AT PRO and EMI

[wheath22]

I got a new AT PRO 2 days ago. Took it out to the Man Cave and put it together, took another quick look at the manual and fired it up. It went crazy,making all kind of racket. I took it outside, ground balanced it and made a few swings. This machine was still chattering like crazy so I tried decreasing my sensitivity, this didn't make any difference. There was no way I could hunt with a machine that was this noisy. I took it back inside to try some air tests, needless to say my air tests were also disappointing, the distance I was getting on different targets was comparable to my ACE 250. Just so you know I am a relic hunter so depth is high on my priority list, that is one of the reasons I bought the AT PRO. Well I was feeling mighty disappointed right about now so I had a few cold beers and went in the house. When I got home yesterday I grabbed the AT PRO and headed to a field I have been hunting. I turned it on and to my amazement there was no chatter, I ground balanced and set my sensitivity wide open, still no chatter. I went down one notch on sensitivity and started hunting. I found a few bullets and the usual junk but the AT PRO operated flawlessly, no chatter at all. I was starting to wonder now what was going on. When I got back home I went back out to the garage and turned on the AT PRO, it went crazy again. The only thing that could cause this was EMI and believe me EMI will screw the AT PRO up, I guess it must be the higher frequency of the AT PRO is more susceptible to EMI because I have never had any issues with the ACE 250. I still need to repeat my air tests but this time it will be away from any power source. Just wanted to put this out there for all you new AT PRO owners. I had seen some posts on the forum about EMI and how it would disrupt a detectors operation but I never expected it to make a metal detector go crazy like mine did...............Bill in NC

 

[Big Boys Hobbies]

Glad it worked out better this time Bill. I was hoping to hear better results after we talked yesterday! Let us know how it goes next time out!

 

[Terry(Mi)]

Its odd how different detectors are compromised by different EMI sources..... back in the 90's I used to hunt alot of boulevard areas in urban areas with my old sov ..... Most of the power lines werent all that bad, but I could always tell when one of the city police cars were coming up the road .....it would jump and chatter so bad Id have turn my phones down ..... I figured it must have been the radars that were doing it, as it seemed to be "directional".... I could hear them coming over 3 blocks away.......police car gets by me, and no more bad EMI....
Another thing to try is go out near some power lines early on a weekday when temps are moderate in the summer, then go back around 6 pm when the temps are hot, and everyones been getting home from work.... different machines will give different results, but its a fact that EMI will be much greater in the heat of the afternoon !

 

[RLOH]

Bill, I think your detector has some problems. I had an almost identical situation. It would work perfect one minute and the next it was going crazy. While in this crazy chattering mode, I tried every conceivable adjustment and nothing worked. By accident, I touched the coil cable a couple of inches before it connects to the control box and it stopped. When I would gently(barely) tap the cable at this point, it would start the chattering again. When it stopped, it was good until is brushed against it again. Mine was sent in with a very detailed description of what I was experiencing and I don't know how it will be fixed. It should be back in the next couple of days. I have heard rumors of a short inside the control box where the coil cable screws in and I have heard that the problem is a bad cable. Try tapping where I had the problem and see if yours is affected. I do believe that once Garrett resolves their problems, they will have a winner in the AT Pro. I will know in a couple of hunts whether it is a thumbs up or thumbs down. R.L.

 

[John-Edmonton]

There's a couple of places where I experienced similar results. It turns out that there were underground electric cables buried there.

 

[INCH]

I had the same experience with underground power lines on my Ace 250, but with the ATPRO, it seemed like more intense , like demonic spirits , so much chatter, but got away from all the underline power and its an angel....

 

[lasergod]

Did you try changing the Freq? Might be a stupid question but is an option! CHeck you manual on emi!

 

[Terry in PA]

I had the same problem with mine when I first put it together. I'm tall and had the lower rod all the way out to the last hole which when wrapping the cable around it seemed like the cable was to short. So that night I took the cable off the rod and made the rod shorter which left more cable to wrap around the rod. I think what happen was I had the cable tight and it was not plugged in all the way because after I plugged the coil back in it ran nice with out going crazy. Something you may want to check out.

 

[wheath22]

When I put the coil on I ran the wire straight up to the top of the first rod and secured it with tie wraps then wrapped it around the rod from there up. I did screw around with the cable thinking that it was the problem but it didn't change a thing. I used the machine some yesterday with no problems, I can shake and twist it and I have no falseing issues and have had none from the start, the machine was just noisy. I did do some more air tests and my depth improved a little. I can get a diggable signal on a 3 ringer at 10-10 1/2'' maybe 11 anything deeper the signal is weak and broken. I can get a good signal on a cuff button at 9'' and a larger button at 10'' so I think that's pretty. I have a 2 year warranty and if this thing screws up again it is going straight back to Garrett. I have talked to some people who say they got some of the first machines and said they had better depth but they also had the fleecing problem, I wonder how they are fixing the problem with the fleecing, turning down the sensitivity maybe? Could that explain why the new machines are not as deep?.............Bill in NC

 

[spiral]

The only EMI I have a big problem with is electric fences.It drives the AT bonkers!The power lines or cell phones don't seem to affect it all that much.My machine has had the fix and was air tested before I sent it in.I seem to get an inch more in depth on various targets since I got it back..