What would the reaction / response be if a non-ham licenced person bought one of those and attempted to converse with others on various channels?

Somewhere or another I'm licensed on aeronautical freqs but...I doubt I can just tune into Heathrow ground and give it "One Nine for a copy" :)
We have ACMA here in Aus (Australian Communications and Media Authority) who have vehicles with these awesome bits of kit on the roof that can track you down from your transmissions.

ACMA_van.jpg


Once they've got you, big fine and equipment confiscation.
 

endure

GCM
We have ACMA here in Aus (Australian Communications and Media Authority) who have vehicles with these awesome bits of kit on the roof that can track you down from your transmissions.

View attachment 503028

Once they've got you, big fine and equipment confiscation.


I hope they've got more than one to do a bit of triangulation otherwise I can't see that overtaking anyone transmitting mobile...
 
I hope they've got more than one to do a bit of triangulation otherwise I can't see that overtaking anyone transmitting mobile...
They've got mobile units as well, can't find a pic of them but I have seen them driving around. They've got these antennas on the roof that look like four J pole's welded together.
 

itchy300

Old-Salt
Reference DF, I take it that's a royal signals game (conventional war scenario) and how did/does that work WW2 to present day?

Its not something usually mentioned but I started taking an interest around the time of the recent Russia/Crimea....conflict?
 

endure

GCM
Bellini-Tosi in the merch. I never saw it used at all in 10 years but it was a statutory requirement so it had to be fitted.

lodestar3.jpg


bellini.jpg
 
HFDF ... Huff Duff ... was certainly successfully used to the expense of German U Boats in WW2 ... see ~19.00 to ~23.00 ...


... keep transmissions short or you may be located .
 

endure

GCM
I presume used to locate lifeboats and replaced by the SART/radar setup?

There was a chain of non directional radio beacons (similar to the aero beacons) around the world that transmitted on 285-315Khz that you could use for navigational purposes although I've never been on a ship that did.

The Lodestar pictured above could receive on 285 to 550Khz and also on 2182Khz which includes both the marine distress frequencies (500Khz CW and 2182Khz RT) so you could use the DF to get a bearing on a ship in distress. Fortunately I never had to do that either.
 
There was a chain of non directional radio beacons (similar to the aero beacons) around the world that transmitted on 285-315Khz that you could use for navigational purposes although I've never been on a ship that did.

The Lodestar pictured above could receive on 285 to 550Khz and also on 2182Khz which includes both the marine distress frequencies (500Khz CW and 2182Khz RT) so you could use the DF to get a bearing on a ship in distress. Fortunately I never had to do that either.
Recognised the Lodestar DF set. Some bridges could be like a navigation museum, with Decca, Loran and GPS. Never saw a sextant though they probably had one in a drawer somewhere. Chinese and Russian youth did foxhunting in forests or wherever with portable DF sets.

I know you know about this stuff but others may not, so I'll mention it here. A primitive method of finding a rough bearing was to slowly rotate a LW or MW radio to find the best signal or the best null, which could be more accurate than the peak. Specifically designed DF radios made this easier with a rotatable ferrite rod antenna on the top of the set.

1599737981176.png
1599738110084.png


More on DF radios and principles:
Radio Direction Finders
Radio direction finder - Wikipedia
 

itchy300

Old-Salt
There was a chain of non directional radio beacons (similar to the aero beacons) around the world that transmitted on 285-315Khz that you could use for navigational purposes although I've never been on a ship that did.

The Lodestar pictured above could receive on 285 to 550Khz and also on 2182Khz which includes both the marine distress frequencies (500Khz CW and 2182Khz RT) so you could use the DF to get a bearing on a ship in distress. Fortunately I never had to do that either.

That's a bit before my time but I heard rumours they were considering building a modern version of this as a contingency to GPS navigation. I'm not sure if anything has/will come of it though.
 

endure

GCM
That's a bit before my time but I heard rumours they were considering building a modern version of this as a contingency to GPS navigation. I'm not sure if anything has/will come of it though.


I never sailed with GPS (I'm very old) but did sail with its predecessor (Transit) on a few ships. There was Loran which I never sailed with either but all the ships I sailed on had Decca Navigator which worked in a similar fashion.

It was short range but installations were quite widespread around the world.
 
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endure

GCM
Recognised the Lodestar DF set. Some bridges could be like a navigation museum, with Decca, Loran and GPS. Never saw a sextant though they probably had one in a drawer somewhere. Chinese and Russian youth did foxhunting in forests or wherever with portable DF sets.


All British merchant deck cadets are taught to use a sextant to this day although, as you say, once they get to sea they find it in the back of a cupboard on the bridge unless the Mate is keen and makes them take sights.
 

itchy300

Old-Salt
I never sailed with GPS (I'm very old) but did sail with its predecessor (Transit) on a few ships. There was Loran which I never sailed with either but all the ships I sailed on had Decca Navigator which worked in a similar fashion.

It was short range but installations were quite widespread around the world.

I vaguely remember being taught Loran but it was nothing more than making us aware that the system used to exist. Navigation is either GPS or sextant nothing in between which seems crazy
 

endure

GCM
I vaguely remember being taught Loran but it was nothing more than making us aware that the system used to exist. Navigation is either GPS or sextant nothing in between which seems crazy


There was nothing more satisfying than watching a gaggle of deck cadets being shouted at by the Mate because they'd buggered their noon sights up :clap:
 

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