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I rekon ill give it a go Then!
DD coil information and questions
- Thread starter user 794
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condor22
Mike
I have both 11" Mono and DD OEM Minelab GPX5000 coils, also an 8" Minelab Mono and an 18x12 Goldstalker Mono.
I am looking at a larger DD to sweep new patches, for a first quick look;
Coiltek do the 14" round, the 17x11 elliptical
Minelab do a 15" round and an 18"round.
My questions are;
What (and why) would others pick if only one of the above? (Mainly Vic Goldfields)
&
Are there any other choices?
I am aware of the difference in magnetic field and the area calculation differences of round vs eliptical
I am looking at a larger DD to sweep new patches, for a first quick look;
Coiltek do the 14" round, the 17x11 elliptical
Minelab do a 15" round and an 18"round.
My questions are;
What (and why) would others pick if only one of the above? (Mainly Vic Goldfields)
&
Are there any other choices?
I am aware of the difference in magnetic field and the area calculation differences of round vs eliptical
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The only DD I would bother using would be the 14" coiltek AI.
DD
DD
As far as patch finders go you cant beat a large mono loop, my weapon of choice is the Coiltek 24" x 12" UFO, it's an oldie but a goody:
http://www.gold-net.com.au/archivemagazines/aug01/49607934.html#5
In terms of DD coils I can recommend the Coiltek 12" x 8" Platypus this is what I run on my SD2200Dv2, it's my favourite coil, very quiet, very sensitive, good depth:
http://www.coiltekmanufacturing.com.au/12by8-dd-pro.html
Good luck with your hunting
http://www.gold-net.com.au/archivemagazines/aug01/49607934.html#5
In terms of DD coils I can recommend the Coiltek 12" x 8" Platypus this is what I run on my SD2200Dv2, it's my favourite coil, very quiet, very sensitive, good depth:
http://www.coiltekmanufacturing.com.au/12by8-dd-pro.html
Good luck with your hunting
condor22
Mike
Thanks guys
G
Guest
Diggerdude said:
Does a AI coil loose depth compared with a DD of same size?
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Not that I have noticed.
The main reason I said AI is because a gpx5000 is designed to be used with a mono. The only time I would use a DD would be on salt lakes and near power lines, hence the AI.
I have also jagged a few ironstone species with a DD that my mono missed.
DD
The main reason I said AI is because a gpx5000 is designed to be used with a mono. The only time I would use a DD would be on salt lakes and near power lines, hence the AI.
I have also jagged a few ironstone species with a DD that my mono missed.
DD
G
Guest
Why not a 14", 16", 18" or 20" + mono coil?condor22 said:
condor22
Mike
The main reason for the bigger DD is that considering the conical radiation pattern of the Mono, I thought that the more wedge bladed pattern of the DD would cover a patch with fewer passes and quicker than a Mono. If the patch then looks promising, I would then go over again with the 11" mono or the 18 x 12 elliptical I have.
Or, would I be wasting my time with a larger DD?
If so, given the list of coils I have (top of this thread) would something else be a better option.
BTW I do have a Minelab Pro Find, so I'm not looking at a pinpointer.
Or, would I be wasting my time with a larger DD?
If so, given the list of coils I have (top of this thread) would something else be a better option.
BTW I do have a Minelab Pro Find, so I'm not looking at a pinpointer.
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I reckon your wasting your money buying the DD for a patch finder, use the 18x12 you already have, thats what they are for.
DD
DD
condor22
Mike
Thanks, an honest answer and I'll take it on board.
peterau
Peter
Hi All, I am looking to try a larger coil on my 5000 to get away from just detecting heaps. I currently have a 6x8 NF, 11" mono and DD, 14 x 9 NF. I am looking to procure a larger mono coil. I also have a 2200 v2 with a 14" DD pro elite and a 18" DD coiltek . My questions are, would these large DD coils be worthwhile, suitable and effective for my purpose on my 5000, or would it be a compromise. Should I just get a large mono. Cheers peterau
Hi Peter,
The coils you have are fine for general detecting on a goldfield rather than on a heap.
A larger coil is usually used to locate a patch at depth. Mostly monos are used for that. Like coilteks UFO coil.
Having said that a lot of small subsurface gold has been found with large coils like the UFO.
DD's are great as well but you will lose a bit of depth, not much really, but you do get the benefit that they are quiter than a mono on highly mineralised ground.
The best all round mono in my limited experience is the 14" coiltek round solid. But you may also want to look at the newer Litz wire monos like the nugget finder range.
The smaller 6" monos are used to clean up a patch or where terrain like long grass is a problem. They are good for finding small gold close to the surface.
Hope it helps
The coils you have are fine for general detecting on a goldfield rather than on a heap.
A larger coil is usually used to locate a patch at depth. Mostly monos are used for that. Like coilteks UFO coil.
Having said that a lot of small subsurface gold has been found with large coils like the UFO.
DD's are great as well but you will lose a bit of depth, not much really, but you do get the benefit that they are quiter than a mono on highly mineralised ground.
The best all round mono in my limited experience is the 14" coiltek round solid. But you may also want to look at the newer Litz wire monos like the nugget finder range.
The smaller 6" monos are used to clean up a patch or where terrain like long grass is a problem. They are good for finding small gold close to the surface.
Hope it helps
condor22
Mike
I have the std 11" mono & DD with my 5000, also a 8" mono Minelab and an 18x12 Coiltek mono. I ummed and aahed about a bigger DD for trashy ground I wanted to cover a little quicker. (less overlap). I wasn't prepared to pay $390 to do that.
However, I was in Coiltek in Mayborough a couple of weeks ago and saw a Minelab Commander 15x12 DD second hand that had very little wear on it for $200 so I bit the bullet on that one and got it. It had apparently only seen beach use hence little wear, but the connector is a little discoloured from salt air.
It works well, when I use it in DD mode I have discriminate off, when I got a target, I turned discriminate on, if the target stayed sweet I dug, if not I walked on. I think in the first 2 hours I saved myself digging a doz and half holes.
However, I was in Coiltek in Mayborough a couple of weeks ago and saw a Minelab Commander 15x12 DD second hand that had very little wear on it for $200 so I bit the bullet on that one and got it. It had apparently only seen beach use hence little wear, but the connector is a little discoloured from salt air.
It works well, when I use it in DD mode I have discriminate off, when I got a target, I turned discriminate on, if the target stayed sweet I dug, if not I walked on. I think in the first 2 hours I saved myself digging a doz and half holes.
G
Guest
The 14" Nugger Finder coil is a quiet coil and light in weight as well.
peterau
Peter
Thanks for the replies. Depth wise would a dd 18 inch coil be equvilent to a14 or 16 inch mono cheers peterau
G
Guest
Good question.
The answer might be yes but you may miss the
Smaller gold the smaller mono is sensitive to
Compared the 18" dd.
Below is a coil selection pdf which might help.
http://www.minelab.com/__files/f/11792/KBA_02-1_Coil_Selection_Guide.pdf
The answer might be yes but you may miss the
Smaller gold the smaller mono is sensitive to
Compared the 18" dd.
Below is a coil selection pdf which might help.
http://www.minelab.com/__files/f/11792/KBA_02-1_Coil_Selection_Guide.pdf
Teemore
One foot out the door
Can't complain about recent success with the SDC or the 4800 with the 14x7 NF or the new 14" Mono Elite but have a couple of locations where the screaming of what I'm assuming is rusted metal is keeping me away (at least I hope it's just junk).
Been thinking of using a DD with Iron Reject but ...... I'm assuming with a trade off of some loss in depth .......
So just how much depth do I lose????
If using a 11"mono how much does loss is there if using a 11" DD (1", 3", 6" ???) or to put it another way how large a DD would be needed to get the same depth that a Mono would give (14", 18" ????).
If using say the Coiltek 14" Pro DD what depth equivalent in a mono coil would that be (11", 8" ???).
Hope those questions make some sense and more so that someone has some tech knowledge to provide a guide.
Cheers Tom.
Been thinking of using a DD with Iron Reject but ...... I'm assuming with a trade off of some loss in depth .......
So just how much depth do I lose????
If using a 11"mono how much does loss is there if using a 11" DD (1", 3", 6" ???) or to put it another way how large a DD would be needed to get the same depth that a Mono would give (14", 18" ????).
If using say the Coiltek 14" Pro DD what depth equivalent in a mono coil would that be (11", 8" ???).
Hope those questions make some sense and more so that someone has some tech knowledge to provide a guide.
Cheers Tom.
condor22
Mike
I'll stand corrected if wrong, but to my knowledge it's not a specific difference. In some grounds you may get deeper with a DD than a mono, i.e. in very noisy ground a DD may give a quieter response.
However, I have heard some say the rule of thumb is 1 coil size up on DD will give a similar depth.
However, I have heard some say the rule of thumb is 1 coil size up on DD will give a similar depth.
That seems to be a general rule of thumb.
11" mono = 14" DD
14" mono = 16-18" DD etc. etc.
By design the DD will be more stable in highly mineralised ground & can actually detect deeper than a mono. The disadvantage is less sensitivity to smaller gold & less depth in milder conditions than the equivalent sized mono. I have never seen any definitive testing on actual depth losses & have always just gone with the fact detector & coil manufacturers tell us you will lose some depth with a DD in all but the most highly mineralised ground.
DD's can also have an advantage in high EMI/interference areas.
Like Condor says though if the ground is iron infested or you aren't happy with how the mono is performing for you re: noise etc. then worrying about loss of depth is obsolete. If you can comfortably use a DD or find it's effectively blanking the majority of iron junk then it will be more advantageous than anything. Any loss of depth will be inconsequential.
11" mono = 14" DD
14" mono = 16-18" DD etc. etc.
By design the DD will be more stable in highly mineralised ground & can actually detect deeper than a mono. The disadvantage is less sensitivity to smaller gold & less depth in milder conditions than the equivalent sized mono. I have never seen any definitive testing on actual depth losses & have always just gone with the fact detector & coil manufacturers tell us you will lose some depth with a DD in all but the most highly mineralised ground.
DD's can also have an advantage in high EMI/interference areas.
Like Condor says though if the ground is iron infested or you aren't happy with how the mono is performing for you re: noise etc. then worrying about loss of depth is obsolete. If you can comfortably use a DD or find it's effectively blanking the majority of iron junk then it will be more advantageous than anything. Any loss of depth will be inconsequential.
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