Ground base Radar.
Martin

On 8/7/2015 7:41 PM, Leon wrote:
On 8/7/2015 6:20 PM, Electric Comet wrote:
On Fri, 7 Aug 2015 17:20:01 -0500
Leon lcb11211@swbelldotnet wrote:

There are absolutely better ones on the market now, you just cant
afford them.

no kidding
i have not seen any that detect rocks
or ceramic insulators
but i will go look

You might google x-ray.