6" 7.5 kHz Coil - Anyone Using It?

[steve herschbach]

Hi,

Seems like the 18.75 kHz DD 6" coil is getting all the kudos. Is anyone preferring the 7.5 kHz concentric 6" for any reason? In theory it should not be beeping quite as much on every little piece of foil and should get a tad better depth on coins due to it being a concentric and a lower frequency.

Steve Herschbach

 

[bfodnes]

Steve.

I bought the DD the minute it came out due to the reviews it got.

Even in the reviews you could see a difference between the DD and CC that did not fit current thinking.

After using the DD for some time I really cant see how a properly working CC can find more " coins" then the DD do. I have friends that have tried both and said the DD is not only finding more but is also more stable in every environment.

Lets say the CC coil is a regular 6" CC, The 6" DD to me is a turbo loaded 6" that do what the CC does in addition to more.

Its just a fabulous coil, it really is.....

 

[Digger]

Steve, I tested both coils and use both coils. I agree that the DD at 18.75 kHz is a bit more sensitive on lower conductive targets like aluminum. But I am not much of a park hunter. On the same token, I don't see any weakness with the DD on higher conductive targets either. IMO, they seem to have similar depth characteristics. Both coils are HOT. And both coils are stable in my soil. I will say that I prefer the DD, due to the separation characteristics inherit in the design. In all fairness, it goes back to one of my original posts concerning the two coils. I happen to have an extraordinary day, the first time I used the DD. Since it worked so well for me, I found myself using it more than the concentric. And, the more I use it, the more I find with it. And, the more I find with it, the more I use it. And so on, and so on, and so on....... If mineralization isn't the issue, I don't think you will go wrong with either. Which is a good thing for those using the X-30, since it only accepts the concentric at 7.5 kHz. HH Randy

 

[steve herschbach]

Hi Randy,

Yeah, I've given the 6" DD a spin and it is a great little coil for sure. My problem is I have a tendency to want to get every coil I can, but the reality is I only tend to use a couple. I guess I am fishing for an excuse to get the 6" concentric also. Really make no sense as I do not coin hunt much anyway. At this point all I ever see myself using much is the 5" x 10" DD and the 6" DD.

Steve Herschbach

 

[bfodnes]

It will be great to hear your review on the 6" DD after you have nugget hunted with it for a while.

It still seems like those who wants a detector to both nugget hunt and to do some coinhunting buy other detectors then th X-T 70

I believe the X-T 70 to be one of the best multipurpose units ever but I dont have any nuggets around, only simulating. LOL

Bjorn

 

[steve herschbach]

Hi Bjorn,

I've been using my GPX-4000 so much for nugget detecting that I've done little VLF detecting this summer, and winter is now here. So maybe next year. The MXT is easily the most popular machine used to find gold nuggets and yet used extensively for other tasks. As a long-time MXT user I can say the the MXT holds no clear edge compared to the X-Terra 70 on gold nuggets. Which machine may do better on nuggets will depend on the location (ground mineralization) and nature of the gold. B.T. indicates the MXT has issues in Australia but in Alaska the MXT shines. I have tested both units time and again against each other on gold and have been unable to tell myself that either one clearly trumps the other for prospecting. I have ended up favoring the X-Terra 70 for general purpose detecting because it has features I desire that the MXT lacks, like multiple tones and notching.

There are people using the X-Terra 70 for nugget detecting but the machine has not seen the marketing push from Minelab for that use whereas White's strongly emphasises the nugget capabilities of the MXT. The fact is the MXT has found many, many POUNDS of gold in Alaska, and it is hard to argue with all that success. I feel the X-Terra 70 is every bit as capable, but there simply are fewer people using it for nugget detecting and so it gets less press in that area.

Steve Herschbach

 

[bfodnes]

Thanks for the info, great confidence booster for all XT-70 users and future buyers.

Regards


Bjorn

 

[B.T]

The 70 is a rocket on gold, as far as VLFs go, and is the best VLF I have ever used on gold.
I would pit it against any other VLF on the market for gold here down under. Even its own brother the Eureka Gold which was specifically designed for nugget hunting. The 70 is/has been a little dark horse for gold and Minelab themselves didnt know how good on it it actually was/is. When I contacted them and told them what it was finding when I got mine I think for a moment they thought I was pulling their leg. Then I sent them some pics with species, nuggets and tiny bits right down to 1/40th of a g. Maybe they would have chrged more for it had they known beforehand

 

[steve herschbach]

Hi B.T.

I'm not sure why a person would want a Eureka Gold instead of the X-Terra 70. The X-Terra is lighter, costs less, and has a much better coil selection.

Steve Herschbach

 

[Digger]

Three very good reasons Steve. But I wonder if someone switching from the Eureka to an X-70 would "miss" the higher 60 kHz frequency for the very small stuff? Any thoughts Steve? Thanks. HH Randy

P.S. By the way, congratulations on the recent Moore Creek discovery. I can only imagine how excited you must be!

 

[steve herschbach]

Hi Randy,

Thanks! Life is good right now, with the best news is I will spend at least half the summer up at the mine looking for gold.

The Eureka Gold has always seemed to me to be optimized for performance at 20 kHz. The 60 kHz mode is lackluster compared to the Gold Bug 2 at 71 kHz or even the White's GMT at 48 kHz. I suspect this is because that unlike the X-Terra, which uses coils specifically tuned for a certain frequency, the Eureka tries to make due with one coil for three frequencies. Long story short any edge offered by the Eureka Gold at 60 Khz over the X-Terra 70 at 18.75 kHz is minimal at best. And with the Eureka you get no small coil option.

One thing I discovered at our mine at Moore Creek is that some machines are more pleasant to use in bad hot rocks than others. There are units like the White's GMT or Eureka Gold which have no silent search discrimination modes. There theory is that you want to hear all targets so you can use the best discriminator made - your brain.

But at Moore Creek you get multiple hot rocks per swing! The Eureka Gold is very noisy with constant sounds off the hot rocks, and this soon gets very tiring to listen to. The only way to get rid of the sounds is to detune the unit to the point to where it is nearly useless for looking for gold.

Units like the Gold Bug 2 in iron id mode, the Tesoro Lobo in disc mode, and the X-Terra 70 in the coin hunting mode all do better at Moore Creek. The hot rocks can be silently rejected, or at worst they respond with pops and clicks. So units like the X-Terra 70 can be much better for working extreme hot rock situations. And you get the bonus of being to work in areas around campsites that are littered with iron and steel trash to good effect, also due to the superb discrimination. With the X-Terra you get full target ID as opposed to the "beep, or no beep" discrimination of the Gold Bug 2 or Tesoro Lobo making it the better choice in trashy areas. The White's MXT is the only real competition in that regard. But right now you can get an X-Terra 70 with two coils for the price of an MXT plus get notching, mutiple tone options, and frequency options (via the coils).

I'm sure not going to argue the merits of the X-Terra 70 versus various $1000 plus units, but for anyone looking for a superb $700 detector should give the X-Terra 70 serious consideration.

Steve Herschbach
Moore Creek Mining LLC