Hockey puck theory

JohnnyPhoenix

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Lots of questions can arise whilst sitting at home under a "stay at home" order.

What are the pros and cons of the smaller coils? I've read that they allow for greater target separation and and from experience, provide access that a larger coil won't. I've also read that they are also more likely to suffer from target masking with co-located targets. Many of us have seen the video where Nox 6" coil is missing the coin under the nail but the standard coil is able to see it. Is this behavior unique to the Equinox, or physics in general.

I guess the answer is "it depends" but would like other opinions. I have hockey pucks for the Nox, F75, and F44, so it's not like I'm going to race out and buy anything (sorry flagging economy) but currently would rather spend time detecting than experimenting. It was a long winter...

JP
 
I know there are going to be many opinions on this but here's mine. Small coils (6' and under) have an advantage when working close to rocks, brush and other obstacles. In general I feel like a small coil only has a 10-20% better chance of unmasking a target when targets are located on the same plane. 10-20% can be huge but you can't cover as much ground with a small coil and so I feel like the trade off is about equal. If I find a bunch of stuff in a small area then yea I'm going to use every coil I have to make sure I get it all.

If targets are located on different planes, like coin under and off the the side of nail the large coil has the upper hand. I think this describes most situations. Unless your hunting an area that is rocky, there's little chance all the targets are going to be on the surface.

I usually have 3 sizes of coils for each of the metal detectors I use. Small 5" x 10" or 6" medium 9" or 7" x 11" and large 11" that's if those sizes are offered. I find myself using the medium and large coils much more than the smaller ones.

I will only use a small coil when I'm in close proximity to obstacles. Which pretty much describes many of the ghost towns I hunt, lots of brush and rocks. If there is open area I will hunt with a bigger coil. If I'm in a park, pasture or field I'm going to grab the big coil every time.

I'll tell you about one experience I had a few years back. Iron loaded pasture at an old fort site, just inside the gate in an area about 20' x 30'. The targets were located from surface to 10" deep. It was so bad I started out using a 7" concentric on my Multi Kruzer and found a few things, mostly melted lead, can't think of anything special found with it. Then I switched to my Racer with a 5" DD coil, more melted lead one small cuff button and lots of square nails that sounded good. The next weekend I went back with the Deus and the 9" HF coil. Now I was starting to find some good stuff. 2 dropped sharps bullets, a kepi button, GS Eagle coat button and lots of melted lead. Final trip with the Equinox and 11" coil. Slowly picking through the iron I recovered 7 more dropped sharps bullets, 2 44 cal round balls, 1 GS coat button and 1 Eagle R button.

Did I remove some of the targets that were masking others? Maybe. Some of these last targets were definitely out of reach of a small coil, others, if in clean ground would have easily got. But the point is just because there's lots of iron, it doesn't mean a small coil is going to be the best tool.

Now you talked about the Equinox specifically. I have both the 6" and 11" coils for it and I've experienced similar situations where the small coil missed stuff that I got with a bigger coil. One site in particular I hunted a nail ridden strip with the 6" coil and got frustrated with all the nails I dug that sounded good. Not one good artifact or coin was dug with the 6" coil. I later returned with the Deus and 9" HF coil pulled out 1 small coin and again with the Equinox 11" coil finding 2 additional small coins. I'm not a real big fan of the small coil but it is useful in some spots.
 
.....Many of us have seen the video where Nox 6" coil is missing the coin under the nail but the standard coil is able to see it. Is this behavior unique to the Equinox, or physics in general.....

He found 1 orientation where the nail masked a coin on the 6" but not the 11" coil. What percentage of the nearly infinite arrangements of coins and trash will a 6" coil provide better separation than a 11" coil? If it's more than half, than the 6" coil is better for that purpose.

I guess now you know the 6" coil might struggle when we have a 5-7" dime in his soil and a nail (old? bent? rusty?) on the surface about 8 inches away, and on the left hand side of the coil (receiver side?), and using whatever settings he had at the time.

Also, he would have hit it fine with the 6" coil if he was gridding the property and approached from 90 degrees more or less. In fact, the 6" coil would have have hit it in the middle of the coil whereas the 11 inch coil might have only hit it on the nose or heel.
 
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Yeah, i somtimes struggle with the value of the small coil. While i have them for all my machines and always have. I'm not so sure the advantage of reduced targets under the coil horizontally out weighs the disadvantages of the lack of vertical targets, in 2020.

As I believe targets continue to sink, iI cant help but think a 8" wide x 5" high coil might be quite effective .
 
Yeah, i somtimes struggle with the value of the small coil. While i have them for all my machines and always have. I'm not so sure the advantage of reduced targets under the coil horizontally out weighs the disadvantages of the lack of vertical targets, in 2020.

As I believe targets continue to sink, I cant help but think a 8" wide x 5" high coil might be quite effective .

I only use the 6" coil in specific situations. I see it as a specialty coil and not simply a smaller version of the stock coil that can be used the same way with the same settings, if that makes sense. I'd be a happier camper if the Nox had a 9 inch coil and a 13 inch coil.
 
All coil decisions are based on LOCATION! I have tripled my finds with the small coil mainly because most of my sites are trashy and surrounded by things like playground equipment,benches,etc. Sooner or later a playing field or huge play area forces another machine with larger coil. One FYI,however-it's really easy to forget to overlap a larger coil!
 
Most of my detecting is done using smaller coils. I hunt in a lot of trash, so I need good separation between trash and good targets.
 
Having multiple targets of varying conductivity under the coil at the same time can effect the quality of your VDI readings and sounds (at least on the single frequency machines I'm using).

Using a smaller coil can help reduce these effects if your willing to sacrifice some depth. I use a 5" x 9" coil at trashy sites and have had very good success with it.

Some people claim that using a smaller coil doesn't make a significant difference but based on my experience I completely disagree....
 
Well, the current social distancing situation will give me plenty of time to play around once I get the "just do it" out of my system. I've got the little "football" coil for the F75 that I've used a few times so maybe I'll play around with that. I honestly didn't observe any improvements with the Nox/6" coil in regards to the electric cattle fence* so I plan to try my CZ-20 just for kicks.

I've got the perfect test site in mind. I played around at a neighbors house for a few minutes earlier in the week. In all metal mode with the Nox it sounded like a machine gun with each swing of the coil! It quickly became apparent that it wasn't worth my time there when I had better options.

*Background: the old school house I'm detecting at is in a cattle pasture surrounded by an electric cattle fence. The Equinox suffers from interference when the fence coil discharges, about once per second. I need to set sensitivity down to 12 or lower to deal with the signal. I tried the 6" coil with limited improvement at a loss of depth. I then tried the F75 with the Nel sharpshooter and it too had to be detuned (sensitivity in the 50's) to work anywhere near the fence. "Near the fence" is within 25 yards, so I'm guessing the charger is a really high powered Gallagher. I inadvertently touched one once...once.
 
Small Coils Can:

-hunt in tight places
-most accurate ID
-greater sensitivity to tiny targets
-greatest sensitivity to all targets
-fastest swing speed
-passes most silly nail tests
-best separation
-lightest
-best tot lot coil
-best nugget shooter coil
-able to get closest to fences, play equipment, iron rebar
-able to accept highest sensitivity in settings
-least expensive
-best trash area hunter
-most under - rated coil!
 

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He found 1 orientation where the nail masked a coin on the 6" but not the 11" coil. What percentage of the nearly infinite arrangements of coins and trash will a 6" coil provide better separation than a 11" coil? If it's more than half, than the 6" coil is better for that purpose.

I guess now you know the 6" coil might struggle when we have a 5-7" dime in his soil and a nail (old? bent? rusty?) on the surface about 8 inches away, and on the left hand side of the coil (receiver side?), and using whatever settings he had at the time.

Also, he would have hit it fine with the 6" coil if he was gridding the property and approached from 90 degrees more or less. In fact, the 6" coil would have have hit it in the middle of the coil whereas the 11 inch coil might have only hit it on the nose or heel.
Good reply, and some of those things that are obvious to more savvy detectorists when we watch some of the vireos that get posted. They (the poster) try to make it sound like the smaller coil (a 6" DD here) is a terrible choice. If I had an Equinox, the 6" DD would be the most-used coil for me. Why? Because I devote the majority of my search time working sites with an over-abundance of ferrous and non-ferrous trash. Plus, many places have very rough terrain or piled / pushed-up soil, sagebrush, weeds, and other brush. And I can't forget the many conditions where I'm encountering building rubble.

In the many decades I have been detecting, and for the bulk of my chosen sites, smaller-size search coils have been my preferred pick. Time and time again, when I have been evaluating a new detector with a 'standard' coil and then continued checking them out with an available smaller coil, the advantage has almost always been in my favor when a smaller-size coil was used.

Since we're referring to a Minelab model here, I'll do the same using their Vanquish 540. I liked it so well I bought a 2nd 540 ro Pack unit. It is only one of two models in my Detector Outfit that I use with a 'standard' or to me a 'larger-size' search coil on. I keep the 9X12 DD on one V-540 because I like the performance in a more open environment with a limited target level.

But I use the other V-540 much, much more with it's smaller-size coil, the 5X8 DD (which to me is a mid-size coil), simply because it fits in some areas better and does a better job of handling most of the densely-littered sites compared to the bigger 9X12 DD.


Now you talked about the Equinox specifically. I have both the 6" and 11" coils for it and I've experienced similar situations where the small coil missed stuff that I got with a bigger coil. One site in particular I hunted a nail ridden strip with the 6" coil and got frustrated with all the nails I dug that sounded good. Not one good artifact or coin was dug with the 6" coil. I later returned with the Deus and 9" HF coil pulled out 1 small coin and again with the Equinox 11" coil finding 2 additional small coins. I'm not a real big fan of the small coil but it is useful in some spots.
What some readers ought to note is that you had better success on a return hunt, not just by using a 9" DD instead of a 6" DD, but they were different designs, used on different brands and models and most likely at different operating frequencies.

That's an example of why I also maintain an Outfit that has more than one detector brand or model and different coil configurations and sizes so that I might select the combination to best handle a site environment. And then to re-hunt a site using a different search coil, or better still a different detector & coil combination.



All coil decisions are based on LOCATION! I have tripled my finds with the small coil mainly because most of my sites are trashy and surrounded by things like playground equipment,benches,etc. Sooner or later a playing field or huge play area forces another machine with larger coil. One FYI,however-it's really easy to forget to overlap a larger coil!
How true, with regard to factoring in the LOCATION in a detector or coil decision, and Location also includes the amount and proximity of both unfavorable and desired metal targets there are to deal with.

You bought up an important point, and I have seen it happen all the time for many years, and those re the folks who go to a larger-size coil don't overlap much, and very often do not over-lap at all! Combined with the fact that many of them sweep too briskly in the first place and all of that 'bad behavior' leads to a lot of missed targets.

I do use two models with a bigger coil, but the rest of my Outfit keep a 5" or 6" or 5X8 or 5X9½ mounted all the time. Smaller-size to mid-size coils, and they easily handle 95% of all the terrain I like to cover.

Monte
 
The Equinox or CTX 6 inch , i havn't used them yet, but the little 5 inch on the F75 SE is fantastic , Earl
I use smaller-size coils the bulk of the time. in the range of at least 90% to most likely 95% of the time, and have favored 5" to 6", or sometimes a 7", for the past fifty years.

I spend the majority of my time hunting older sites with a lot of dense debris, mainly ferrous make-up, but also a lot of urban sites where I'm dealing with metal structures, such as in tot-lots, or hunting littered vacant lots, renovation work or structure tear-down sites. Smaller-size coils are a 'must-have' for me when I hunt.

Just a caution here. I used to use an F75 w/5" DD, and have had 6 or more of the Teknetics T2 series models with the 5" DD coil. In many applications they can work well. And I compared a newer Teknetics T2+ w/5" DD against a friend's Equinox 800 w/6" DD and, without hesitation, the Tek. w/5" DD provided the better handling in a site with multiple lost coins and other non-ferrous targets.

But when compared in a densely-littered site with an abundance of Iron Nails and other ferrous debris, they both paled in comparison with some other detectors that were also using a 5" DD coil. hos included the Nokta CoRe w/'OOR' DD (4.7X5.2), a Relic, Racer 2 and Impact w/5" DD and a Tesoro Bandido II µMAX w/6" Concentric.

It's not simply the search coil size and type, but also the detector it is mounted to and the operating frequency and settings used, combined with a different circuitry design to begin with.

Monte
 
Hockey vs Football: any preference concerning the DD 5” or the 6 1/2 concentric? F75 series, of course. Have a really junky spot across the street from me that a neighbor wants to try out. He has a Radio Shack detector and hasn’t found anything but a pot lid and a spoon so I was going to set him up with something better with a small coil. Maybe the F44 with the 4”, but I don’t know.
 
Hockey vs Football: any preference concerning the DD 5” or the 6 1/2 concentric? F75 series, of course. Have a really junky spot across the street from me that a neighbor wants to try out. He has a Radio Shack detector and hasn’t found anything but a pot lid and a spoon so I was going to set him up with something better with a small coil. Maybe the F44 with the 4”, but I don’t know.
If the "junky spot" across the street has a lot of very closely-spaced targets, and if some of them are ferrous type trash, I'd suggest this:

With what you have mentioned, let him use the Fisher F75 w/5" DD coil. Keep the Disc. as low as possible, even to just barely accept Iron Nails, and instruct him:

► on the Audio Tones
► to sweep the coil Slowly and Methodically
► to Overlap each sweep about 50%
► make short-length side-to-side sweeps of about 24 to 30 inches side-to-side
► and to be patient and recover all Good and reasonable Iffy signals.

I don't care for most smaller elliptical (aka 'football') search coils in heavy trash. And as much as I enjoy using my F44 w/7" Concentric for typical average to open areas for Coin Hunting, that circuitry design is not a good choice when hunting in any ferrous-contaminated site, even with the smaller-size search coils. Of those, my favorite is the 5" DD. the 4" Concentric can work in some places but it has some performance quirks in its design and isn't very good in any abundant-target environment.

Monte

PS: To be honest, since my prefered hunt sites are very Iron Nail littered and also have a lot of other near-by ferrous and non-ferrous debris, I'd be using one of my other detectors rather then an F75 or its older cousin the T2.
 
PS: To be honest, since my prefered hunt sites are very Iron Nail littered and also have a lot of other near-by ferrous and non-ferrous debris, I'd be using one of my other detectors rather then an F75 or its older cousin the T2.[/QUOTE]

"We go to war with the Army we're given" ~ Donald Rumsfeld

I agree the F75 ins't the best in an iron mine, but I'm working with what I have. And I put the 4" on the F44 and horsed around with it a bit and the most complimentary opinion I have of it is it was vague. Today was a balmy 41 out so I'll try both the 5" Fisher and 6" Nox coil tomorrow when it's supposed to get into the mid 50's.

I went and did some exploratory detecting at the site today and did get a couple of decent targets, but no coins. Not sure how "real" the bracelet is. And it's iron infested something awful...
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