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MI Detectors
12-13-2015, 08:15 PM
I've gotten some permissions along a row of houses that have some power lines criss-crossing the street and yards and was causing all sorts of problems for me. Reading about EMI and how to reduce or eliminate, I'm going to reduce sensitivity and try changing to another frequency. Anyone with experience with this have any feedback on EMI elimination. Thanks Dave

MangoAve
12-14-2015, 09:40 AM
What's the machine you are running? Just curious as to the mode of changing frequencies. Was it a simple menu change, or changing the coil like the minelab series? It's prob be better to change frequencies first, so you can run at the normal or higher sensitivity. But you might be forced to change sensitivity too. Trial and error right there in the field. Like one 1862 permission I gotta get back to, the dog fence causes EMI with the Time Ranger. I swapped to the GTI 2500. It was still having an issue with the buried dog fence. So I changed the frequency right there. You can hear/see if the issue goes away the second you change the frequency. The ATP doesn't have a huge available change in frequency like the GTI does.

MI Detectors
12-14-2015, 09:35 PM
Thanks, it's an ATPro. I haven't had the need yet to change frequencies, but by pressing and holding the pinpoint button, you can select one of 4 frequencies to operate with. You just select F1, 2,3,or4. So that's really the only two things I have found that might help, reduce sensitivity and try another frequency. I'll let you know how it works when I get back over there. Thanks, Dave

MangoAve
12-15-2015, 08:03 AM
Good luck. The ATP didn't have a big frequency shift. I think it was mainly added to counter nearby ATP being used vs emi. But it will help a little. Just choose whichever has the least falsing, if you can't eradicate completely. The spot at my permission house next to the side entrance where the old hitching post and brownstone step was located, Lee's ATP was going crazy. It was a prime spot too. I only checked the spot once and never came back because there was only a few clad. Prob filled a little in that area with paving/re-paving the nearby street over the years.

GA1dad
12-15-2015, 12:13 PM
I just picked up a Teknetics T2 SE that has frequency shift capabilities. I only recently learned how they work. On mine there are 7 frequency settings from F1 to F7 and the complete adjustment range is only about a half kHz. That said, Saturday I wandered under a low hanging power line and the machine got real chatty. I made a quick frequency change and danged if the machine didn't quiet right down. I was quite impressed. The manual says it may or may not be effective. I was surprised that such a small adjustment made a difference.

I suspect yours may work the same if the EMI is not too extreme.

MI Detectors
12-15-2015, 07:53 PM
Thanks guys! Yea the frequency shift is small and hopefully it'll help. Hopefully I can get back over there this weekend and try it. Dave