XP Deus 2 Vs Minelab Equinox 800 High Mineralized Soil & Emi

[Chase Goldman]

 

52 minutes ago, Johnnysalami1957 said:

The coil on a metal detector is an antenna. The more sensitive the antenna the more emi affects it. It's not just the power grid, It's everywhere. One way to shield yourself is distance from the source. alternative methods would be to use shielded cables in the power grid which isn't going to happen. Power is transmitted on uninsulated cables for 100s of miles. Frequency is 60 cycles in the USA and countless harmonics. Power is flowing through the earth and creates potential differences between points in the ground. It seems that metal detectors are designed from 4 to over 60 HZ so they are basically designed to be bothered by this frequency. through no fault of their own. Just like driving a car with the AM radio on near a overhead power line. Receivers are just that designed to receive. If you turn on a TV and have no signal you'll see the white fuzz and hiss. That's the sound of the universe that the receiver is receiving and interpreting as a picture. It's never going away. Just have to tune the sensitivity down or change the frequency of the receiver to an acceptable workable level.

Or move!

You're mostly spot on here, but can't help myself to clear up some technical details.  VLF Induction Balance metal detectors are designed to operate from less than 4 khz to above 60 khz (not HZ).  And the coil as an antenna is not the sole source of EMI susceptibility on a detector.  A lot of near field EMI from cell phones and nearby wifi transmitters (as opposed to power line noise) and even emissions from the coil (in really poorly designed detectors) leaks into the micoprocessor electronics from poor case shielding.  This is especially true of the Nox which doesn't like a cell phone in the vicinity of the control pod.

[Sandheron]

1 hour ago, Chase Goldman said:

No need to keep trying to make SMF work or significantly reduce my detection capability by hanging on to SMF.

I will be detecting a beach with EMI most of the time, so I need the SMF to counter the salt. Catch 22 for my situation. I guess nobody else will be able to deal with it (emi) either so nobody will have an edge. It will be a competition of  who can tune it the best. 

[Chase Goldman]

1 minute ago, Sandheron said:

I will be detecting a beach with EMI most of the time, so I need the SMF to counter the salt. Catch 22 for my situation. I guess nobody else will be able to deal with it (emi) either so nobody will have an edge. It will be a competition of  who can tune it the best. 

You are absolutely right, in that case SMF IS a necessity for salt handling and if D2 cannot handle the EMI in that case then it is a bad situation.  Have you actually encountered the EMI with the D2, or are you anticipating it based on your experience with other SMF detectors like the NOX?

[Sandheron]

4 minutes ago, Chase Goldman said:

You are absolutely right, in that case SMF IS a necessity for salt handling and if D2 cannot handle the EMI in that case then it is a bad situation.  Have you actually encountered the EMI with the D2, or are you anticipating it based on your experience with other SMF detectors like the NOX?

Just from using a nox. I am on a waiting list for a D2. 

To be fair though Chase, the ferrous it is like a carpet of nails at this beach so depth is not really a problem. Now if the emi degrades separation performance, then the problem remains.

[abenson]

EMI issues aside. The Deus 2 is still a pretty good do it all metal detector. But just like every other one out there. It's good at some things and not others.

Like Steve said, I wonder if XP had any testers over here prior to release. Because it appear to me they didn't. Of all the metal detectors I've owed. It's the worst at handling EMI. But as you can see from the second video it can be managed. It's just a pain in the you know what to have to go through so much trouble to calm it down. Noise cancel, then frequency shift, drop the gain, drop the audio response, etc etc.

Still good in thick iron, so I'm keeping it regardless of my EMI and mineralization issues.

[cudamark]

2 hours ago, Sandheron said:

I will be detecting a beach with EMI most of the time, so I need the SMF to counter the salt. Catch 22 for my situation. I guess nobody else will be able to deal with it (emi) either so nobody will have an edge. It will be a competition of  who can tune it the best. 

Here's where using a different detector, such as a BBS machine, might hold the edge. In my area of the U.S., BBS machines do better with EMI than the Equinox. There may be others even better, but, when you need MF for salt water/sand, you're rather limited with choices.

[Johnnysalami1957]

8 hours ago, Chase Goldman said:

 

You're mostly spot on here, but can't help myself to clear up some technical details.  VLF Induction Balance metal detectors are designed to operate from less than 4 khz to above 60 khz (not HZ).  And the coil as an antenna is not the sole source of EMI susceptibility on a detector.  A lot of near field EMI from cell phones and nearby wifi transmitters (as opposed to power line noise) and even emissions from the coil (in really poorly designed detectors) leaks into the micoprocessor electronics from poor case shielding.  This is especially true of the Nox which doesn't like a cell phone in the vicinity of the control pod.

That's called tuition! Thanks, because I wasn't sure about the frequency. I know about the poor shielding in the control pods. That may be easily addressed. 

[GB_Amateur]

On 2/20/2022 at 12:12 PM, Chase Goldman said:

A lot of near field EMI from cell phones and nearby wifi transmitters (as opposed to power line noise) and even emissions from the coil (in really poorly designed detectors) leaks into the micoprocessor electronics from poor case shielding.  This is especially true of the Nox which doesn't like a cell phone in the vicinity of the control pod.

What is the falloff with distance for these two EMI sources you mention -- Wifi and cellphones?  If a detectorist is having trouble with his/her cellphone there is an easy solution.

You mention the ML Equinox as having particular issues with nearby Wifi and cellphones.  I don't notice that too much in parks I've hunted, including when others are nearby.  The park I hunted most of Autumn 2021 had residences on two sides and industry on one side.  On the N side (where there were residences) I did get some EMI when I was within about 75 m distance, but on the S side (more residences) I could get as close as ~30 m and still have no EMI issues.  That sounds like a Wifi issue, but it wasn't so bad I had to go to single frequency -- just turned down the gain from 23 to 18-20.  The park I hunted most of 2020 was more isolated and except for power lines (see below), I had no EMI issues.

As far as cellphone (specifically smartphones as my dumbphone is always in my pocket and never gives me trouble), I don't pick those up in parks even when I'm near (say25-30 m) other park users.  Even when people walk by (within a few meters) I don't notice interference.

When I've had trouble with EMI in parks, it seems to be from local power lines (not the HT tall towers but those very close to residences/businesses/etc.) and again, distance is a big help.  Worst is when I'm in a curb strip and the lines are buried within a couple meters of the surface.  Those are the times I may have to go to single frequency on the Equinox.  My worst ever EMI experience was at a residence whose power line to the house was underground.  No way I could use SMF modes in that location.

Finally, a couple caveats: All of my EMI awareness is when the detector is sounding off.  I've never investigated the silent EMI issue so I suppose I still may be suffering from that even when my detector is quiet as a mouse.  I do run lower recovery speeds (usually 4 on the 800 model) than many and I've noticed lower recovery speeds are less susceptible to EMI, in audio.  But since recovery speed is post-reception processing, in software (right?), that may be a case where it's still hindering detection, but just making it less noticeable.

[Chase Goldman]

Chuck - distance falloff on the near field EMI effects is pretty rapid, a few meters.  The other thing about the cell phone/GHz RF interference is it is readily shielded by your body because of the high transmission frequencies, the EMI is intermittent not continuous, and as far as smart phones are concerned you have three radios to worry about. The cell radio transmitter (most power), the WiFi transmitter (second most power), and the Bluetooth transmitter (lowest power) all in the GHz frequency ranges.  They all have differing effects based on the frequency bands, power. and transmission intervals and based on which radios the user has activated.  That's why you may or may not experience EMI with someone walking by you with a cell phone.  Doesn't change the fact that the control pod is susceptible given the right confluence of factors.  There is obviously self shielding of the detector's own radios (bluetooth/wifi as applicable) but external transmitters may find a way to let their RF leak in. 

I have verified my cell phone as an intermittent source of interference to the Nox, but find that I can run both the D2, Nox, and GPX pretty much interference free with my cell phone placed in a pocket opposite from my swing arm without having to disable the radios. 

My cell phone is an important tool in my detecting kit - I use the GPS for determining site property lines, tracing my swing path through the site, visually/geographically documenting my finds (both what and where), and for communicating with my detecting buddies at a distance.  So I have to make it play nice with my detectors.