I am in the process of testing the DETECH 12.5 inch EXcelerator coil used on the White's MXT. Although I have not completed my entire field test, I would like to share some of my findings with the group. First of all, the coil I am testing is a prototype 12.5 EXcelerator designed for the MXT and the DFX. I am using it on the MXT. Although these coils are not yet commercially available, a phone call to JW at Kellyco should answer any questions you have concerning pricing and availability.
My first reaction to seeing this coil was that it looked to be a bit large to swing on those "all day" hunting expeditions. However, when I connected it to the MXT and adjusted the rod to the proper length, I found it to be very well balanced and extremely light weight. Under 1.5 lbs. I ran the usual airtests with assorted coins and jewelry to see how it reacted and found that the tones and VDI responded similarly to the White's DD coils. Although the packaging indicates that the coil should be used in Relic mode, I found that the Coin/Jewelry mode worked just fine too. Makes me wonder if the notation on the box is for DFX users? I ran it in all three modes, Coin/Jewelry, Relic and Prospecting, and found it to be extremely stable in each mode. I took the MXT outside to my testplot, and using the Prospecting mode, I read the soil in my backyard to be in the low 60's. Switching over to the Relic mode, I was able to locate and properly identify the planted dimes, quarters and nickels at depths varying from 4 inches to 7 inches. Switching to Coin/Jewelry mode, I found all targets again and the VDI was accurate. Since my test plot does not have targets over 7 inches deep, it was time to take it to an abandoned athletic field near my home. I arrived at the field and tested the ground for mineralization. To my surprise, the soil read in the mid to upper 30's. For only being 7 blocks from my house, I was surprised to see such a difference in readings. Then I remembered what one of the techs from White's had told me about mineralization. He said that the substances put into the soil in the past 25 years may have as much to do with the mineralization as the original soil composition itself. Having fertilized my yard every spring and fall for the past 15 years, compared to the old athletic field that has not been fertilized, it seemed logical to have such different readings.
I spent several hours hunting with the coil and found sixteen coins. Two quarters, three nickels, four dimes and seven pennies. None of them very old and none of them over 4 inches deep. That doesn't mean this coil won't detect deeper than 4 inches. It just means I never happened across a deeper coin on this particular outing. Somedays are like that! In airtests, I hit a solid tone on a Kennedy half at over 12 inches. During that specific airtest, I found it interesting that when I pulled the pinpoint trigger back, it would signal on the half dollar to a depth of over 16 inches. I filled a baby food jar with old coins and jewelry and it hit loud at over 20 inches in both Relic and Coin/Jewelry modes.
At the athletic field, I was able to run the MXT at a gain of +2 in both Relic mode and Coin/Jewelry mode,with no instability. Pushing it to the +3 did create enough chatter that I wanted to lower it back to +2. The threshold remained stable in both the Coin/Jewelry mode and the Relic mode. I ran with zero discriminate, switching back and forth between Coin/Jewelry and Relic modes. When running in zero, Relic, I used both two-tone mode and tone-suppressed mode. I found both to be very responsive, but personally prefer the suppressed mode due to the fact that being an old athletic field, it was loaded with "junk" targets (nails, foil, pulltabs) that I was not interested in digging. Even in the suppressed mode, I could hear the junk being nulled out, but found the response time to reset MUCH faster than my Minelab Sovereign Elite. No waiting to "reload". The reset on the MXT was almost instantaneous. Switching to Coin/Jewelry mode, I found the 12.5 coil to run very smoothly. I used both mid position normal and forward position notch. Again, I don't know why the manufacturer says to use Relic mode and lower discrimination levels, but that is written on the box. All I know is that it seemed to work fine for me in either mode and bumping the discrimination level up didn't seem to have any adverse effect on sensitivity or target ID. As to depth, I don't know how deep this thing will go. Although I didn't stumble across any deep coins, I know that I dug a hole over a foot deep in search for an object that read in the low 80's. My digger wouldn't go any deeper without making a mess of the wet soil, so I will leave that one for a dry day. Right now it is 35 degrees and rain. Weather permitting, I will be back out soon and performing some more field tests. If any of you have specific tests you would like me to put this 12.5 coil through, let me know and I will do my best. HH
