3d Dime Rusty Nail Test

[Tometusns]

I’ve got a deus1 and an equinox so I thought I’d play around and mimic the 3-D dime/Rusty nail test. I’ll say that’s a very interesting test to say the least. 
 I used the X-35 9” & X-35 11x13” on the deus and the 6”, 5X10”, 11” and the 15” on the equinox. 
 I tried bunches of different settings on both machines with all the different coils. What I found out was there’s a reason you do multiple directions when searching a location. 
 My deus1 did hit the dime but the vdi numbers were from 04’s to 06’s in that area I couldn’t get a proper vdi no matter what I tried. The 9” coil on 25 kHz was the best. The 13” coil didn’t do as good but still hit it some. 
  The equinox was able to hit the target and give a decent vdi (20-21) solid and repeatable. You would hear the high tone and then zero in on it. Here’s the surprising part or it was to me the 6” and the 5x10” would not hit the dime but the 11” and the 15” would. Both had the same vdi numbers that I stated above. The 11” had a slight edge when it came to zeroing in on the coin.

I need to say getting a good four way hit with either machine was near impossible although there were enough good sounds going around the target to make you want to dig it.
 Today I went to an old park in town that has given up a lot of civil war relics and old coins. I started with the deus1 and 9” coil. I went to the toughest part and all I’ll say is modern trash mixed with iron is tough. I was hoping to find a target that had the very low vdi numbers and the iron tone beside it. That didn’t happen but I did dig a few targets that were mixed in with the junk but hunting in that type of ground conditions was very over whelming. I’m not sure how many sounds were on each swing but rat a tat tat tat rat a tat was what I listened to for that hour.🤪 

 I got the equinox out and hunted with the 5x10” for the remainder of the time I was there. (about another hour) I played mostly with the iron bias settings running it on zero and then adjusting it to see how it changed the sound. My conclusion today was that if I couldn’t tell for sure there were two targets there it was a false signal coming off the end of usually a rusty nail. In other words a good tone with no separation from the iron tone every target I dug today was iron. There had to be a separation for there to be two targets. I’m not sure how many targets I’d have to dig to maybe find a good target with the iron and good signal right together but I’m too old to dig that many holes and find out. lol

  Today was mostly just playing around and trying to possibly learn something. Anyways thanks for reading, good luck and HH! Tom
 
 

[Valens Legacy]

Thanks for sharing this useful information, and I know I will be remembering it for a while.

Good luck and happy hunting.

[EL NINO77]

....Thank you for sharing your insights and information from 3D testing ... as well as field testing.
...
  when detecting in strong iron ..you need to be aware..one fact..and that small DD coils / less than 9 ",, and elliptical coils matches less than 9" / may have a problem detecting deep coin targets between iron ... .

you may be surprised ... what a large target can be practically invisible to a small /or narrow / coil.....

Here is my 3D test for a silver  liberty "half dollar "at a depth of 7cm... below the nails .. using a 5.5x 9.5 "narrow elliptical coil // ..

 

 

The narrow elliptical coil on the ORX cannot pass this test ... even with a coin size such as half a dollar.

..this narrow elliptical coil can only signal the signal in one case ..and it happens you change the sweeping of the coil by exactly 90 degrees ..

If you use a 9 "hf round spool (at 14 khz / .... in this test, the target will be visible when sweeping the whole spool * 360 degrees ... around the target.

My testing of various separation-good detectors and coils shows ... that you need to have a coil of at least 9 "inches.
so that even separation very well detectors can reliably pass such a test ...

..... and here the magic of the 9 "round coil is hidden ...

.....it is the smallest coil that can separate deeply ...

[mh9162013]

So a fair conclusion could be:

The smaller coils on the Equinox (6" and 5x10) might have better target separation than the 11" or 15", but only if the target and iron are on the same plane (and presumably, the target is on a plane above the iron)? 

[GB_Amateur]

13 hours ago, Tometusns said:

...the 3-D dime/Rusty nail test.

Please give details of this setup when you get a chance.  It sounds like it's a standard setup but I'm not familiar with it.  Thanks.

Separation tests are good but given the number of variables in the real world (multiple targets, relative depths, relative transverse distances) it's probably realistically impossible to draw universal conclusions.  But the more tests done, the better knowledge we have, just as long as those results don't lead to an oversimplified, erroneous picture.

[JCR]

This thread illustrates the practical value of testing & experimenting with your detector(s). And it's fun!

[Tometusns]

19 minutes ago, mh9162013 said:

So a fair conclusion could be:

The smaller coils on the Equinox (6" and 5x10) might have better target separation than the 11" or 15", but only if the target and iron are on the same plane (and presumably, the target is on a plane above the iron)? 

  Could be. I’ve sure been thinking a lot about it.🤔

   I think what EL NINO77 said about the nine inch coil makes sense. The larger coils have space between the center bar and the outside of the coil that the smaller coils don’t have. That’s the difference I can see. The nail would be in between the outer and center bar of the coil verses the outer part of the coil directly over the nail when the center passes over the dime.  Perhaps that’s why the larger coils could see the dime and the smaller ones couldn’t. Who knows? 

[Tometusns]

24 minutes ago, GB_Amateur said:

Please give details of this setup when you get a chance.  It sounds like it's a standard setup but I'm not familiar with it.  Thanks.

Separation tests are good but given the number of variables in the real world (multiple targets, relative depths, relative transverse distances) it's probably realistically impossible to draw universal conclusions.  But the more tests done, the better knowledge we have, just as long as those results don't lead to an oversimplified, erroneous picture.

This is what I had set up.

[mh9162013]

22 minutes ago, Tometusns said:

  Could be. I’ve sure been thinking a lot about it.🤔

   I think what EL NINO77 said about the nine inch coil makes sense. The larger coils have space between the center bar and the outside of the coil that the smaller coils don’t have. That’s the difference I can see. The nail would be in between the outer and center bar of the coil verses the outer part of the coil directly over the nail when the center passes over the dime.  Perhaps that’s why the larger coils could see the dime and the smaller ones couldn’t. Who knows? 

This might explain why some people who use the 6" on the Equinox don't notice much of an improvement. 

Imagine we have 3 potential targets:

Target 1 is b/w 2 iron nails, but below the plane the nails are on.

Target 2 is b/w 2 iron nails, but on the same plane as the nails.

Target 3 is b/w 2 iron nails, but above the plane the nails are on.

Presumably:

Target 3 can be hit with any of the Equinox's coils.

Target 1 can only be hit with the larger Equinox coils.

Target 2 can only be hit with the smaller Equinox coils.

If my presumptions are correct (they're probably not), then the smaller coil will offer no benefit in target separation over the larger coils assuming targets are equally distributed amongst the iron trash.

So, how do we explain why smaller coils have better target separation? Maybe it's b/c the above observations are most evident when the trash target is iron and not say...aluminum? Or maybe it's b/c the above results depend on how big the coils is, how small the coil is, how far apart the iron nails are and how far above or below the nails are. So in the end, the small coils perform better than the larger coils in more potential scenarios.

In other words, if you took my above hypothetical "mind experiment," but you expanded it to 100 different possibilities (in regards to how far apart the nails are, how far below or above the dime is, how fast the coils is swung, the size of the coils, etc.), perhaps the smaller coils will come out ahead 55% of the time (or more)? 

It's kind of like how wearing a seatbelt, overall, improves your chances of avoiding serious injury in a car crash. But there are still narrow situations where having a seatbelt in a crash will increase your chances of injury.

TL;DR - a smaller coil helps improve target separation...MOST of the time.

[mh9162013]

This is all very intriguing. I have a proposition:

If someone in the USA has a 6" and/or 10x5 coil they can send me, I'll run them (along with my 11" stock coil) on my Modified Monte's Nail Board and report back with results. Then when testing is done, I'll return the coils on my dime (hahaha, punny).