Will A Smaller Coil Help Me And My Garrett AT Max?

[mh9162013]

4 minutes ago, kac said:

Yes. I believe what happens is a concentric coil envelops and combines the targets so when targets occupy the same space the lower conductor will drag the higher conductor down. Much like audio where the bass can drown out or reduce the treble.

A dd coil works different where the signal is vertical so targets on top will block targets below.

Between the 2 concentrics that Garrett has for the AT series the 9x12 is ok in open areas with low to moderate trash. It has some descent depth, bit more than the stock dd by just a bit nothing to brag about. It is also a little heavier than the dd.

The smaller 6x9 concentric will do well in high trash areas but will have same or less depth than the stock dd. Smaller DD may work well in wooded areas as it is smaller and easier to work around obstuctions.

So if I went back to the construction site, which coil would you recommend I use? The 6x9 concentric or something else?

[Jeff McClendon]

2 hours ago, mh9162013 said:

I think I see what you're getting at. Let me use some examples to see if I'm understanding you correctly.

Scenario 1: an iron target next to a silver coin and you're using a DD coil - if the coil and metal detector don't have the ability to separate the coin from the iron, the iron will mask the coin. If in zero discrimination mode, you'll hear iron. If in discrimination mode to only hear/see silver coins, you'll hear/see nothing at all.

I would offer another scenario with a dd coil and your 68+ discrimination setting. You may hear short, broken up high tone iron falsing which may sound like a poorly oriented, tiny or very deep high tone non-ferrous target. If silver is actually present, it could be partially masked and its audio response may also be broken, inconsistent and fragmented.

 

The AT series 5X8" DD coil is an awesome coil. Personally, if you are really sold on the AT Max, I would have it and a smaller concentric as Kac has suggested for really trashy areas and in the case of the 5X8" DD, also for its excellent ergonomics combined with AT series detectors.

 

[mh9162013]

7 minutes ago, Jeff McClendon said:

I would offer another scenario with a dd coil and your discrimination setting. You may hear short, broken up high tone iron falsing which may sound like a poorly oriented, tiny or very deep high tone non-ferrous target. If silver is actually present, it could be masked and its audio response may also be broken, inconsistent and fragmented.

The AT series 5X8" DD coil is an awesome coil. Personally, if you are really sold on the AT Max, I would have it and a smaller concentric as Kac has suggested for really trashy areas and in the case of the 5X8" DD, for its excellent ergonomics combined with AT series detectors.

 

Thanks for your insight, Jeff.

Question: Would you recommend the smaller concentric coil (6.5x9) over the 4.5 hockey puck for hunting really trashy sites assuming the primary goal is finding coins?

I think no matter what "specialty" coil(s) I get, I'm going to get the 5x8. 

[Jeff McClendon]

I have never been a fan of Garrett's 4.5 hockey puck. Way to thick for my liking. I would rather just use the 6X9"

[JCR]

5 hours ago, Jeff McClendon said:

I have never been a fan of Garrett's 4.5 hockey puck. Way to thick for my liking. I would rather just use the 6X9"

I think the 4.5" coil is a double stack co planar design. The 6.5X9 is also a great coil and usually gives more stable TID numbers than the DDs.

[dogodog]

I have never run an  at max, But From other machines a concentric rules the day in iron areas. My tesoro's and kruzer with the concentric's unmask more good targets than the DD's. That being said, Swing speed is very important to a concentric's accuracy. There is a fine line of smaller vs larger coils, I have found that a super small concentric just a pain in the ass for coverage and even more precise swing speed. I really like a concentric in the 7'' to 9'' range. I think the 6.5x9 will be perfect for you. Do some dug target testing with old nails and coins to set your disc pattern up. Just try and break your iron so it just gives you a broken response. AND remember big iron and aluminium will fool most coils. Expect to dig some good sounding stuff. Concentrics  are just another tool in your box that you need to take advantage of. Good luck.

[kac]

I would use the 6x9 concentric. I had the 9x12 and separation is difficult and the dd depth is pretty close. I never liked the idea of swinging a hockey puck around, many do well but at that size a concentric will do better in iron and just easier than listening for broken signals.

I spent the majority of last year hunting just iron poluted areas and a dd can be really tricky to snipe out a masked target. I just bought a concentric for my Kruzer which I will be using on the dirty river near me because it is loaded with coal, coke and bog iron. I could use my Tejon but don't want to get it all crapped up hahah.

I would often check targets with all metal mode to get a sense of size/depth on questionable signals. Never really bothered with the id's and basically hunted as iron and not iron as my basis.

[Monte]

You have received a lot of good replies and suggestions from folks with experience, and if I may I'll add mine.  Over 56 years of devoted detecting, and early-on it was primarily urban Coin Hunting because that's what most of the hobby trend was aimed at.  There was occasional trashy conditions, but seldom like we face today.  In May of '69 I went Relic Hunting to my first ghost town, and I continued to hunt iron infested old townsites off-and-off until July of '83, but until then 85% of my detecting was in typical urban sites like parks, schools, easements, and so forth.

In Juley of '83 we got a very good detector for Relic Hunting those old, out-of-the-way locations with dens brush and ample ferrous debris and I switched up to 85% of my time spent Relic Hunting.  For bet success in the very littered sistes you need the following:

• Ample patience

• Good search coil control and coverage by using slow and methodical sweeps

• Use of a well-designed detector with circuitry to handle the good and bad targets with unmasking capability

• Selection of the best search coils to work in, and fit in, all the brush and rubble and assorted targets.

A od detector with  a bad or wrong coil isn't going to be in your favor, not is a good, efficient search coil if it attached to a detector that simply doesn't perform well in very challenging conditions.  Also, be aware tht some detectors were designed with and for a Concentric coil or for  Double-D coils and often will not work very well with the other type of coil  For example, in my personal Detector Outfit I have two Tesoro models that each keep a 6" Concentric coil mounted full-time.  They do not work nearly as well with a DD design.  On the other hand, my Nokta CoRe and Relic devices have their smaller DD coils mounted, and my XP ORX has the mid-size 5X9½ DD attached.  My three Garrett Apex units also have different DD coils attached because, at the present, they do not make a Concentric coil for that model.  I wish they did as I would like their 4½" Concentric coil available for one of the units.

Of the detectors listed in your 'signature' the only one I would care to own is the Garrett AT MAX.  If I had that model I would also own 3 search coils to cover my needs.  The 8½X11 DD for more open areas with sparse targets, such as a beach or plowed field.  The 'standard' coil I would keep mounted for general-purpose hunting is the 'Ripper' 5X8 DD, which is a very enjoyable coil to use.  I have only borrowed an AT MAX a couple of times, nd other than the 5X8 DD or routine use, I liked the 4½" Concentric coil, the "hockey puck" as some call it, because it worked very well in most of the terribly iron littered places.  I wish the coil was a thinner, better-looking design, but it works well and would be the coil I would choose for the toughest places that is smaller than a 5X8 DD.

Just my opinions from prior use.

Monte

[mh9162013]

Thanks Monte!

I think right now, I'll focus on getting the 5x8 coil (unless I find some fantastic deal on the 4.5 hockey puck).