AT Pro 5 X 8 & 8.5 X 11 Coin(s) Air-Test

5 X 8 DD Sens. FULL vs. 8.5 X 11 DD Sens. FULL
40 sq. in. 93.5 sq. in.

* Considering the 8.5 X 11 DD Coil is 134% Larger than the 5 X 8 DD its actual performance IMO is very disappointing in comparison.
My measured % of Gain at FULL Sens. is as follows: 1c = +21%, 5c = +20%, 10c = +14%, 25c = 28%, 50c = 12%, $1 = 12% I would expect at least a 50% gain, wouldn’t you?
Same exact DD Design / Same Manufacturer / Same MT / Same Setting's

* Sorry I can't show all of the numbers because everything got scrambled when I tried to post the spread sheet I made but typically
the gain was only 1" deeper ( Dime, Half & the $1 ) / Penny was 1.5" deeper and only the 25c gainied 2".

If bigger is deeper then I need a 16 X 20.

Not a engineer/electrical guru like some here, but my understanding is that coil depth does not increase in a linear fashion to match the percentage increase in coil size. Maybe someone can give a more technical explanation. I could be wrong.

That is correct.

You could look at it a different way: The (substantially) smaller coil hardly loses depth.

I'll put it another way. That little 5 x 8 coil is wonderful to use. I hunt trashy areas and wooded areas. The stock coil has a shelf in my closet.

Mr. Dankowski & Mr.Goodmore - That little 5 X 8 is a terrific coil and without it I would not be enjoying this hobby nearly as much.

I guess my feelings are that if the 8.5 X 11 were built to the same quality standard as the 5 X 8 it's performance would be much better
than what it actually is. IMO, it performs like an inferior/cheaply built unit, not worththe effort, in comparison.
Anything can be deliberately made in a substandard way.
Less hype and much better performance = Increased sales and Enthusiasm

8" in the air in most cases means 4-6" in the ground e.g. on a dime. Maybe that's why I haven't hit one piece of silver yet?
I am deadly at 3-4" with the $750 worth of equip. I have but beyond that I do not seem to be in the game and would like to be.
I do put in the time and I do go to the areas that should be producing silver finds. However . . .???

This hobby reminds me of the s l o w climb digital cameras took to advance up to todays now acceptable picture resolution(s).
They steadily improved over a period of only 10-12 yrs.

MT Equip. has been evolving for more than 60 yrs. and in some respects seems to be moving backwards ( unless you have $6,000 ? ).
IMO, some models ($700 and more) are nothing more than glorified, expensive stud finders.

Look at how puters have greatly increased cars . . . My 2.0L 4 cyl. has more HP and gets better MPG than the sloppy running 350
2 barrel I had in high school. Because everything is monitored, adjusted and optimized thousands of times per second by the puter.

Computerization has greatly improved many things and could do the same with MT's but we keep plugging along (Pun Intended ) with
basically the same old 1950's low power technology sometimes connected to a LCD Screen to make you believe you have something special.

When the depth indicator on the display tops out at 10" guess what . . . they mean it !!!
I don't hit anything . . . even in the air . . . beyond 10" except a soda can.

Just my 3 cent piece: that 5x8 inch coil has brought old sites back to life for me in such a way that it's the only coill that I use now on my AT Pro. BUT, the stock coil is hitting targets in my test garden that the 5x8 won't barely touch. But I buried those coins and bullets at depths greater than I would find them in real world scenarios. I only did that for my own confidence's sake. Most ALL of the old stuff around here is from 2 to 7 inches deep. And, if it's 7 inches deep, I am surprised because most of the time the real oldies are around 4 inches. The 1890 V nickel was around 4 inches deep and from the imprint that it left in the dirt, I would asssume that it had spent it's entire life in that spot since falling out of a pocket or being lost in a crap game......not counting the sinking that occured due to natural circumstances. Plus, that little coil jujst balances the AT Pro out perfectly. Happy Hunting to my forum friends. Kevin

mcgov51 ...... I have verified the AT-Pro with stock coil (8.5" x 11") will acquire a clad dime in my test-garden to 10". I also felt the quality of the coil was very good. Yet...... I must say this: The initial batch of coils for the AT-Pro had problems. You might have one of these coils; subsequently leading to your reduced performance results.

In one regard...... metal detectors have come a long way. In another regard........... a 1990 model 1266X will ascertain the same depth on a clad dime in inert dirt..... as a 2012 E-Trac or F75 SE. In any case............ due to a small/niche hobby.... the money/demand for greater (more rapid) evolution of metal detection equipment is just not there.

Keith did a very nice write up on this coil vs stock and Gold vs Pro. It convinced me to get one.

THANKS TO ALL of my forum friends for your respectful comments and letting me voice my opinion.
I have the replacement 8.5 X 11 DD coil in front of me still in the box so it's back to the test bench.
I really like this hobby and intend to stick with it.
Jim

P.S. Hit my first Wheat Penny 1956 the other day in the woods. That's the oldest coin I have found
so far. Took me a month and 80 hrs. Where there's Wheaties there should be silver.

McGov, see my recent Omega post. My 11" DD coil which I thought was going to be my *** kicking coil for my area didn't turn out to be. Its not the coil's/mfg fault. There are so many technological variables involved in this hobby that affect performance. I am not a big Garrett fan but I do not think Garrett makes bad coils on purpose. Not to say that your coil can't have a issue, but I don't think thats what's occuring here.
And welcome to Tom's where a person can voice their opinon without concerns of reprisal.