Bench Test

[Anonymous]

I recieved my MXT yesterday so no time to really try it out but i assembled it and tried a bench test . I layed the detector across a 4 foot square cardboard box with no staples in it . 4 feet from the floor , 6 feet from the cieling and 8 feet from the closest wall . I didn't want any metal interference . I placed the ground balance in Lock , set the trigger to the primary center position and set the toggle Mode to Prospecting . I turned the gain on and rotated to the preset . I then adjusted the threshold to a faint hum . I now waved my palm in front of the coil , about 2 inches away and recieved an audible hit tone . Hmmm... Next i placed a small nugget between my fingers and waved my palm in front of the coil again . I recieved the same audio tone that i aquired without the nugget . This is the same nugget i carry to make sure my Gold Bug is working and the Gold Bug will pick this little nugget up in an air test at 8 inches . When i waved my hand with the nugget in it in front of the coil the I.D. registered 70% Iron . What am i doing wrong ? Thanks Art

 

[Anonymous]

Hi Art,
I just did the same test you described with a small nugget (1/4" x 1/4") and got the correct result. I tried it again with some fine gold (Just enough to cover the bottom of a glass sample vial). That time I only got a raise in the noise level above threshold but it still showed chance of iron at 20%. Try increasing gain past preset cause thats where it works best for me for prespecting.

 

[Anonymous]

S.A.T. adjusted?
Turning the unit on in the 'Lock' position establishes a "default" or "factory preset" (same basic difference) of '83.' This could be a much too positive GB, even though we are addressing an 'in air' test.
Also, you should be using all the gain (sensitivity) that you can. The + range not only increases the operating gain, but enhances the audio response (target volume) as well.
Continue to experiment.
<EM><STRONG>Monte

 

[Anonymous]

I noted you said you turned gain to preset which is too low but you did not say you turned the dual control to the hyper sat position---deathwind1

 

[Anonymous]

Tried it again . Turned the gain up to +2 and the SAT to 6 . No problem picking up the half a BB sized nugget , if you can call that a nugget at 2 inches . The threshold was not smooth but i think this will be a different test outdoors in the backyard . What really suprised me was the bench/air test of a few pieces of quartz rock containing visable gold . Not much , but it's there and the MXT nailed it . I found them with the Gold Bug . One piece of quartz has gold that appears to be shot through it under a 10x magnifier and the other piece has a defined line of gold through the quartz about the width of a needlepoint . Thanks for the help guys . I'm sure i'll be back with more questions and maybe a few answers .

 

[Anonymous]

you shouldn't try testing tiny gold samples in your hand. I believe that the really sensitive gold machines, such as the Gold Bug, Goldmasters and others, will pick up the salts in you skin. At least that's what I remember from a few years ago. Perhaps Jim McCulloch or Steve Herschbach can verify this, if they read it.
I remember a test about 30 years ago where some detectors, Compass I think, and maybe others, would pick up the ink in paper money.
Just a few thoughts. Good hunting,
Otto...

 

[Anonymous]

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