Dealing with EMI?

[Bucket Lister]

I'm encountering a lot of EMI at my current site; it sounds like 3 different Geiger counters all set differently.

What settings can I mess with to reduce/eliminate some or all of the noise?

Or is it hopeless? Tin foil hat? 🤪

 

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[Suncoast Kid]

If you have one of these latest digital detectors, you might have a noise cancel, I'd try that first, obviously make sure your ground balance is correct. Then some have a frequency shift option, increase or decrease the frequency with the shift option to see if you get a quiet spot. Change to a different, or single frequency, if you have a multi frequency detector (SMF).
Last try a different coil. Elliptical coils usually pick up less EMI than a round one.
Decrease your sensitivity a little.
Grab an analog detector, or a different one, if you have more than one.

 

[Bucket Lister]

If you have one of these latest digital detectors, you might have a noise cancel, I'd try that first, obviously make sure your ground balance is correct. Then some have a frequency shift option, increase or decrease the frequency with the shift option to see if you get a quiet spot. Change to a different, or single frequency, if you have a multi frequency detector (SMF).
Last try a different coil. Elliptical coils usually pick up less EMI than a round one.
Decrease your sensitivity a little.
Grab an analog detector, or a different one, if you have more than one.

What you see is what I have--first & only.
That's why I asked here. Still learning this thing.

 

[pepperj]

Simple it seems.
Just need to remember it when I encounter it again.
Electric fencing is the worse.
Gary is easy to understand also.

 

[Suncoast Kid]

Deus II,
Noise cancel- frequency scan
Frequency shift
Change from multi frequency to a single frequency, usually a higher one.
Reduce Sensitivity a little
Increase stabilizer a little
Smaller coil - 9", if you're using a larger one, if you have it.
Unfortunately, it's a wireless unit, and there might be areas that the EMI might be too much for it.

 

[DWerk]

If you want to determine the source of the emi use your coil. Point the bottom of the coil in the air (straight out from you) and make a circle. You are using the coil as an antenna same as a directional antenna for a radio. The emi will be loudest/strongest at/near the direction of the source. Then you will know if it is power line, bad cable tv line, etc.

 

[Bucket Lister]

If you want to determine the source of the emi use your coil. Point the bottom of the coil in the air (straight out from you) and make a circle. You are using the coil as an antenna same as a directional antenna for a radio. The emi will be loudest/strongest at/near the direction of the source. Then you will know if it is power line, bad cable tv line, etc.

Thanks, I know the source--overhead lines--phone, electric, & cable. They inundate 2/3 of the front yard. Once I get out from under them (plus a few feet) the noise quiets down.

Maybe I need a Faraday Umbrella? 🤣

 

[DizzyDigger]

Normally I would suggest some additional shielding around the control box, but with the Deus that's not an option, as there is wireless communication between the coil and the control box.

If you're picking up EMI from the power lines, that is generally 50Hz-60Hz, so the higher in freq. you go, the quieter it should become.

 

[pepperj]

Normally I would suggest some additional shielding around the control box, but with the Deus that's not an option, as there is wireless communication between the coil and the control box.

If you're picking up EMI from the power lines, that is generally 50Hz-60Hz, so the higher in freq. you go, the quieter it should become.

With Deus l HF coil it was possible but with the Deus ll the Freq. only going up to 45.45 kHz

Frequency range available from 4 kHz to 45 kHz: 4.08 to 4.76 kHz - 6.94 to 8.08 kHz - 10.39 to 15.15 kHz - 15.62 to 20.75 kHz - 22.06 to 28.57 kHz - 29.41 to 35.32 kHz - 36.36 to 45.45 kHz.

 

[DWerk]

You may have to contact the power company as well as whoever controls/owns those lines! There are limits of the levels of leakage allowed that must comply with FCC rules/regulations.

 

[Bucket Lister]

I don't know that it's that bad. I've still got to try the suggestions already proffered.

I also won't cause any problems for these folks.

 

[DWerk]

Sometimes letting them know that they may have a problem helps them rather than causing them trouble. A defective line can really lead to additional trouble.

 

[sibbley]

I don't know that it's that bad. I've still got to try the suggestions already proffered.

I also won't cause any problems for these folks.

In my yard with the Deus 2 it's underground dog fence on my neighbor's property. The only way to combat the EMI is Mono mode. In FMF the Deus 2 is useless in my yard.

 

[DWerk]

Only way to beat the underground dog fence is with a nightime shovel or live in the country.

 

[sibbley]

Only way to beat the underground dog fence is with a nightime shovel or live in the country.

I do live in the country, and the flashlight on my nighttime shovel gives me away every time.

 

[sibbley]

I noticed yesterday that Gary Blackwell has come up with a Tekkna program based on Deus Mono for those with EMI troubles. Gave it a try in my yard surrounded by dog fences, works pretty well.

 

[pepperj]

I noticed yesterday that Gary Blackwell has come up with a Tekkna program based on Deus Mono for those with EMI troubles. Gave it a try in my yard surrounded by dog fences, works pretty well.

Great update on using this program and eliminating most of the EMI.

I would love to detect behind Gary as his Z swinging pattern sure misses a lot of dirt.

Using the Tekkna program with zero reactivity yesterday, I could hear the EMI 450ft away when I set the detector down.
I was even over a bank 15 ft down the slope.
Kind of a dirty HV power line running through the area.

 

[sibbley]

Great update on using this program and eliminating most of the EMI.

I would love to detect behind Gary as his Z swinging pattern sure misses a lot of dirt.

Using the Tekkna program with zero reactivity yesterday, I could hear the EMI 450ft away when I set the detector down.
I was even over a bank 15 ft down the slope.
Kind of a dirty HV power line running through the area.

I always think to myself, he's swinging awful fast!

 

[pepperj]

I always think to myself, he's swinging awful fast!

In the open fields, very few targets one can speed up the swing.
Though iron can chirp off a high, going slow it'll produce the grunt or the distinctive iron on the edge of the high.
I still prefer low, slow, 50% lap of the coil.
No race needed.
It's been there for a 100-200+ yrs now so it's not going anywhere soon.

 

[sibbley]

In one of the videos, I watched yesterday, Gary actually addressed his faster swing speed. For the life of me I can't remember what he said about it. I like a slower swing speed too.

Got it, he says if you swing to slow the filters don't have enough time to work and you're not getting a good representation of the target. He says he thinks the machine tells you when you've got the swing speed right. At about 5:02