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Minelab X-Terra 705


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Yeah, coils aren't cheap. But in all honesty, your concentric is only slightly shallower than the 14.5" Coiltek and heaps easier to swing being better balanced. I'd only outlay money on the big 14.5" if you were consistently hitting deep conductive gullies after a good rainsoaking.

You may gell well with a TDI and appreciate every aspect of them. I prefer the ATX and stock coil to them but hate the sound of them.

But the SDC should keep serving you well. I've relegated mine for one use only now, which it excels at, and will never sell it because I spent a lot modding it to my audio specs. Re sale value of them here is getting so low they aren't worth selling unless your broke. Plus I appreciate the units capability for the purpose they were made for.

But if you sat a TDI, ATX,SDC and 705 on the ground together on any given day ...I'd shoulder the 705 in a heartbeat.

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Wow! thanks for that great lesson, argyle! 

I'm putting the stock 7.5 back on and giving that a go this weekend with the GB tips that you mentioned. I haven't tried the XT-70 in the gold fields as I have the SDC for that and I love how it ignores the hot ground/rocks.It has totally spoiled me in that regard. Right now using a VLF for nugget hunting just has no appeal but I will have to give it a try since reading your post. My current hunting area has very little trash is shallow and the SDC runs super smooth there so using a VLF there never even crossed my mind. Thanks again, argyle!

 

Dean

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 Paul; It is imperative that you follow Argyles instructions, spend several days practicing and  learn how to get the most out of the 705.

  Then come and teach me what you've learned.

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Paul, stay away from big coils for now. Argyle is referring more to the 9" round concentric made by Minelab.

Concentric coils are in my opinion underrated these days. If the detector and ground can handle it I will almost always opt for concentric over DD. In low mineral ground a same size concentric has a depth edge (the blade / cone thing is oversold) and the concentrics identify ferrous trash better, especially bottle caps.

About Search Coils http://www.fisherlab.com/hobby/davejohnson/searchcoilsessayrevised.htm

Search Coil Field Shape http://www.fisherlab.com/hobby/davejohnson/SearchcoilfieldshapeApril2012.pdf

I will toss a vote in for 18.75 kHz for low mineral ground.

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Thx Steve... I will read up on this..

I have a big huge pile of tailings to go thru.... Huge...

Backing off the bigger coils for now----so glad this stuff was brought up by all of you..... saving me money---and time!!!

----I hope Merton doesnt read this because he gets super agitated when us individual detectorists ----(me)

expect everything to be spoon fed to us by those of you who have put in the hours to learn this stuff... research, reseach, research-----

Basically, i knew if i asked on this forum i would get help to get me started in this vlf world

Here's a gem for you Merton.....---- i thought concentric meant mono!!!!

More reading and then boots on the ground Saturday-Tuesday!!!!

Thanks to all of you for your input!

paul

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705 rocks for sure, and tis good fun being broken in by a new detector.

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Iv'e been practicing with the XT70 this week and reading all of the posts on DD and concentric coils and soaking it up. Here are my observations thus far....

Stock ellip 18.75 DD coil- GB# 20-21 in my yard. Can run the sens to 27 and be stable. Great depth. Hits on targets hard. Numbers tend to be "bouncy". PITA pin pointing. I think that this is due to it being a solid coil and I have trouble knowing where the target is under the coil but, with practice, I'm getting much better at it.

 

I put the stock 8.5" 7.5khz concentric coil on yesterday and found that the GB# is 16-18 in my yard and can run the sens to 24 and be stable. Depth is severely decreased compared to the DD and it does not hit on targets nearly as hard. Target separation is better than the DD and pin pointing is MUCH easier as it pin points within the small inner coil and I can mark where the target is because I can see the ground. What surprised me the most was the loss of depth. Very weak signal on a 4" nickel and penny which the DD just bangs out on.

All testing has been done in AM mode and both manual and auto GB and I tried tracking as well. 3 tones.

My questions-

Is this due to the high mineralization? From what I understand the higher the GB# the milder the soil. Or is this due to the targets being planted and not "true" in the ground targets? Or both? I am surprised after all that was said about concentric coils. The DD clearly performs better here (in my yard tests anyway). Thanks.

 

Dean

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The GB number only tells you which kind of mineralisation.

Not the amount.

You can have a low number and still get good depth. And have a high number and not dig anything DEEP.

Where I'm hunting at the moment the soil is greatly affected by moisture/rain and ground balance numbers can easily differ 20 points on subsequent visits. But I always get good depth.

The X-terra 705 can tell you the amount of mineralisation.

1) Ground balance

2) hit auto ground balance button whilst pulling away from the ground, hip height.

3) when the auto ground balance feature sounds off, hit and hold pattern buttons.

She'll flash digits at you XX-XX-XX and this number is relative to the amount of mineralistion it is handling.

Is it usefull,... hmmm yes and no. Another thing to worry about :-)

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scoopjohnb-

Thanks for your reply. What does it matter what type of mineralisation it is? Does the type affect the two coils differently or more so than the amount?

 

Paul-

Good luck tomorrow! I'm heading out with the SDC tomorrow to the spot that has produced nuggets every trip lately. Small but numerous. Sunday I'm heading out with the X-terra and both coils to compare them in real world conditions ( a park).

With the experienced guys extolling the advantages of the concentric coils me thinks my testing must be flawed. Or I'm just such a newbie to the coin shooting and need lots more practice. I think the problem is that my targets are freshly planted and, like air tests, don't give "true" in ground results. If this is the case, then DD coils must perform better in planted target/air tests(?). That is my conclusion thus far. In MY yard anyway. Which probably doesn't mean a darn thing... So, off to the parks I go. What fun! 

 

Dean

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