Emi Mitigation Guide?

[SwiftSword]

I detected an area with maddening EMI on Saturday (front lawn with utility pole in it, and power drop to the house). In trying to adjust to it, I found that I don't actually understand any of the techniques I used to try to get around it. Is there a guide on what to do when dealing with EMI, besides anecdotal "worked for me" hints? I have the 9" coil with v7.1

Here's how it went: 

• Started in Relic mode, sensitivity 95, reactivity 2. Unusable. 
• Did automatic frequency shift scan. - No real improvement
• Ground balance - no improvement. 
• Manually stepped through all the frequency shift values. Went with what appeared to be the least worst.
• Notched out anything below 40 to get at least the noise down. XY screen still shows what's notched out. If there's no signal from the ground, it displays a quivering, vertical ellipsis.
• Detected for a bit, and actually made some finds at 2" - 6". EMI noise still driving me insane though. 
• Tried single frequency. Did the automatic scan (came back 44khz) and also stepped through the frequencies manually. None was quiet, and in any case I don't know what's best for high conductors. 
• Stepped through all the different programs. Park was the only one that seemed a little quieter. Used it for a while, but had no finds, only a bunch of false signals. 
• Went back to Relic. Turned down sensitivity to 90. No change. Turned it down to 60. Slight improvement, but now I'm concerned I'm losing depth. Promptly find a thick iron washer at 8". Isn't low sensitivity supposed to reduce depth? Or is 60 not considered "low"

Bottom line, I was flailing, and clearly don't know how to deal with EMI efficiently. 

Any advice? 

 

P.S. besides a bunch of 1930s wheats, I only had two good finds: an 1837 hard times token with hole, and a GM spinner token. 

[SwiftSword]

Additional question after watching some videos: Is holding down the top-right button to do the noice cancel just a shortcut to the longer procedure of going into Menu > Frequency Shift > Scan? Or does it do something different? 

[F350Platinum]

Yikes! That's some EMI. Worst case it's underground power lines and you're lucky.

The only time I ever have a problem with the Deus 2 is over underground power. It's a blessing of sorts, where I live there is no telling how deep it is. 😵

Single Frequency usually works with my "other" detector. Generally 10 or 15khz is clear. I do have one place where almost nothing works except the Deus 2. 😁

Did you turn off cell phones and any other digital equipment you might have on you? What accessories were you using? What was in the environment?

[SwiftSword]

My iPhone was in my pocket, but that's never been an issue before (and it wasn't once I've moved behind the house). Just the power pole in middle of the front lawn (can't remember if it also had a transformer on it). The houses there all have wifi of course. One of the neighbors could possibly have a wireless dog fence. About 200 feet in front of the house is a church that's built like an office building, flat roof with lots of huge AC units on top, etc. 

As I mentioned, as soon as I moved to the back of the house, things settled quite nicely. 

 

 

 

[F350Platinum]

1 hour ago, SwiftSword said:

Just the power pole in middle of the front lawn

Well there's your problem. 🙂 Surprised it's that bad however. My Deus fares better under power lines, but I still get some noise. Tune it all out? Nope. It will still lock on to stuff tho.

[Denny]

Try bumping up the reactivity.   

[SwiftSword]

14 minutes ago, Denny said:

Try bumping up the reactivity.  

Hm. How would that affect EMI though? It's just going to chop it up more. 

[SwiftSword]

Just watched a video by Paystreak. He's dropping down the audio response to shut up the EMI. I don't understand the correlation there, either. 

I also see he's doing the frequency scan while holding the coil up in the air. I've always understood you're supposed to do it while holding the coil just above the ground. Which is it? 

God, that guy says 20 words for every 2 he actually needs to say 🙄

[F350Platinum]

23 minutes ago, SwiftSword said:

I also see he's doing the frequency scan while holding the coil up in the air. I've always understood you're supposed to do it while holding the coil just above the ground. Which is it? 

I've always held it up. There is a cell tower at one of my permissions that I point it at to help. Doesn't do much. 😀

However, if there's power underground it will go totally nuts, and it might help to hold it toward the ground. Ya might not want to dig too deep tho 😬

Sorry I'm the only game in town at the moment... 🤣 I do use my detectors a lot tho.

Bottom line is you're not always going to get a totally quiet detector everywhere. I run mine hot and don't mind some mild noise.

[SwiftSword]

I'd be fine with "mild noise". But I often feel like I'm in the middle of a Star Wars battle.