Clint Alexander Inscribed thus:

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 !



That's true. Okay -- I obviously would need a lower frequency

Lower frequencies mean longer antenna. :-(
Also since 5Khz is in the audio range of frequencies you might be better
off with a coil based microphone.

to penetrate ground; what would be a workable solution?

I think you need to do some more research. Its easier not to re-invent
the wheel.

What if I took 10ft of antennae and just coiled it so it didn't take
up so much space?

If you take any antenna and reduce its physical size you will also
reduce the amount of energy that it can radiate for any given input. I
forget the rule of thumb, but it goes something like inverse square.
Half the radiation quarter of the distance.


Thanks for all the info!

--
Best Regards:
Baron.