X-TERRA 705 COILS (again)

[harryh31]

I have x-terra 705 with two coils
a) 10" DD 7.5 KhZ
b) 6" DD 18.75 kHz
and search both, farm land and beaches in the UK.
I would like to add a third coil to my collection this being LF coil
Would the difference in results, between the coils I already have, justify the cost, of purchasing a the Minelab 9" concentric 3 kHz coil.

 

[harryh31]

I would like to rephrase the question in my previous message................
Would I benefit from purchasing the Minelab 9" concentric 3 kHz coil, considering the coils I already have ?

 

[Digger]

Mineralization levels are a factor when choosing between concentric and DD coils. Give us an idea of what your ground phase readings are on the DD coils you use, and we could give you a better idea as to whether you'd benefit from the concentric. HH Randy

 

[harryh31]

Hi Randy,
Just carried out some auto ground balancing tests in my back garden.......
6" DD 18.75 kHz coil.............little bit erratic but mainly 25 to 26.
10.5 DD 7.5 kHz coil.............slightly more erratic but mainly in the mid 20's
Hope this info. is sufficient and will help you determine the best way I should proceed.
Harry

 

[harryh31]

Hi Randy
Further to my previous messages would I find any benefit from the 15" coiltek DD 3.75 coil.
Harry

 

[Digger]

With ground phase numbers in the low 20's using a DD coil, it suggests the areas you are hunting have a fairly high level of mineralization. DD coils perform much better in mineralization than a concentric of comparible size. Based on that, I'd stick with the DD's. HH Randy

 

[Digger]

When you go with a larger coil to cover more ground, keep in mind it will have to analyze more ground. So if you were to invest in one of the larger coils for your mineralized soil, it will be important to slow down your sweep speed and maintain optimum Sensitivity and Ground phase settings. HH Randy

 

[MassSaltH2O]

Personally, I would trade that 7.5 kHz coil that you have for a 3 kHz any day.
HH Kev

 

[Old Longhair]

Personally, I would trade that 7.5 kHz coil that you have for a 3 kHz any day.
HH Kev

I wouldn't. That 10.5" MF DD is a great coil that should be in every Xterra owner's arsenal.
Beyond that, Harry is in the UK, where many things about the ground are very different than they are on this side of the pond. Over there the 10.5" MF DD is the stock coil on a 705, and nowhere else. I have to believe that Minelab does it for a reason.

 

[7centsworth]

Personally, I would trade that 7.5 kHz coil that you have for a 3 kHz any day.
HH Kev

I wouldn't. That 10.5" MF DD is a great coil that should be in every Xterra owner's arsenal.
Beyond that, Harry is in the UK, where many things about the ground are very different than they are on this side of the pond. Over there the 10.5" MF DD is the stock coil on a 705, and nowhere else. I have to believe that Minelab does it for a reason.

I agree 100%
I like my 9inch 3khz but the 10.5 7.5khz is a great coil too.

 

[Neil]

Personally, I would trade that 7.5 kHz coil that you have for a 3 kHz any day.
HH Kev

I wouldn't. That 10.5" MF DD is a great coil that should be in every Xterra owner's arsenal.
Beyond that, Harry is in the UK, where many things about the ground are very different than they are on this side of the pond. Over there the 10.5" MF DD is the stock coil on a 705, and nowhere else. I have to believe that Minelab does it for a reason.

That's the DD I went with.....

 

[harryh31]

Hi Travis,
You mention your 9inch 3 kHz coil in a previous message ......is this a DD or concentric coil ?
I want a 9 or 10.5 inch 3 kHz DD coil ,( the 15 inch may be a bit to heavy for me).
I don't seem to be able to locate one in the uk

 

[harryh31]

I want a LF DD 9 inch coil for my 705 for use in UK.
In the event that DD coils for 705 are only available in 6 inch &15 inch sizes, it would appear that the only LF coil 9 inches available is a concentric coil.
My problem is....... should I go for the 15 inch DD 3.75 which is heavier ( but goes deeper and covers more ground per sweep than the 6 inch) or duplicate my existing 6 inch 18.75 kHz.
On studying all the posts on coils for the 705, and taking into consideration the non technical aspect, ie. by using the heavier 15 inch LF coil, the energy used would be compensated by not having to make
so many swings per area covered, ground coverage would be more comprehensive and deeper targets recognised, I'm inclined towards the 15 inch LF coil. Albeit I may have to get a larger digging implement to dig deeper,
M.L. please note :- many retirees (like myself at 85 yrs) finding swinging heavy coils for hours on end can be very exhausting, and more of those retirees that cannot run, swim, dive, ride horses, play tennis etc. etc. are joining the ranks of artefact recoverers, because of its low energy requirements.

 

[Neil]

Harry another consideration is masking and your gonna get more of that with the larger 15" coil.

Ive used the coiltek 15" in the past on a Sovereign. Its a coil with great coverage and depth but its a heavy coil no matter how you slice it and that great coverage it has can hurt you.

Im pretty sure your right on your coil choice so its either the 9" concentric 3khz or the two widescans...6" or 15".

 

[7centsworth]

The nine inch is concentric.

 

[harryh31]

Still haven't made my mind up which way to go.
Further to all the above posts, would anyone consider having both the 6 inch DD 18.75 kHz and the 6 inch DD 3.75 kHz coils.
The 6" dd 18.75 kHz which I have, is very good, lightweight, and I like using it,...... but most of my searching is done for coins and artefact's, so would the 6" DD LF be a better option for me than the 15 inch DD 3.75 coil, I am aware that I would sacrifice depth and obviously area sweep coverage.............but that weight, phew !!!!!!! 28 ozs