Directional Locators & Frequency Discriminators

AFriend of mine has a DOAK, I want to find one

Afriend of mine, pulled out a DOAK, long range Dowsing, system. I worked for gold, silver, tunnels, water, nickel, copper and various other things. It looked like a black box which 9v power, sensitivity levels, switch and led for on and it had two antenna looking dowsing rods housed in a hand held swivel device. Sure wish to find out where to get one?
*They used to tell me the memory would be the first thing to go.*

I remember the Doak's name, the classified ads he used to run, and having photo's of his products, but at the moment I can't remember if I ever used his products.

I think it worked on Frequency Discrimination, except the Doaks Rod, but I am skeptical that the product had anything more than psychological value (Mental suggestion) for locating water and tunnels.

I don't know where you would find a Doak's locator now. Yours is the first mention I have heard in years.

I wish I could be of more help. Dell

*I can't remember what they said would be the second thing to go* It's probably gone too.