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Has Anyone Tried A GPX Interference Shield?

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Has anyone had any experience with these things? 

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Electromagnetic and magnetic interferences could be extremely annoying when you are looking for that hard to find gold nugget. Most of the noise is picked up by the search coil but a significant level of noise is being picked up as well by the sensitive electronics inside the control box.

The control box is made of aluminium therefore the magnetic field easily penetrates it.

To prove that, approach a magnet to the right side of your detector when switched on. 

Millions of less obvious noise signals are interfering with your detector.  

We have developed this Shield from the best quality material primarily used in sensitive 

medical and scientific electronics. After years of studying and testing different materials we have found this one ticks all the boxes. 

I have revisited the places where I've previously cleaned up and found more gold after installing the shield.

It is 0.35 mm thick, held firmly around your control box by the armrest and  the new improved version with dual layer shielding on the right side is only 175 g!

We have tested it on the GPX 5000 with amazing results such as quieter threshold, better GB, resulting in slightly increased depth.

The shield allows you to increase the Rx gain by a notch or two without compromising the threshold. Use Inverted Response when hunting for big deep nuggets. 

https://www.ebay.com.au/itm/MAGNETIC-INTERFERENCE-REDUCER-SHIELD-FOR-MINELAB-GOLD-DETECTORS/232594646908?hash=item3627b8a77c:g:8lEAAOSwYGFU0bvu

I noticed it on Ebay today while I was looking for a cover for my GPX.

I have noticed I've been able to quieten down my GPX by opening the control box up and scraping some paint away where the shielding touches the casing, on one end they had scraped away paint from one screw point during production, and the other end had no paint scraped away at all by the factory so it's sheilding was basically useless.  By scraping paint away from a few areas on each end of the detector I was able to give the GPX a bit of a noticable quieten down.  I am sure on later models Minelab would of scraped away more paint but as mine is a very early model made in Australia version this wasn't done.

 

 

 

 

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Sounds pretty interesting, if your in an area with heavy EMI, it could be a valuable tool.  I mostly hunt very remote areas of Nevada, so only get the occasional airplane emi, or a random radar blip now and then but nothing steady or repeatable that is worrisome. But that advertised 1-2 points on the gain is tempting.  Most the time my gpx runs very quiet. If you get sunspot emi this would be great too. Lowering noise level on a machine can not hurt for sure. I run the RF chokes on my coil wires near the box,  not sure if it does much but maybe. I notice my GB2 runs considerable quieter after sunset so I think its affected by the sun in the sky. Pretty interesting topic for sure.

Edited by Mxt Sniper
added info
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Well I couldn't resist, after a year I decided to order one ?

I'll have it in a few days.

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Thanks phrunt, let us know if you do see/hear and difference, I am interested too.

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Just now, MSC said:

Thanks phrunt, let us know if you do see/hear and difference, I am interested too.

Will do, it was cheap enough, he has a money back guarantee also and positive reviews from purchasers so I took the gamble.  I was just wondering why dealers aren't selling it, but maybe it's another X-coil type scenario and only the guy making them wants to sell them or something relying again on word of mouth?

I put my pick magnet near my GPX yesterday and it went wild, we'll see what happens when I put my magnet near it once I get the shield I guess.

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I'm sorry but unless this 'shield' is connected electrically to the ground of the detector, its useless (in fact it may actually act as an antenna for EMI) and you will get ground loops. The inside of the GPX is already shielded although I have seen a few that have been opened by others and they have not re-fitted the shielding wire correctly.

As for some of the statements in that write up especially 

Quote

The control box is made of aluminium therefore the magnetic field easily penetrates it.

well the reason they have that case and not a plastic one is so they can be shielded by connecting the case to ground.

AND 

Quote

To prove that, approach a magnet to the right side of your detector when switched on. 

Magnets are NOT EMI. The effect of the earths magnetic field are handled with part of the circuitry that does EF rejection.

I gather they are trying to make it look like a Faraday shield - this cant work in this scenario as there are cables coming out both ends. For a Faraday shield to work, it has to be totally enclosed.

Sorry its snake oil.

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That pretty much sums it up, thanks Steelphase ?

Would soldering a ground wire onto it and then connecting it to the GPX ground help? Or a pointless exercise?

This is the best information I could find on it

https://www.eevblog.com/forum/projects/shielding/

 

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I don't remember how many years ago that it was, but Minelab said to drag a chain to ground the detector from static build up. The reference might be found with some research?

I do know the Aussies did drag a chain, but that was to mark where they had detected before.

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6 hours ago, phrunt said:

Will do, it was cheap enough, he has a money back guarantee also and positive reviews from purchasers so I took the gamble.  I was just wondering why dealers aren't selling it, but maybe it's another X-coil type scenario and only the guy making them wants to sell them or something relying again on word of mouth?

I put my pick magnet near my GPX yesterday and it went wild, we'll see what happens when I put my magnet near it once I get the shield I guess.

Might try an actual Emi source like cell phone, VLF detector, etc.  I suspect snake oil.  Minelab would be making/selling them if they worked I would think.

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12 minutes ago, Tnsharpshooter said:

Might try an actual Emi source like cell phone, VLF detector, etc.  I suspect snake oil.  Minelab would be making/selling them if they worked I would think.

It was this users feedback that got me interested,

I would like to thank you for making available this great innovative product,

 I have a defibrillator implant in my chest. Your shield has a huge difference to the operation of my 5000.

The unbearable noise produced by my heart device has virtually disappeared, something no amount of tuning could do.

I still get interference when i lean forward to sort the target over the coil, (coil problem)

but at least I can pluck the buggers out of the ground again. thank you once again for your innovative product.

One happy camper
Graham

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