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bigfoot coil
Posted by: lazyboy
Date: January 09, 2010 11:58AM
hey guys, i am about to order the bigfoot coil for my xlt. any comments from a user would be very helpfull.

I would ask Monte on xlt page or whites main forum:detecting:N/T
Posted by: ohio fred
Date: January 09, 2010 03:20PM

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Re: bigfoot coil
Posted by: Dan-Pa.
Date: January 11, 2010 08:24AM
Nice coil with moderate depth that covers a lot of area..Use absolute value on with this coil and your XLT as when pinpointing it cuts the loop in half and pinpoints well with practice. Sort of acts like a windshield wiper for coverage and a Jimmy Sierra product thats been around a long time.Many years ago used one at a planted hunt and did very well however understand they are now banned at many planted hunts as considered unfair advantage with their coverage and easy pinpointing once learned...If you need depth
no depth demon but if you need coverage excellent choice..

Ask somebody else as I never found a liking for the Bigfoot coil.
Posted by: Monte
Date: January 11, 2010 09:12AM
I've used it just a little .... enough to know it wasn't for me. I prefer a round-shaped coil, and I am partial to a concentric coil as well.

I've beach hunted a number of times with fellows using the Bigfoot coil on an assortment of White's models and regardless of what I had in my hand, they NEVER could get the depth I could or pinpoint as quickly, and in some cases with rusty iron they didn't discriminate as well, either.

Most of the time when I encountered them I was using an XLT w/950 or 8", or 5900 Di pro w/950 or 8", a 6000 Pro XL or and XL pro w/950 or 5.3 BlackMax or 5.3 BullsEye, or either a modified Classic III SL or IDX Pro w/950 or 8" or one of the 6" coils (Blue Max 600 or 5.3 BlackMax or 5.3 BullsEye).

Can they provide a little better coverage on the side-to-side sweep? Possibly, IF YOU KEEP THEM IN A CONTINUOUS FRONT-TO-REAR RELATIONSHIP, but since the typical sweep doesn't move a search coil directly left-to-right and then right-to-left in a straight line (usually a "rainbow" appearing sweep) especially with an elongated coil (or any Double-D) the actual electromagnetic field presentation isn't uniform.

For example, I try to keep my side-to-side sweeps in a straight line and about 3-4 ft. in length. I use a concentric coil so the EMF is essentially uniform all along that sweep path.

Many people make a longer, more aching sweep of perhaps 5-6 feet, and if you're using a D-D (wide-scan_ coil, the full coverage is only there when the search coil is mainly directly in front of you. Once that wiper-effect kicks in and the coil is out to the side, the coverage (picture the field coverage a straight line L-and-R from right in front of you) is only a fraction of the total coil potential.

Add to that the fact that it is human nature for many (most?) people to sweep those bigger coils at a faster pace, and in doing so, it is also normal for the feet to move faster in concert with a faster hand/arm movement rate. The result? Poor sweep technique (aka coil presentation or cover age) as the overlapping efficiency goes down the drain on the outward areas of the sweep, and as the left foot leads your twist and coverage usually differs a bit than when your right foot is leading.

People THINK a bigger coil is going to cover more ground, but not the first thing to appreciate is that the EMF doesn't really extend directly straight down from the coil. Only for a shallower portion of the field as the reactive portion of a Double-D design is really more of a bowl shape. The appearance of a bigger coil at the end of the rod and the faster sweep pace (walked) and poorer, less efficient overlapping will cause a lot of territory to be missed.

Using a short-length straight-line sweep, and a concentric coil, it is much easier, and less fatiguing, for me to properly overlap my sweeps and gain the best site coverage with decent depth and responsiveness.

So, preferring a smaller and lighter-weight coil and not hurrying along I usually get better depth and coverage and discrimination ability from a 6", 8" or 950 coil than I do from a larger, non-concentric coil.

Just a personal opinion o course.


Matter of choice..
Posted by: Dan-Pa.
Date: January 11, 2010 09:59AM
Coil has been around for 20 years or so ought to tell you something. Certainly not for everyone but a little practice pinpointing it pinpoints as well as a round coil and with its windshield wiper effect certainly covers a lot of ground. To each his own I would guess and myself have used a lots of units and sort of a stock coil kind of guy but many use acc. coils whether big or small with great success...

Re: bigfoot coil
Posted by: TIM CLARK
Date: January 30, 2010 05:35AM

Re: I would ask Monte on xlt page or whites main forum:detecting:
Posted by: gilfordberry
Date: March 05, 2010 04:53PM
Monte, you obviously didn't use the bigfoot coil enough to learn how to use it. Pinpointing is much faster with the bigfoot coil than with a round coil, even the small 5.3 inch black max. The instructions for pinpointing suggest seeking the null (loss of signal) that occurs when the target is directly under the front-to-back center of the coil. This method is a pain in the a$$. The quick technique is to pinpoint at the front tip of the coil - and at least 5 of 10 times I can hit the coin target dead on with my first probe. As for depth, you are right. And the "target depth" indication is not all that accurate with the bigfoot. (It tends to show targets a little deeper than they really are most of the time.) The bigfoot doesn't give you quite the depth as does as standard 9.5 inch coil, but the loss is not as much as you might think. I have pulled a tiny gold ring at seven inches and a merc at nine inches. The bigger coil will go a little deeper, but most of my hunting is done in parks where deep digging is a no-no anyway, and the bigfoot does cover ground much faster than a round coil. I tend to dismiss your argument about sweeping in an arc vs. back and forth in a straight line - after all, the length of the arc in which a target is acquired is so short that there can be little difference between the slight arc and a straight line. What's important, imho, is not the length of the arc or whether or not you are sweeping in a straight line. What's important is the speed and the overlap. Here's where the bigfoot really shines. It will take you five sweeps with a 9.5 inch coil to cover the same area AT A 6 INCH DEPTH as one sweep with the bigfoot.

The bigfoot does have one fatal flaw, though. Almost everyone that uses them will find that, sooner or later, the seal between the upper and lower plastic covers will rupture allowing moisture to get into the coil. When that happens, your detector will go nuts. I have owned several bigfoot coils for the XLT and this has happened to EVERY one. I finally learned that the repair is pretty easy - just open it up, dry it out, re-glue it and then paint a band of very tough two-part epoxy all the way around the coil where the upper and lower covers join. There is also a problem in that the "ears" where the coil attaches to the lower rod break off if you bump the coil too often. Once again, epoxy is the fix. I just wish Jimmy Sierra would get his bigfoot coil production back on track. I'm in the market for another.

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