Detector for Caves, Cavities???

[starsplitter]

Help! I am trying to identify older twin box detectors that were capable of locating caves, tunnels, cavities under ground. The new ones apparently do do not have this capability. Thanks.

 

[Frankn]

The older Whites and Discovery had cave settings. Basicly what this setting does shift the null. You can do this manually. Here's how. The instructions tell you to set the null setting a little past "0". Well if you set it a little before "0" it gets louder when a void is passed over. The null on a true 2 Box is one of the knobs holding the rod to the receiver. "The perpendicular adj." between trans. & rec. boxes.
In theory, you pick up a background return signal and a target return signal. If you adjest out the backgroung signal, It gets louder when you hit a target, but if you set it on the other side of the null, It gets louder when you loose background signal. ie.You get less background signal from a void than from solid ground. Hope this helps. By the way, that Dents Run story was a hoax. Frank

 

[starsplitter]

Frank... if I understand you correctly, only the older units have this setting capability? Thanks.

 

[DietDewMan]

Jeotech on craigs list

CLICK HERE this guy says his detector is for locating caves, tunnels, cavities under ground, Its a JEOTECH, i have never heard of it thou

 

[Frankn]

Starsplitter, that is correct, but as explaned, you can set an older 2 Box with seperate trans. & rec. boxes to do the same thing.

 

[starsplitter]

Thanks, Frank.

 

[U.K. Brian]

C-Scope did a version of the Discovery model for many years ($1200 new) that finds both hoards and voids ( the CS 9000 HPX). Jeotech machines work and if you go up range will display the void/hoard or whatever on screen but the price is almost prohibitive for most.

 

[starsplitter]

Thanks Diet and Brian.

 

[starsplitter]

Brian... the Jeotech doesn't seem like it will work. I need something that can detect voids 10-30 or more feet down.