Baron wrote:
Clint Alexander Inscribed thus:

Great if you are trying to get rescued, a disaster if you want to
find your "stash".
That's funny

It would be for plotting tunnels from gopher, rabbits, etc. But I
don't want to buy COTS, I want to grab all the components myself, put
the circuits together on a few breadboards and make my own casing for
it.

What's important is finding the simple components needed to implement
this type of operation. I've read into ELTs and MELs (Miner Emergency
Locator) as well, and while I have found a few circuit diagrams, they
did not show what antenna is being used and/or how that was connected
to the circuit.

Here is a good example. If I use this oscillator:
http://yhst-27389313707334.stores.ya...1kto68pro.html
(Voltage adjustable from 1KHz to 68MHz)

If we set this to work off of 1-5KHz:
A) How would I figure out what antenna is needed to send this signal
through 10-20ft of dirt and concrete?
B) Where on a circuit would this antenna be attached? (directly
connected to the oscillator and 9-12V with perhaps a resistor
in-between?)

Consider just how big the antenna might have to be at those frequencies.
300,000,000 divided by F in Hz = length in meters.
Using your 5Khz (300,000,000/5000) = 60,000 meters !


for subsurface comms and this sort of application, you typically use a
loop antenna, and accept the terrible efficiency of a physically small
antenna.

Look at the radios used by cavers for communication.