White's Main Detecting Forum

Welcome! Log In Register
Need help on GMZ.........
Posted by: Ivan
Date: February 21, 2017 02:52AM
I have the chance to get a Whites GMZ detector at an awesome price. I know it is a gold in prospecting........but has anyone ever used one to find in jewelry on dry sand beaches??? Someone told me that there was a guy using one on either Washington or Oregon beaches.Would it be effective in such a use? Anyone own one of these and can put out a few tips on it's operation? Thanx.

Re: Need help on GMZ.........
Posted by: MI-AuAg
Date: February 21, 2017 11:11AM
Hello Ivan,

I have a GMT, which I bought for trips to nugget country. It's basically a more feature laden version of the GMZ, which is a very basic, yet very functional nugget detector. I believe both operate at a very high 48 KHZ.

Since both were designed specifically for hunting very small (sub-gram, down to a few grains) sized natural gold, their use as you describe isn't a good fit, IMO.

When I first purchased my GMT, I went to the Lake Michigan shore (freshwater), and practiced with tiny lead birdshot glued to poker chips in and around magnetite deposits at various depths. The magnetite would mimic ground conditions encountered in real world nugget hunting ares.

When that was done, for the heck of it, I worked the sand a bit, using the standard 6"x9" DD coil. It is essentially a VERY sensative all metal detector that will find tiny pieces of any metal at modest depths. To use it in wet salt sand would be impossible. I am guessing even in dry salt saturated sand it could prove difficult due to it's high frequency. The higher the frequency the more it will respond to mineralization. To attain any decent depths, a larger coil would be necessary, which would compound the sensitivity to mineralization.

Bottom line, I wouldn't buy a GMZ for the purpose of dry saltsand hunting. If I bought one primarily for nugget hunting as the fellow you mention in Washington/Oregon probably did, as that is gold country, it COULD be used on the beach, but, most certainly WOULDN"T be the best option. A general purpose 7-19 KHZ detector would give you much better results for jewelry sized objects IMO.

Sorry, only registered users may post in this forum.

Click here to login