Radio Location

Tseralo

Member
Are there any modern resources out there for building radio location equipment and how it works? I'm struggling to find anything that's not a webpage from the early 90s with components that haven't been in production since then.
 
It seems all the people who%u2019ve built radiolocation gear and published in CREGJ or Speleonics long ago are even older than me!

The principles of how to put whatever the electronic gear might be into use for actually surveying a cave is explained in Chapter 9 of Bryan Ellis %u201CSurveying Caves%u201D book (BCRA 1976) and many articles in CREGJ over the years and at CREG field meetings.

As to circuits, there is the 874Hz circuit I published with Bob Mackin in Caves & Caving No.52 Summer 1991.  There is a more sophisticated design by Brian Pease in CREGJ but all the details of this 3946Hz system and PCBs and hard-to-find parts info is all up to date and at https://radiolocation.weebly.com/ and CREG did have a demo working pair until a few years ago when they gave them away for some reason to Wessex CC (ask Les Williams).

Obviously last-century transmitter designs used such as 4000-series CMOS chips to generate the transmitted tone while newer designs would use a microcontroller which could also turn the device on and off at predetermined times so, for example, you could place an underground transmitter one weekend and do the surface side of the job on the following weekend all by yourself.

Perhaps the most difficult part is designing and building a good receiver circuit and the construction of loop antennae which need to be carefully wound and symmetrical to achieve an accurate result.  Winding multicore cable on to some rough and ready former will not give an accurate result like single strand wire bank-wound on to a rigid former.  Of course the transmitter antenna has to be carried into a cave which can presents problems - it might need to be collapsible and rebuilt at its position of use and I've found ribbon cable to be convenient if it has to be packed in a Daren Drum to transport.  Again, CREGJ at https://bcra.org.uk/pub/cregj/ is your friend in times of trouble with all kinds of bizarre antenna ideas - even one looking like an umbrella with spokes...

I have not tried this, but I think it is worth a try.  A domestic Long Wave radio saves you the bother of designing a good receiver and its ferrite rod antenna internally is inherently directional.  So tuning it to some unused part of that radio spectrum and building an AM transmitter with tuned loop antenna to match it might be a development short cut, at least for measuring shallow cave depths.

Anything involving DIY inductors is a bit of a black art needing experimentation, but I hope this helps you get started.



 

Leclused

Active member
Leclused said:
Hi,

We?ve used an Arcana tool last year with succes to locate the position for a new entrance in our project in France.

In the following toreador you find some info
https://ukcaving.com/board/index.php?topic=28273.msg353404#msg353404

The tool we used was build by a caver friend. If you
want I can get you in touch with him

In the 2021 report there is photo of the tool.

I forgot the link to the report

https://www.dropbox.com/s/bo9pb3ulxvwa00g/5.%20De%20vijfde%20reeks%20expedities%20-%20kopie.pdf?dl=0

The Arcane tool can be seen on page 29
 

SamT

Moderator
Ron Hammond of Eldon/Buxton had a kit that we used at Bagshawe, but I've no idea if he still has it.  Might be worth asking the likes of Bob Dearman if Ron is still around.  I've got it in the back of my mind that maybe his son was taking up the radio location mantle.

Nick Williams might be worth a shout too for anything electronics related.
 

Leclused

Active member
Leclused said:
Leclused said:
Hi,

We?ve used an Arcana tool last year with succes to locate the position for a new entrance in our project in France.

In the following toreador you find some info
https://ukcaving.com/board/index.php?topic=28273.msg353404#msg353404

The tool we used was build by a caver friend. If you
want I can get you in touch with him

In the 2021 report there is photo of the tool.

I forgot the link to the report

https://www.dropbox.com/s/bo9pb3ulxvwa00g/5.%20De%20vijfde%20reeks%20expedities%20-%20kopie.pdf?dl=0

The Arcane tool can be seen on page 29


Just found out that there was an update of the Arcana tool (perhaps you can try to contact them)

http://speleo-club-souillac.e-monsite.com/pages/documents-techniques-progession-topographie/arcana.html

 
Closer to home, Shropshire Caving and Mining Club have used radio location and may be able to help.
https://www.shropshirecmc.org.uk/locator.html

Try contacting scmc.secretary. (address on the links page)
 

Leclused

Active member
Wayland Smith said:
Closer to home, Shropshire Caving and Mining Club have used radio location and may be able to help.
https://www.shropshirecmc.org.uk/locator.html

Try contacting scmc.secretary. (address on the links page)

Looks like the arcana 😀 and probably works in the same way
 
Leclused said:
Wayland Smith said:
Closer to home, Shropshire Caving and Mining Club have used radio location and may be able to help.
https://www.shropshirecmc.org.uk/locator.html

Try contacting scmc.secretary. (address on the links page)

Looks like the arcana 😀 and probably works in the same way

We used Ken Smith's "pinger" at Wookey Hole (after Brian Prewer's kit broke) to re-recheck previous radioloaction points and track the progress of the tunnel from 9 to intercept 20.  See https://cdg.caves.org.au/CDG-Articles/SA/SMITH-ThePingerSA2008.pdf - although designed to be used underwater, we simply suspended the transmitter vertically in dry cave passage from a tripod made from plastic pipes.
 
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