Another EMI question.

[Greg (E.Tn)]

I was recently at a CW site where a high tension power line bisected the site. Standing under the lines, you could hear the electrical lines "sizzling."

I was using the F75 Ltd., and fiddling with sensitivity, disc., etc. to find the best settings for those conditions.

My digging buddy was using one of the top of the line White's machines. He had walked off away from the lines for several minutes, and finally returned to where I was digging the occasional 3 ringer.

I told him the power lines were giving me fits, and removed my earphone jack so he could hear the snap, crackle, and pop.

The power lines weren't affecting his machine-at all. He was using the machines standard "relic" program, so I have no way of knowing what the settings were.

So my question: was the difference in interfence where the two machines are concerned a question of sensitivity, or a question of EMI shielding, or lack thereof?

 

[gmanlight]

That's a hard question to answer and can change from location to location.

Just because the Whites is not barking from the EMI does not mean it is not effected.
In a hunt last fall with 2 others , one guy hit a deep target and called us to check it.
I had a Gold Bug SE and the other was a Shadow X3 both run around 19kHz
When we got within 20 feet of each other thy both started barking.
I backed off until the machines went quiet. Then the X3 checked the target but could not hear it .
Then i shut my machine of and the X3 could hit the target.

So EMI can be a pain , but if you hear it at least you know what your dealing with.

 

[sgoss66]

To add to what gmanlight is saying, Tom Dankowski has said before that the WORST kind of EMI is "silent" EMI, in that you don't know it is occurring. I don't know if the White's machine may have been affected "silently" or not, but I just wanted to throw that out there...

Steve

 

[jim tn]

I've got one spot in particular that emi is really bad and has always effected the F 75, T 2, Omega and my F 75 LTD. It is a spot well know for older coins and has be hit by many various detectors. I know of at lest six various makes and models besides mine. Shortly after I got my LTD I worked with it enough on that emi plagued spot to get it running pretty stable and over a two day period worked the spot pretty good. Over those two days, I pulled 6 silver dimes, a Walker half, 1 Buffalo nickel and numerous wheat cents and clad coins from the spot. And none were over 5-6" deep. Obviously, many of those other detectors suffered from emi problems and either didn't know it or didn't want to deal with it. Like as has been mentioned, I want to know when emi is a problem so I can try and make corrections with my detectors. HH jim tn

 

[Greg (E.Tn)]

n/t