Search coil shapes come in round, slightly out-of-round ('OOR'), elliptical, and 'odd-shaped' physical designs.

Questions:

• Do you have a favorite search coil shape for most of your Relic Hunting needs?

• If more than one shape, please explain what applications you like them for, such as area or conditions of the locations?


► Typically, coil sizes range from about 4" in diameter to 16" in diameter.
These days the majority tend to be a Double-D type but there are still quite a few manufacturers offering Concentric coils. By far the aftermarket search coils are Double-D and very, very few Concentric coils are offered. It used to be a 'standard' coil ranged in size from about 5" to 6½ on lower-end models. and 7" to 8" or 8½" on most average range to top-end models. Almost all were round shaped, and Concentric. A 'larger-size' accessory coil for special use was maybe 10", 12", or the bigger 14", 15" and 16". 'Smaller' coils for general-purpose detectors were 4½" to 7". For the most part we didn't really recognize or class coils in a 'mid-range' size.

Questions:

• Do you have a favorite search coil size for most of your Relic Hunting needs?

• Quite likely you have two search coil sizes for Relic Hunting sites. Could you describe the two favorite sizes you prefer and the types of areas you feel they perform the best for you?

• What sizes of coils do YOU consider to be Small ** Mid-Size ** 'Standard' ** Over-size or Larger?


Basically two types of coil designs are used: Concentric and Double-D.

Questions:

• Have you used both types of coil designs?

• Do you have a personal preference, assuming all manufacturers made both types in all sizes and shapes?


Monte's Answers:

→ Coil Shape: Maybe it's because I spent so long using a round-shaped coil from early '65 that I just got used to them. Today I still look down at a round coil most of the time, or a slightly 'OOR' coil. As of today, I have 8 different models in my Detector Team, and my personal approach to readiness is to keep a selected favorite coil on each detector I want to use. Some, it is the only coil I plan to use, but for a few detectors I might have one or possibly two different coils in my Accessory Coil Tote for special applications. Of my 8 detectors, I have 4 dedicated to Relic Hunting. I keep a round-shaped or 'OOR' coil on a Racer, CoRe, Relic and Bandido II µMAX. There might be times I want to work a fringe area and use a mid-size coil, and if so I can grab ab urban-hunting device, two of which use an elliptical-shaped coil..

I like smaller-shaped coils for Relic Hunting because places I select usually have some dense vegetation, such as sagebrush, thick weeds, tangly growth of other types and sometimes fallen branches and parts of. Can't forget some tight areas in an round standing structures as well as fallen-down building rubble, rocks, cellar hole areas and the like. I can't ignore the unseen, too. I named most of the types of above-ground things we can see when we survey a Relic Hunting site, but the biggest challenge is the unseen.

All of the scattered debris on and just under the surface and down a few inches ... and out of sight, is some non-ferrous metal, but it is the challenging ferrous-based debris that we have to work in and around to find any potentially good targets that might also be partially masked. Not a wise choice to mount a bigger, or even a 'standard' coil. Dealing with all shapes and sizes of common Iron Nails to nuts, bolts, wire from fences, parts from just about anything, and things really get tough when we run into 'rusty tin'. From big full can-size pieces to broken off hunks of tin and down to some areas with abundant amounts of small tin shards. Coil 'shape' needs to work in my favor and not cover too much area, plus be able to fit where I need to work the coil.


→ Coil Size: No doubt most know that I am the biggest fan of smaller-size coils. My first factory produced detector in latter '68 was a White's Ghost Towner BFO that had a small wooden search coil that was 6" in diameter. Back then I was mainly Coin Hunting but I was working a lot of picnic areas where bottle caps were frequently tossed aside. However, the amount of lost coins was plentiful and with so many coins positioned so close together, the smaller-size coils really helped to work in and around and isolate them quickly. My first Ghost Town Hunt was in May of '69 where I got a bitter taste of the dense brush to hamper movement, and the really challenging amount of ferrous, and non-ferrous, debris. The smaller-size coil worked great!

Many decades later I continue to prefer smaller-size coils for most of my Relic Hunting. Of my current 4 Relic Hunting models, the coil size choices are as follows: Small Coils are a 4.7X5.2 'OOR' on a Racer and a CoRe, a 5" on a Relic, and a 6" on a Bandido II µMAX. All are Double-D except the 6" on a Bandido II µMAX.

My opinion on Coil Category:

•Small Coils: Anything with a greater diameter less than 7". Such as a 4", 4½", 5", 5½", 6" and 6½" roundish shape, or an elliptical such as a 3½X6½.

• Mid-Size Coils: A round-shape such as 7", 8" or 9", or an elliptical or 'OOR' shape with a greater measurement from 7" to 9½", to include a 4X7, 5X8, 5X9½ elliptical or the 8X9 'OOR'.

• Large Coils: Any measurement greater from 9½" to 11", like a 10" or 11" round, or a 6X11, 7X11" or 8½X11elliptical.

Anything bigger than those are what I consider to be 'Over-Size' and I have no use for.


→ Coil Types: I use both Concentric and Double-D based upon what a manufacturer makes, combined with how it works on the particular detector selected. They are: Concentric on my Bandido II µMAX, and Double-D on my Racer, CoRe, and Relic.

If I have my choice of coil type, and could get the same sizes I like to work on every brand and model I have ... it would be a Concentric.

Closing comment is this. While I have 8 different models for Relic Hunting, my 'assigned' 4 are my Racer, CoRe, Relic and Bandido II µMAX.

Monte

"Your EYES ... the only 100% accurate form of Discrimination!"
Stinkwater Wells Trading Post
Metal Detector Evaluations and Product ReviewsI'm now 'back home' in Farr West Utah monte@ahrps.org ... or ... monte@stinkwaterwells.com 503-481-8147Detector Outfit: A selection of my chosen makes and models, with the best coils mounted for the tasks I'll take on.F-19 * F-5 * Racer * Racer 2 * V-540 * Relic * Silver Sabre µMAX * Bandido II µMAX * XLTPinpointers: Garrett AT Pro-Pointers .. Headphones: 'Hornet' .. MS-3 Z-Lynk .. ML-80 *** All working well today to make memories for tomorrow. ***



Edited 1 time(s). Last edit at 04/10/2022 07:38AM by Monte. (view changes)