Silver μMax coil question 7" or 5.75" concentric?

[Firefighter42]

Hello all. I have a question for all the experts out there. I have recently come back to the Tesoro fold with a Silver μMax and was looking to add a different coil to it for a very trashy iron infested old home site. I'm looking at either the 7" or 5.75" concentric coils. What are the pros and cons of the 2? Any depth loss between the 2? From what I read the smaller coils give a better tone response on coins. Depth loss is a concern here because when I hunted this place with my x-terra I was finding silver at 6 to 8 inches. Also a side question is it normal for the silver to give a false signal over gravel/rocks in the ground. I never noticed this with my Bandido II μMax or X-terra. Thanks in advance.

P.S. The micro symbol is for you Monte so you wouldn't scald me

 

[joe dirt_1]

I'm far from an expert, but I do have experience with the Silver µMax and the 5.75" coil. I would buy the 5.75" coil first because it proved it's worth to me in an old church yard I have hunted several times with various detectors.
This church dates from the 1890's and according to some research, they held ice cream socials in the church lawn for many years. I have found several indian head pennies, buffalo nickels, and a few mercury dimes, and even a barber half dollar and barber quarter in the same hole
in the lawn. I thought I had it pretty well cleaned out except for a few stray coins here and there....wrong. With the Silver µMax and the 5.75" coil, I started hunting the side lawn of the church, about a 40x100 foot area. My first signal was faint and sweet sounding. At the bottom of a 6 inch deep plug was a worn 1927 mercury dime. I found 4 indian head pennies, 2 buffalo nickels, a few wheat pennies and a gold plated cuff link in that small area that I thought I had cleaned out. One of the indian head pennies was only about 2 inches deep. There was trash in some of the holes that must have masked the coins when using the larger coils. I had patterned this area several times before, but always with a stock coil. From that day on, I made a point to have a small coil for every detector I bought.

I have no experience with the 7" coil, so I can't help you there, but I think it would be a great coil and give a tad bit more depth than the 5.75" coil, but not the surgical precision of the 5.75" coil at cutting through the trash. I'm not so sure the smaller coil gave a better response on coins, but you can isolate targets from the trash much easier than with a bigger coil. Maybe others will chime in on that question. I don't think you are going to be pulling 8 inch dimes with the small coil, but anything up to 6 inches is fair game for the coil. A good set of headphones might add a tad more depth.

I have seen some pea gravel in tot lots cause false signals. It may be because your Silver µMax isn't perfectly ground balanced for the area where your Bandido and X-terra are closer to being balanced to the area.....just a guess. I'm sure someone here can give you a better answer.
I think you will like the 5.75" coil a lot, but if you can, buy them both. A guy can never have enough coils right ?...........HH

Roger

 

[kaolinwasher]

I would use the 7" wide scan, it will be more quite on the gravel , concentrics make a lot of nose when the ground gets bad, at least thats my experience in our gravel road,

 

[Firefighter42]

Thanks guys for the input. I would love to buy them both but that's not in the budget. I've looked on the forum about the Widescan, but you don't see many people using them or for that fact liking them. I find that strange since everyone and their brother with a different brand detector wants a DD coil.

 

[Monte]

In my opinion, the first thing you had right in the question was comparing a 7" and 5¾" CONCENTRIC coil for working in trashier iron areas. I continue to work with all sorts of coil designs and different brands of detectors, and I still am most satisfied with the performance of a good Concentric search coil. Naturally, most know I am also partial to smaller-than-stock coils, so this question I feel is a very good one to be asked, and answered.

Hello all. I have a question for all the experts out there.

Experts? I am not sure any of us are 'experts' but some of us might be a little more 'experienced' to answer your coil question.

I have recently come back to the Tesoro fold with a Silver μMax and was looking to add a different coil to it for a very trashy iron infested old home site.

Well, I'm curious why you came back into the fold with a simpler "turn-on-and-go" [size=small](meaning factory preset Ground Balance)[/size] model rather than one that was more versatile?

Tesoro's, some models working better in dense iron trash than others, are usually the brand-to-beat or compare all others to when it comes to hunting an iron infested site. I have relied on Tesoro detectors since the Inca came out in July of '83 to compare all other motion-based discriminators for hunting ghost towns, homesteads and other places with dense trash, especially iron. I still do, and most of the detectors in my personal arsenal can handle trash well, close to competing with the likes of a Tesoro Bandido II µMAX or other favorites of mine.

I'm looking at either the 7" or 5.75" concentric coils. What are the pros and cons of the 2?

The PROS would be that they are smaller than the stock 8" or 8X9 coils and that provides a little better ability to work in-and-around trash and brush and other challenges. The smaller coils can also 'fit' in between rocks, structures, brush, easier than the 8" and larger coils. Also, the lighter-weight search coils can be more comfortable to use for longer periods, allow us to use a little slower and shorter sweep speed and length as needed. Plus their smaller size can help us work in and around and between junky areas better to help isolate a potentially good target.

The CONS are few, but should be considered. There are basically two negative points, but it's not really about the coil or coil performance, it is more the operator and the errors they can unknowingly make. One: Many people who mount up a smaller coil doubt their ability to get reasonable depth in some areas, and they also make some errors in search coil presentation with smaller coils by not sweeping them slowly enough to isolate some good targets that are partially masked by nearby junk. It's often more of a mental challenge because they know a site appears large and the smaller coil would be insufficient to work the area in a reasonable amount of time .. like they perceive doing with a 'standard' search coil.

Two: A problem arises when using a smaller-than-stock coil because many users feel they need to hurry across a site because that smaller coil just doesn't provide the bigger-coil's coverage and they figure they need to scurry along to try and work the entire area. That creates a problem when using a 2-filter detector, like the Tesoro's, because the 2-filter circuitry is designed for a slow-motion sweep and provides a quick-response, but sweeping too quickly means the ground signal swamps the filters and they can't process it out fast enough to pass a long a target signal. Then they don't find things and blame it on the smaller coil, when the fault is a too-fast sweep speed. That's especially true if hunting over more intense mineralization such as black sand, pea gravel and rocks.

Any depth loss between the 2?

Yes, but minimal and often you wouldn't notice it.

From what I read the smaller coils give a better tone response on coins.

The 'tone' is the same as the detector produces regardless of the search coil mounted, but the audio qualities are better. You can have a crisper or cleaner or more defines audio response, sometimes, with a smaller-than-stock search coil.

Depth loss is a concern here because when I hunted this place with my x-terra I was finding silver at 6 to 8 inches.

If you're getting coins that deep, just keep hunting them up. If the trash level gets too inhibiting, a smaller coil will help work in and around the trash, and often still get decent depth, but I wouldn't compare 'depth' with a standard coil. Let me add, however, that I have a 7" Concentric mounted on my Tesoro Bandido II µMAX and have used 7" Concentric coils on Tesoro's at least 90%-95% of the time since mid-'83 so that's 31 years of relying on a good smaller-size coil and having ample in-\the-field success.

I also use 4½" and 6½" coils on my White's models, and I'm looking for a 5¾" Concentric for my Tesoro's. What! Now, why did I say nice things about the 7" Concentric and then go and say I am looking for a 5¾" Concentric? Am I just trying to confuse you? Heavens no, just pointing out that even between closely-sized search coils there can still be some differences. I have had a couple of 5¾" coils and liked them, but now that I have a 7" Concentric back in my battery, I want to; get a 5¾" Concentric and work them side-by-side in a variety of locations to see if there is any real pronounced difference in performance.

Mentally, I have seen more people feel comfortable with the 7" because it just looks like it is covering a lot more ground than the smaller 5¾", so they feel better about the results.

Also a side question is it normal for the silver to give a false signal over gravel/rocks in the ground. I never noticed this with my Bandido II μMax or X-terra.

Ground Balance, or lack of a functional GB, is what is causing the noisy behavior,. That, or you're over a bunch of coal clinkers.

If you're falsing over gravel and rocks, the GB is too negative. You wouldn't have had the problem with the Bandido II µMAX if properly Ground Balanced. Be aware of this because even if you opened the Silver µMAX up and tweaked the GB with the stock coil to that mineralized content, you might have troubles when you switch to an accessory search coil. An accessory coil might not be an exact match for the setting you have and the result could be a too negative or too positive function.

Due to the way Tesoro's were designed and some of the variance between coils and touch circuitry adjustments, I have seen and owned a lot of Tesoro's that would not work well when coils were swapped around, unless the unit was Ground Balanced. With all of the preset GB models that I have owned, I always preferred to mount the search coil I would usually use [size=small](it's always been the 7" Concentric)[/size] and then tweak the GB over the more mineralized ground I might encounter , then hunt away without any problems.

P.S. The micro symbol is for you Monte so you wouldn't scald me

I wouldn't scald you or scold you for not using it, but I am thnkful that you did use the 'µ' symbol. Without it and the é and the ó I'd have a tough time dealing with the Tesoro model names.

Monte

 

[BarberBill]

Just my own experience backing up Monte - when using a smaller coil I've found it's very helpful to concentrate on a smaller area, making sure you cover it well, then visualize another small or moderate sized area and cover it well rather than trying to cover a whole park, game field or whatever in a hurry.
BB

 

[Monte]

And Monte couldn't agree more! Not only do I like to "think simple" when it comes to detector and coil selection, I also like to "think small" when it comes to search coil selection, for most sites I hunt, and using ANY search coil, especially a smaller-size coil, to "think small" with regard to the area I want to search. I also like to "think short" as it relates to the coil's sweep length, and naturally that means "think smart" when I plan my approach to a site and the manner in which I want to cover it.

Just my own experience backing up Monte - when using a smaller coil I've found it's very helpful to concentrate on a smaller area, making sure you cover it well, then visualize another small or moderate sized area and cover it well rather than trying to cover a whole park, game field or whatever in a hurry.
BB

Sometimes anyone can just get lucky and sweep their coil over a good target. I was hunting my favorite ghost town many years ago and a fellow was there with a first-release Garrett GTI 2500 and that big search coil they came with. He was wandering willy-nilly and the pendulum swing of his search coil was comical. It was very brushy that season, in between and around most of the dense sage brush. I didn't know the fellow as he was just travelling through from out-of-state.

He walked over to ask me if I had any luck yet, since he had been there for a good four hours before me, and other than some rusty stuff, zinc lids off old mason jars, and a small assortment of old shotgun shell bases and some squished cartridge cases he had nothing to show for his efforts. I let him know that I had only been there for maybe half-an-hour, but assured him I have found a fair amount of old coins and neat artifacts hunting a lot of ghost towns [size=small](not telling him specifically how much I have cleaned out of that town by then)[/size], and I asked him how long he had been using that detector? Oh, about four or five days, he replied.

He asked why I was using a much simpler-looking detector [size=small](note 'simple' in that question)[/size], and I told him it has been working well for me in old town sites. Why the smaller coil? Because it made the simple detector work even better in a dense trash environment. He wondered if he could find anything out there with that high-dollar and "fancy" detector with the big-size search coil, and I said the stuff is here, and a metal detector can find it. Even the one you have, but you just have to be lucky and work the search coil over the target.

He had walked over to chat with me and I had just moved into the edge of a fairly open area. He turned to head back toward his vehicle by way of all the dense brush the other side of this clear space and his detector let out with a good loud response [size=small](he didn't buy headphones when he bought the detector)[/size], and after about four hours of nothing but trash, as he turned and headed across the small open area I was about to hunt he found an 1864, I believe, 2¢ piece.

Yes, big coils and the wrong detector and settings for the site could still let a person get lucky, but I'd rather 'gamble' with 'the odds on my side' and work a smaller coil, picturing a dedicated area, and then work to clean it out.

Same town, different fellow and different day. He was older than me by maybe 25 years and wasn't really into learning much about detectors. Forget learning Ground Balance, and even the modest size detectors with 8" coils were frustrating to him. He and a buddy had visited this old town a few times and he had never found a single 'keeper' of any kind. In a competition hunt he found a prize token and won a Bandido, but couldn't figure it out [size=small](the GB)[/size] and wondered if I would make him a trade.

I was a Tesoro Dealer at the time and I offered him a Silver Sabre II for the Bandido II, and for the difference I sold him a 4" coil for about ten bucks. I didn't have an extra 7" Concentric around, and he wanted smaller anyway. Then, I offered him a trip out ghost towning with me. On the way there he told me how "I [size=small](he)[/size] have wandered all over that town and found nothing!" I explained that the town exceeds 100 acres and he needed to just concentrate. Put the Tesoro w/4" to work in a small, dedicated area.

The last building stood there in '51 and maybe '52, but it's been void of structures since then and is just a barren-looking, overgrown desert ghost town. I told him I had just the spot for him to hunt and in the old business district there was some growths of wild rosebushes mixed in with the sagebrush and other vegetation. I physically 'gridded' the area with the wild rose bushes, and some sage brush and told him to keep the Discrimination at the minimum setting and dig all beeps using that 4" coil. I'd check in with him now and then and encouraged him to keep working the little griddle area.

He was surprised at what he was finding after already recovering some .22 rimfire bullets and old cartridge cases, small washers, and all kinds of little ferrous and non-ferrous trash in such a small, confined space. He was also very excited when, after only finding six silver dimes [size=small](Roosevelt and Mercury)[/size] in his 5-6 years of metal detecting, that he could find so much in a small area ... to include a Seated Liberty Half-Dime! A long, several hour day in a small space with a small coil, but it was a great lesson he learned, all while having some unexpected [size=small](to him)[/size] success.

I get asked how I have found so many coins in that old town over the many, many years I have hunted it, and they would say things like "it's so much area, where's the best place to go?" Answer: Anywhere, just pick a spot, kind of grid it off and then concentrate on cleaning it out ... a little at a time.

Monte

 

[Firefighter42]

Thank you Monte for your reply. Your input is always appreciated. To answer to question of why the simple turn on and go of the Silver μMax. It was a budget thing and I wanted to keep it simple. I wish I had never traded my Bandido II. I bought it used on Craigslist for a steal. I was new to metal detecting and when I had an opportunity to "trade up" to a more expensive detector I took it. Live and learn. Thanks again everyone.

 

[Sven]

Like Monte says, when using the smaller coil, concentrate on a small area and not the entire huge property you are hunting.
Get rid of the caffeine gitters that you need to cover the entire area quickly. Think snail pace, relax and enjoy the hunt.
Best advise, short overlapping sweep pattern.
Once you use a small coil for any length of time, those 8x9 coils look like monster coils.
Lots of 7" DD coils being sold.
Tesoro needs to remake those 7" concentric coils since they are making the 7" DD, heck of a lot of people want to buy them. I should have kept the last concentric I bought, ended up selling it as I didn't have a Tesoro
at that time, didn't figure on getting another soon. A few months later, got a nice Bandido. Wish I had that coil.

I have a 6" coil on my Berkut, its a DD, I like that coil. Gotten used to the DD and it actually goes pretty deep and separates nicely. And easy to pinpoint with, using the coil front edge.

 

[BarryL]

This is why I jumped on a 7 inch super 7 for X2 that I found I have two of them great coils They work extremely well in Trashy sites and very lite

 

[Monte]

I really liked the performance, most of the time, and especially the thin profile. Wish I would have kept the last one but the detector buyer just $weetened the offer enough that I let it go. Haven't been able to find another in good working condition.

Monte

 

[CO_T\Huntr]

I have almost a year with my Silver uMax with 8" Concentric and found it's only weakness is in "Target Separation"
as it failed miserably in a simple target separation test....
I would most certainly recommend the 7" Sidescan Coil, though I haven't had the opportunity
to use one or test it's target separation with this test..... (I upgraded recently)
Given the nature, "trashy", of the majority of the sites I frequent Target Separation is paramount
so I believe the Sidescan Coil would be a necessary investment for the Silver uMax......

 

[machineman]

Small coils rock, I think one of the reasons the Compadre is so good is it forced you to use a small coil. I put a connector on my 7" Compadre and my favorite coil is the 5.75". The 7" is what it came with and its a close second. You cant really go wrong with eather but I suggest the 5.75".

 

[Firefighter42]

Thanks for the input everyone. I think I'm going to go with the 5.75" after Christmas. CO_T/Huntr I would like to hear more about the 7" Widescan coil and how it performs when you get some more time with it. It seems not a lot of people use the Widescan coils.

 

[TAB.HUNTER]

Hello all. I have a question for all the experts out there. I have recently come back to the Tesoro fold with a Silver μMax and was looking to add a different coil to it for a very trashy iron infested old home site. I'm looking at either the 7" or 5.75" concentric coils. What are the pros and cons of the 2? Any depth loss between the 2? From what I read the smaller coils give a better tone response on coins. Depth loss is a concern here because when I hunted this place with my x-terra I was finding silver at 6 to 8 inches. Also a side question is it normal for the silver to give a false signal over gravel/rocks in the ground. I never noticed this with my Bandido II μMax or X-terra. Thanks in advance.

P.S. The micro symbol is for you Monte so you wouldn't scald me

General rule of thumb has always been - the larger coil will be more sensitive to larger objects and deeper for larger objects. However, it will be less prone to see smaller objects at greater depths. There are many other reasons that impact your choice. Will you be hunting the same place for the rest of your life? What is "high trash"? What is the average distance between trash objects? Do you have to weasel the coil between trash or can you swing 4'? What are the soil conditions? A larger coil will see more mineralization that can affect your depth. There are some areas here in Nevada where you can drag a magnet on the ground and get iron ore stuck to it. Widescans are less prone to see mineralization the concentrics. For me, I like concentric for separation. I sold the Silver because I couldn't ground adjust it. It was so bad in some areas that it wouldn't see a coin on the ground with ANY coil. This was after I sent the detector in to be brought up to spec. My neighbor, using the Amigo 2, had no problem. Rusty Henry told me it was because the gain was different. That is probably why you are getting false signals.
I have both coils. If I get lazy and just want to haul along one coil, it will always be the five point 7 five (sorry, my five key is stuck). I've found very little difference in depth between the two. On rare occasions I'll swing the 4".
I really liked the Silver but I needed adjustable G.B. The Outlaw fit that bill. You might call Rusty Henry at Tesoro. If he has time, he will give you a butt load of information.