OK Did a little test with the AT PRO...

I have a yogurt cup buried in my yard for my little girl to putt her golf balls in. So I thought I'd give the AT PRO a try at finding a coin under the nail. I ground balanced the detector and set it in custom pro mode with iron disc set at 31. The nail I used rings in at 32 which I also tried during the test. The cup is about 4-5 inches deep. I placed a dime in the cup and placed the nail on top of the cup. The detector either see's only the nail with iron audio on and with iron audio off I only get a snap or pop of junk. It does not see the dime or penny I put under it. Some times it would subtract the numbers of the two targets when I thought it was to add the two together to make a sum greater then the rejected target making a higher number which would give you a tone that would make you stop and dig. May be I'm doing something wrong so please feel free to post. Also someone else may want to try this and let us know what you come up with.

Maybe I am incorrect....but wouldn't just about any detector due to the nature of RF waves from the coil primarily see the nail and not get a clear signal on a good similar sized (mass) target 4-5" below it?



Edited 1 time(s). Last edit at 03/20/2011 12:27AM by TerraDigger.

That is a hard test for any detector.

Terry, please move the dime to one side of the cup and move the nail to the opposite side, just outside and touching the cup. That is a good approximation of one of my simple masked targets in my test bed.

Can the AT Pro see the dime now?

Try the test with no disc and a tone break For iron.



Edited 1 time(s). Last edit at 03/20/2011 05:46AM by godigit1.

Due to the physics of Mother Nature..........all electromagnetic-principle detectors will fail this test............as the signal from the nail is more than 64X stronger than the coin.

The reason I did the test is because on one of the video's that was made from Garrett had a guy holding a nail or screw and got the vid number when he passed it under the coil and ran the iron disc up until it knocked out the nail. Then he held a coin and the nail together and got a higher vid number with both targets together and also a audio response which he said was because the detector added the two target numbers and got a higher vid number which made the detector sound off on the target under the nail which would have been mask other wise.

Do I smell fish....lol..........amazing, historically, how difficult it is for end users to replicate what is seen in many mfg's/dealer's videos/print.



Edited 1 time(s). Last edit at 03/20/2011 05:05AM by TerraDigger.

Terry in pa Wrote:
-------------------------------------------------------
> The reason I did the test is because on one of the
> video's that was made from Garrett had a guy
> holding a nail or screw and got the vid number
> when he passed it under the coil and ran the iron
> disc up until it knocked out the nail. Then he
> held a coin and the nail together and got a higher
> vid number with both targets together and also a
> audio response which he said was because the
> detector added the two target numbers and got a
> higher vid number which made the detector sound
> off on the target under the nail which would have
> been mask other wise.

This is actually a different test then what you performed. I believe because the coin and the nail where together on the Garrett video to detector views them as one unit but the coin pulls the VDI# up higher then the nail alone.

if you get the coin closer to the nail like within an half inch it will start to see it because the signal from the coin is strong enough to start to average in with the nail and overtake the nail signal somewhat ....it does even better if touching the nail....

that's why unmasking is so hard to do for detector's....if the nail and non-ferrous target are not with in certain range of each other and positioned a certain way the target become's oblivious to the detector...

fast shut down between target's and or blending of the target's are the best bet's on unmasking....detector's work off the strongest signal... and report,,,,If a nail is closer to the coil it will cancel out a silver dollar that is 8 inches away or less....

I showed a buddy of mine one time who was playing with a U.S. buckle laying flat on the ground....he said look how far away I hear this buckle...and picked the coil up like 20 inch's and got a beep...While he was doing this I stuck a simple 2 inch long square nail under the coil and the buckle shut up ... he said what did you do I showed him the nail in my hand....the detector was discing out the nail silently but the buckle disappeared too....The nail signal being close to the coil was stronger than the buckle....He was very discouraged from this....but that's the way it work's...

That's why I cant stress enough dig trash out of the way.......detector's are not magical... they all work the same way....


Keith

Took the AT Pro out for it's first real spin today. Hit a spot that I hammered for years. Me and about 1000 other people..lol Any how with in 5 minutes of searching I got a hard hit in the 80's . The signal was loud and clear. From about four inches out came a 1940 Merc. About 10 feet from that one out came a 1920 Merc. Man these silver coins hit hard the second one was about 6 inches down. Not the deep ones I had hoped for but i'll take them. Went around a tree I know I've been around before and got a signal that was read in the 60's and would blip up to the 80's I dug the target and it was a buffalo nickel on edge at around 5 inches. I also found another buffalo right on top the ground. Had a softer high tone and dug around 7 inches and pulled out a wheat penny. Again nothing deep. I did have a little trouble pin pointing some. I 'd get the target under the center of the coil when the bar was all the way to the right like all the other Garrets I've used. But would really have to open the hole a lot bigger to find the target. I had some blips that were around 8 inches that I checked with Iron audio that sounded good at first until checked with Iron audio and heard that Iron sound so I didn't dig them.Small bullets and some shot gun brass drove me crazy at times but not a bad day at all.