Cavechat.org

I am nearly finished with a new radio locator.
The receiver has been wired since the pictures were taken.
the receive loop is nearly finished(no pics)


Receiver & boards:


Transmitter & 24" loop:




Transmitter & 18' loop (it still needs a backing of some sort)

Nice work! 3.5 kHz?

It is now complete and 100% functional...
Thanks to Brian Pease for calibration.

What is the purpose of this?

YuccaPatrol wrote:What is the purpose of this?

I would guess... (wait for it)... radio location. Or in other words, the relationship between a given point inside a cave and the surface (or another part of the cave).

Mark - I'd be interested to know how well this is working out for you. Personally I'm holding out for a more compact version with reliable 2-way voice. Something a little more efficient than the old Drummond design, perhaps.

NZcaver wrote:Mark - I'd be interested to know how well this is working out for you. Personally I'm holding out for a more compact version with reliable 2-way voice. Something a little more efficient than the old Drummond design, perhaps.

The 2 way voice is WAY above my ability to produce, although I have schematics and parts list for it
as for the reliability of such, it is not quite there yet, or miners would have them.

I have considered smaller loops but they do not have the range and require transmitter modifications.
I also recently acquired a newly designed transmitter board, class E - higher efficiency and the loop is easier to design and make.

PS. I have all the electronics(including the PC boards) to build another complete system.

I finally tested the gear in the field:
Day one...did one location
it did not go so well
I had trouble locating the exact center and never actually found it but I was within a couple of feet.

Day Two...did 2 locations
it went fabulously
Located both spots

My gear should be able to locate spots >600 feet with out any problems. I do require at least one helper on the surface and if they can survey (it is very hard to stay at the exact elevation on a hill), I can calculate depth by multiple methods.

Ohhhkay so this could be conceivably used by Cave SAR groups to help a mobile drill to find the precise spot to dig in case the usual extraction method is too cumbersome or ok...lets just say it... impossible?

That is of course provided one can get a drill to the cave location.

Ralph E. Powers wrote:Ohhhkay so this could be conceivably used by Cave SAR groups to help a mobile drill to find the precise spot to dig in case the usual extraction method is too cumbersome or ok...lets just say it... impossible?

That is of course provided one can get a drill to the cave location.

As long as we can get the transmit loop to a target area too.

Ralph,

In a NSS News coming sometime soon, you might see an article where a home-built radio was used to locate the surface location of a remote dome and thus locate a new entrance to a formerly remote and rarely visited portion of cave. While a very accurate survey could also accomplish the same thing...many aren't accurate enough in long complex systems, especially those done in the 60's. If you don't have a survey to begin with then a radio becomes VERY helpful. They are also excellent for setting control points. You GPS a few surface radio locations and see how your survey overlay and the real world match

The AC magnetic field generated by this Beacon is safe for people but will quickly erase
the magnetic stripes on credit cards and phone cards, floppy disks, audio and video tapes.
It could damage computer hard drives, digital cameras and all storage media. Keep all
electronic equipment at least 10 feet (3 meters) away from the working loop. Also keep
the Receive loop at least 10 feet away to prevent Receiver damage from high voltage.


Transmit Loop ready to work - but not transmitting
Note: large loop is conneced & small loop shown is an alternate.
Only one is required. The larger loop is more powerful.


Packaged up & ready to cave


Recieve loop set up and working


close-up of working reciever


close-up of reciever

This is really cool!

Good work!

question...? is it work to get drililing point, in case that become easier for utilization underground water resources?.... because we need this tools, Please PM for more information and cooperation

(sori my english veri bad)
tanks...brooo

Lurah,

you can do a web search for "cave radio" and get lots of info. Someone with basic electronics and soldering knowledge can generally build one but it usually takes someone more knowledgeable to fine tune it.

Lurah_GB wrote:question...? is it work to get drililing point, in case that become easier for utilization underground water resources?

I don't think this was the primary purpose behind Mark's cave radio locator, but finding the precise location to drill a well could certainly be one use for this technology.

wyandottecaver wrote:you can do a web search for "cave radio" and get lots of info. Someone with basic electronics and soldering knowledge can generally build one but it usually takes someone more knowledgeable to fine tune it.

Yes, there's lots of information on line about cave radios. When searching, be sure to distinguish between communication (voice or data) and radio location (a constant tone). Two different purposes using different technology and (usually) different equipment. Commercially made cave radios are usually very expensive if you can find any. Home-built versions are not all that common either, and in my experience if you want to build an effective system it will require a little more than just "basic electronics and soldering knowledge."

PS Mark - if you happen to see this post, I was at the CE section gathering at the ICS this year and got to see Brian's latest cave radio which he designed for an Antarctic expedition. Very impressive!