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Emi Issues?


SwiftSword

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I detected an old house in a thickly settled are in Eastern Mass. yesterday and experienced an unbelievable amount of EMI (9" coil). The Deep HC program was unusable, as were pretty much all the other programs (even mono). I did automatic and manual frequency adjustments, turned down the sensitivity, ground balanced. Nothing made a difference. Curiously, the Park program worked mostly fine. 

The houses are very packed together, 30-50 feet apart. Power lines ran on the far side of the street, and there was a drop line running above the front yard. 
 

I noticed similar behavior on the green strip in front of my house. Do power lines across the street have that much of an effect on the Deus II? That would  cut out a whole bunch of my usual sites.
 

Else, does anyone have any suggestions? 

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Would be interesting to compare with an other detector .. To know if only the D2 has an issue or of it is the same for other machines ...

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Thanks for your feedback, I guess as a rule if you are using multiple frequencies there is always the chance of hitting a rouge frequency.

I experienced this a while back when hunting a garden for a lost ring.

Switching to Deus Mono eliminated the problem, so I guess we must be prepared to use a single frequency when there is no MF option.

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On 3/27/2022 at 4:06 PM, SwiftSword said:

I detected an old house in a thickly settled are in Eastern Mass. yesterday and experienced an unbelievable amount of EMI (9" coil). The Deep HC program was unusable, as were pretty much all the other programs (even mono). I did automatic and manual frequency adjustments, turned down the sensitivity, ground balanced. Nothing made a difference. Curiously, the Park program worked mostly fine. 

The houses are very packed together, 30-50 feet apart. Power lines ran on the far side of the street, and there was a drop line running above the front yard. 
 

I noticed similar behavior on the green strip in front of my house. Do power lines across the street have that much of an effect on the Deus II? That would  cut out a whole bunch of my usual sites.
 

Else, does anyone have any suggestions? 

What update is your unit on? I think mine is 11'03'22 I'll double check when I can.?

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Another Commonwealth-er! This time the other one. 😁 Used to work up there.

Again your issue may be underground power lines. Even though I live in an extremely rural area, my house was built in 2008 on a farm that they were going to build a community on, but economy prevailed and it never happened, a farmer bought it. Lucky for me, I've found Spanish silver literally right out my front door. The developer decided to use underground power, so each house would have this big green box near it that ya have to hide with bushes. 🤣 So much for "green". I've got a massive line running from the front yard to the house.

As I told Commonwealthdetector, it's probably a good thing your detector refused to cooperate, especially if you're using DeepHC. Hitting a 760 amp buried power line might hurt a bit🤯

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I received my Deus II on Tuesday and took it out yesterday (Friday) for a couple of hours. The first site I've hammered to death with F75, Nox 800, even had a CTX3030 on it. No EMI problems there, only managed to find a single clad dime. Next went to an old schoolhouse foundation with a high-tension electric cattle fence: EMI was off the charts! This site is notorious for this problem and I've had the same issue with every other detector here. I was hoping the D2 would do better, but not the case. At least I answered that question.

Now, how did tame the machine somewhat? I tried all the different modes with little change. I reduced sensitivity down to around 60 which helped somewhat. I increased reactivity to 5 which helped even more, but that just didn't seem like I was getting good depth, although I found some ridiculous small foil bits. Finally I put the machine in Mono mode and found the 40kHz frequency to mostly ignore the fence pulses. I searched and area I had been over with the Nox a dozen times or more and found a 1916 wheat cent. Last week, and a park in a nearby town, I had major EMI issues with the Nox and ended up running 40kHz on that to tame it as well.

So perhaps not optimal, 40kHz seems to be a frequency to mitigate bad EMI. I plan to try it a several known EMI locations if it ever stops snowing.

 

JP

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I've used 5, 10, and 15kHz on the other SMF detector with great success. However, you lose depth in single frequency on SMF detectors, and the higher the frequency the less it will penetrate the ground. If you have to switch to a single frequency, try it get it as low as you can.

The other thing you lose on the Deus 2 as I've read is the solid IDs.

I've had similar experience in places I've been and really hammered, got one surprise (Gold pin) but for the most part I cleaned house with my other machine. 😀 Best of luck to ya! The D2 is a big change for me.

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1 hour ago, F350Platinum said:

The other thing you lose on the Deus 2 as I've read is the solid IDs.

 

Interesting you say that. The 1916 penny came up around 78-79 while using 40kHz on the D2. It sounded clean and had a small "presentation" which suggested a good target. It's yet another example that target ID alone doesn't always tell the full story, especially when working in degraded conditions.

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On 3/29/2022 at 4:30 AM, Gary XP said:

Thanks for your feedback, I guess as a rule if you are using multiple frequencies there is always the chance of hitting a rouge frequency.

I experienced this a while back when hunting a garden for a lost ring.

Switching to Deus Mono eliminated the problem, so I guess we must be prepared to use a single frequency when there is no MF option.

What if you encounter EMI at a Salt Beach? Are there any tricks?  Different from scans and shifts. 

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