Found out that high voltage power lines

[WVaTom]

play havoc on the DFX. Seems to effect it alot more than my old QXT. Even at a 100 yards or better. Still would not trade it though. I am glad I don't detect around them much. Is there any way to minimize this effect?

[bill(de)]

Tom i have the same EMI interference with the DFX and tried detuning to the point of only hitting a dime at 1" and still sustained continuous EMI conditions.I've been running the 5.3 Eclipse and the 3 x6" Shooter with same results.It almost seems if i see power lines i can expect static.To be fair with no EMI the DFX is Excellent.I live in the urban jungle and the DFX can cause a man to HH Bill

[hoser]

Being as I used to be a power lineman, one of the easy tests you can make is by the use of a cheap pocket transistor radio set to the AM band. We used to use one of these for checking for loose tie wires that hold the conductor to the insulator. If the tie wire was loose, you get a lot of static over the radio. The same will hold true for transmission lines. The radio will tell you just how close you can get to the overhead lines before EMI starts to kick in. The higher the voltage, the greater the EMI forces are present and the farther out they emit. So I guess I would say that if you are getting interferrence that you suspect might be caused by power lines, carry a small radio with you just as a secondary checking device before you blame the detector of having a problem. Hope this helps.

[WVaTom]

how do you keep the transmitter from falling out of your pocket? I have bend and crawl often. Thanks for a great tip's you guys. I would add a radio but I have alot,too much, to carry. would it have the same affect on a gps as it would a A.M.radio?

[hoser]

Sorry Tom, I know nothing about a GPS, or what band it runs on. All I can offer ya is that you get the same static as you do with the car radio on Am, and a thunderstorm is close and it pops, and crackles when lightening stikes. If you decide to get a small dual band radio, I would check at garage sales, or one of the dollar stores.

[bill(de)]

Thanks a lot Bill for the AM Radio tip.I'm going to try that the next time i go out.HH Bill

[Tom in SWW]

Hi Folks,

I wonder if running the detector at 15 KHz rather than 3 KHz would make it less immune to HVAC interference? After all, 15 KHz is five times as far away from 60 Hz than 3 KHz is...
Maybe White's needs to put a high pass filter into the unit. That would allow the search frequencies through, while attenuating or eliminating the 60 Hz pickup....
It's not rocket science, and small, low cost filter circuits like this are fairly common in equipment.
I have an inductive probe used for tracing signals on telco circuits that has a "60 Hz" filter switch to eliminate AC pickup.

HH! -Tom