Coiltek 15-inch ALL TERRAIN coil for the X-TERRA Series

[Digger]

As some of you are now aware, I was involved in Field Testing the new Coiltek ALL TERRAIN coil for the X-TERRA. Here is a link to part 1of my two-part blog post at Minelab's TreasureTalk:

http://www.minelab.com/usa/treasure-talk/coiltek-15-inch-all-terrain-coil-for-the-x-terra-series-part-1

If you have any specific questions concerning this new 7.5kHz coil or how it performs in the field, I'll do my best to answer them. HH Randy

 

[amberjack]

geese Randy taking your life into your own hands making an offer like that

OK 1st question how does it go on shallow gold i.e small gold rings?

cheers
AJ

 

[leroy1937]

Thanks 4 the feed back
you are the MAN

 

[Digger]

There are a lot of similarities between the "detectibility" of the 10.5 DD at 7.5kHz and the Coiltek 15" DD. Naturally, the larger the ring the more depth you will realize. On small 10 Kt and 14 Kt gold lady's rings, at depths of 5-inches (dirt) or less, it responded very well with what I consider to be my "normal" sweep speed. ((two seconds each direction) As they "got deeper" (past 5 inches), I needed to slow down my sweep speed and "work" the area to get that initial response. Otherwise it would sound like a slight chirp that one might get from bouncing the coil or lifting it a bit as you changed directions of your sweep. Once I honed in on the target signal, it would lock on very well. (it seems I have a tendency to sweep larger coils much faster than smaller coils. I catch myself walking faster as well. Its almost as if the large diameter triggers something in my mind that tells me I have a lot of ground to cover?) Anyway, back to the rings........ I have a few VERY tiny gold "baby's rings" (won't even fit over the end of my little finger) that were difficult to detect at depths exceeding 3-4 inches. But I have to say, that has been the case for all the DD coils except the small 6-inch DD. In fact, two of these small rings were intially detected with the small coil, in damp soil, at a depth of +/- 5 inches. I did do some testing in fresh water sand, but it was all with "planted" targets. As such, with the 705 in Tracking, the results mirrored those I had in my dirt. Hope this helps. HH Randy

 

[amberjack]

had to laugh about the bigger coil go faster thing good to know I'm not the only one.

that sounds pretty good for a big coil with the 7.5kHz on small gold i would be happy with that, its probably going to work better on the same size silver ring? with that frequency? i know its hard to make a coil that will hit everything hard just my thinking it would prob hit harder on silver than gold? did you do any tests on silver the same size as the gold if so how did it fair?

cheers for the help Randy its good to get some incite into this coil.

AJ

 

[Digger]

To me, silver "hits" harder than comparibly sized gold. I have to wonder if it isn't due more to the higher pitched audio response than the actual target itself. Those two small "baby's" gold rings I mentioned registered a +4 and +6 on the 705, producing two of the lower conductive tones. Silver typically registers in the mid-30's to low 40's, thus a higher pitched tone when using multiple tone mode (which I always use). I have found quite a few rings over the years. I'll run some tests on similarly sized gold and silver, and report back the findings. HH Randy

 

[amberjack]

Kool thanks Randy look forward to the results.

AJ

 

[Digger]

Let me preface this post by saying these "air test" distances recorded may not represent actual field "depths" of these items. Nor should we rely solely on these TID numbers to find rings. As demonstrated by this post and several others over the years, TID values are affected by depth of target, "angle" of the target, mineralization factors, adjacent targets, sweep speed etc.

I ran some air tests with the Coiltek 15" DD ALL TERRAIN coil over various sized gold and silver rings I've dug over the years. The top row are gold rings and the bottom row are all Sterling (or .925). Although the "left to right" sequence is based on diameter of the ring, the mass may vary due to the thickness and design factors of each ring. Note that the 5th ring from the left has a broken band. Depending on whether or not the two halves are touching when you scan over a broken ring, the numbers can (and will) vary immensely. I placed a US Mercury Dime at the right, to give an idea as to the size of each ring. The "distance" recorded is a measurement from the target to the bottom of the coil, using Zero Discrimination, Multiple tone, Sensitivity 26, Volume 28 using the internal speaker and is based on repeatable, solid audio responses.

[attachment 205068 ringstopview.JPG]

[attachment 205069 rings.JPG]




Back row, GOLD rings, left to right
1. 10 K Gold Filled TID

 

[morelic55]

I have one of the WOT's reserved when it is released. Can't wait to get to the old pastures that I've gotten several bullets & buttons out of. It's too bad Minelab did not choose to make the "Pro" Coil like is on the Etrac and the other machines, but hey, I'll take the WOT. At least it is authorized my Minelab!!!!


MO

 

[amberjack]

Thanks Randy, you went to a lot of work there its very interesting looking at the depths on gold v silver i would have bet you the silver would have done better just in plain depth lucky i don't gamble that's whats so much fun about this hobby there are so many variables no one person with any one machine can find everything it gives hope to go again and look

that's one thing i see in this test and i have noticed also similar size rings once they have things hanging off them really changes the numbers mostly on gold see ring 4 and 6 numbers are down, well that's just what i see. i guess it puts them out of being round to a different shape, anyway just thinking out loud.

it also shows me silver is more consistent i guess that has to do with the silver being 925 across the board so what ever metal is mixed with the gold defiantly changes readings all put away in the memory bank for latter use.

thanks heaps for the test it does give some info to use in the field

wow the ring with penny gives some age to the ring wonder if they where more upset about the ring or the penny, nice talking piece for sure.

AJ

 

[Digger]

I attribute the "distance" of several of those gold rings exceeding that of the silver rings is due to those gold rings having more mass than the silver rings. The largest silver ring had a lot of stones. The largest gold rings were all gold. JMHO HH Randy

 

[Gaz]

.....you kept that quiet Randy!!!!....

Read the review mate........great........a good, in depth and honest report.....thanks dude.

An NEL Tornado and WOT coil shoot out would be fantastic now!!!!!!

All the best,

Gaz.

 

[Terra1959]

Thanks Digger
I havent been this excited since --I dont know when

 

[Mick in Dubbo]

Thanks for the insight Randy.
I look forward to reading your part 2 take on this coil. it will be a great open area coil.
Mick Evans.

 

[David]

Randy(Digger), thank you very much for the ring tests on the new 15" DD WOT @ 7.5 kHz. This big coil did a lot better on small gold rings than I thought it would being more sensitive than I would have thought, thus be a good coil at the beach for gold rings.

Then from these gold ring tests you did it looks like it would be good for small gold nuggets as well.

You mentioned in your article that the WOT would be good for prospecting. For small gold nuggets(and specimens) it also will be worth a test in C&T Mode and would do even better in Prospecting Mode with more sensitivity and depth on small gold in low trash areas like the bush.

 

[Digger]

You're welcome. And the depth on the small gold rings surprised me as well. But again, keep in mind those were simply airtests, done to compare to what we already know about the other coils available. I'm somewhat limited to the testing I can do here in the Midwest. Although I did use the new coil on freshwater sand, I am not located near a salt water beach. Likewise, Prospecting for gold is not something done around here. In fact, in my State, the only gold I've ever read about being discovered was a very small amount of flour gold found many, many years ago, about 4 hours north-east of here. Hopefully, some X-TERRA forum members who live near the beach or in "gold country" will report back with their findings and suggestions. Thanks for the post. HH Randy

 

[Steve in Idaho]

I have a 15" coil on order from Doc's Detector Supply when he receives them. I hunt gold with my 705 and I will let you know how it does on nuggets. I just wish that I had it at Ganes cr. Alaska in June. I will have to take it up there next year.

 

[Terra1959]

Mines on pre -order
Hope to pick up next Monday ...yeeehaaa