Equinox Emi Solved???

[midalake]

So I thought nothing ventured nothing gained. I have about three blocks of beach where the EMI forces me to turn the sensitivity down to 20. Also sick of hearing all the cell phones coming at me from 20 feet away so......It was not pretty. 

 

Did not know what to expect. I WAS FLOORED!  Not only did I not hear cell phones any more, my EMI issue completely disappeared. I was able to run a solid 22 sensitivity and even 23 with water contact. On the wet sand [no water contact] I ran 24 all the way back. I have NEVER been able to run at 24 on this beach.  Your mileage may very, but I will be out with this again today.

Dave

[Badger-NH]

Now there's product waiting to be marketed. The idea just needs to be incorporated into a fabric cover.

[rvpopeye]

Faraday cage to the rescue !

Good fix .

[PimentoUK]

Interesting, I had some tinkering ideas along these lines myself.

I think it could work better if the shield (foil) was electrically connected to the zero volts / power ground of the electronics. This is accessible in two places, the M12 coil connector, pin 2 ( Transmit cold ) and more conveniently, the USB port. As you look at the rear of the control pod, it's the bottom-right contact. If you carefully cut a piece of PVC electrical insulating tape so it covered the other 3 contacts, leaving just the one exposed, it would make the experiment safer.
As an electronics guy, I have some small sprung-loaded contacts ( similar to those used on the XP Deus coil charging clip), and was going to use one to make the connection, but there's lots of improvised ways to do it.
I had the idea of having a short length of 3mm threaded stud sticking out. The foil would be fitted over this, punching a small hole in it, then a nut screwed on top to clamp the foil, and make the electrical connection. I do have some special solder that is for aluminium, and works OK on kitchen foil, that I could attach a small brass washer to the foil for a higher calibre bodge.

[PimentoUK]

Quote: "First Texas used EMI paint on the T2/F75 connected to ground to help although there are far better technologies now where they can incorporate conductive fibres when moulding the part.

T2/F75 etc coils are moulded from conductive plastic. But there's shielding and there's shielding. A terrific shield is not desirable on a coil, as it stops it picking up metal objects. On the control box, anything from solid metal to low-resistance graphite is useful. The huge weak point in the T2 control-box shield is the massive hole in one side where the LCD is. There are ways of making a see-through screened panel, but it would be cost-prohibitive on a consumer metal detector.

Edit: one possible 'see-through' screen material is the perforated sheet that's inside the glass window of microwave ovens. Next time I see a dumped oven, I may have to do some salvaging.

I suppose I should point out that kitchen foil shields ( and metal boxes ) are not that compatible with 2.4 GHz radio headphone links. For info, the antenna is at the top edge of the control box, running horizontally.

[Joe D.]

I knew i was doing it wrong!! But i make these look good!👍👍

[Joe D.]

    In all seriousness, if you know someone who can sew! You can take an existing cover to them for a pattern to deconstruct! And the foil material out of a soft cooler, which can then be sewn back together, than refitted on the knox!

    Doc's Nox Covers, or another maker, could also sew in a layer in there current line of covers, and already have an existing market established! But that would up the price! 👍👍

[midalake]

13 hours ago, Badger-NH said:

Now there's product waiting to be marketed. The idea just needs to be incorporated into a fabric cover.

 

9 hours ago, phrunt said:

I've been saying this works for some time, glad someone finally tried it and yes it works even better when connected to the ground like Pimento points out.

So I ran the Alum Foil again today. No EMI from cell phones. In fact I had my friend sweep his cell within 5 inches all around the detector and no EMI pulses. 😁

[Valens Legacy]

This time of year you could use the foil, but when summer comes along you better let the unit get rid of the heat.

[FloridaSon]

On 12/22/2020 at 1:01 PM, phrunt said:

I've been saying this works for some time, glad someone finally tried it and yes it works even better when connected to the ground like Pimento points out.

Manufacturers moved away from the big metal boxes which were good for EMI and into plastic housings and very few did anything to mitigate the EMI that the plastic housing is letting in.  A protective cover with a foil type lining would help a little.

First Texas used EMI paint on the T2/F75 connected to ground to help although there are far better technologies now where they can incorporate conductive fibers into the thermoplastics when molding the housing.

Wonder if the foil tape applied in a couple directions might be enough?