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#26

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
14 November 2018 10:44 am

On very large Items the TDI's can see things that can be measured in metres but on small Coins and Nuggets they really suffer, where even a good VLF will wipe their clock, In very hot got the TDI's will be the Victor over a VLF but in any thing less the out come is reversed.


Dig em all,

#27

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
14 November 2018 03:13 pm

Simple thing to try first would be (as already suggested) try a small coil like a Nugget Finder Sadie 8"×6" mono, Coiltek 6" coil etc. Here's a thread on several small coils being tested on the Whites TDI Oz Pro : https://www.prospectingaustralia.com.au … p?id=21209
The Nugget Finder Sadie is a standout IMO.

dear thank you too match for your helping ..

but i have one one qu and the answer will help me too match ..

did any one try to test self made dd serch coil in tdi or spp ? if yes i want try to start make it if i find the link for its information that time i will be ready to
make comparing between dod and dd and mono

also if we try dd serch coil and its working with out needing to change any jumper or ctc.. its good for as to improve dirctly to dod serch coil which i have
now all informatio about it.

rgds

1 user likes this post: Ship of fools

#28

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
14 November 2018 09:28 pm

pcs spp white

1542190962_spp_tdi_2.jpg

if look in down board you find jumper . now its workin no 3 and 4 together .

1542191255_super_d.jpg
1542191255_viber_image.jpg

#29

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
14 November 2018 09:38 pm

so by this information up beside your more information we hop to succes to do some things

rgds

#30

Ship of fools
Member
From: Mackay, QLD
Joined: 04 March 2018
Posts: 292
Member
14 November 2018 10:20 pm

Moatazfaize I admire your work. I look forward to see your results.
Will the centre coil be tx or rx? A hard decision no doubt. I believe the gpz 7000 alternates.
What and how are you going to shield with? I would think each coil needs to be shielded seperate?
Matt T


Though I could not caution all, I still might warn a few;
Don't lend your hand to raise no flag atop a Ship Of Fools.

#31

Ship of fools
Member
From: Mackay, QLD
Joined: 04 March 2018
Posts: 292
Member
14 November 2018 10:28 pm

Moatazfaize wrote:

Simple thing to try first would be (as already suggested) try a small coil like a Nugget Finder Sadie 8"×6" mono, Coiltek 6" coil etc. Here's a thread on several small coils being tested on the Whites TDI Oz Pro : https://www.prospectingaustralia.com.au … p?id=21209
The Nugget Finder Sadie is a standout IMO.

dear thank you too match for your helping ..

but i have one one qu and the answer will help me too match ..

did any one try to test self made dd serch coil in tdi or spp ? if yes i want try to start make it if i find the link for its information that time i will be ready to
make comparing between dod and dd and mono

also if we try dd serch coil and its working with out needing to change any jumper or ctc.. its good for as to improve dirctly to dod serch coil which i have
now all informatio about it.

rgds

I have only ever been able to try one DD coil an 11inch commander and I hope it was broken before I plugged it in, as it was when I tried it! It would only give a signal in the 75mm centre of the coil and did the same when I put it on the Gpx, I hadn’t tried it before that.
Matt T

Last edited by Ship of fools (14 November 2018 10:34 pm)


Though I could not caution all, I still might warn a few;
Don't lend your hand to raise no flag atop a Ship Of Fools.

#32

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
15 November 2018 04:05 am

Moatazfaize wrote:

Simple thing to try first would be (as already suggested) try a small coil like a Nugget Finder Sadie 8"×6" mono, Coiltek 6" coil etc. Here's a thread on several small coils being tested on the Whites TDI Oz Pro : https://www.prospectingaustralia.com.au … p?id=21209
The Nugget Finder Sadie is a standout IMO.

dear thank you too match for your helping ..

but i have one one qu and the answer will help me too match ..

did any one try to test self made dd serch coil in tdi or spp ? if yes i want try to start make it if i find the link for its information that time i will be ready to
make comparing between dod and dd and mono

also if we try dd serch coil and its working with out needing to change any jumper or ctc.. its good for as to improve dirctly to dod serch coil which i have
now all informatio about it.

rgds

YES People have tried DD coils on the TDI's and only very few of them work on the TDI's,

It is not the Coil that makes the 7000 so good it is the person who wrote the software, the Coil is just an Arial an using a DD on a TDI is useless 85% of the time.


Dig em all,

#33

steelPHASE
Member
From: Ocean Grove
Joined: 03 September 2018
Posts: 36
Member
15 November 2018 06:49 am

Ridge Runner wrote:

YES People have tried DD coils on the TDI's and only very few of them work on the TDI's,

It is not the Coil that makes the 7000 so good it is the person who wrote the software, the Coil is just an Arial an using a DD on a TDI is useless 85% of the time.

Agree totally but it looks like some are not prepared to listen.

The GPZ7000 uses a center TX coil with 2 outer RX coils. The DOD coil uses the receive coils to effectively cancel out GF and EMI. Unless the RX circuit is designed to do this, a DOD coil will be a lot less efficient than a simple mono or standard coil.

The DOD coil also will also have to be 'nulled' which calls for precise location of the outer coils with regard to each other and the inner coil.

The timings to run a DOD coil are totally different to those needed to run a mono or standard DD coil. Unless you have access to the software that controls everything and are able to re-program the Whites, I doubt very much you will be able to have a good working unit using this coil.


Manufacturers of the sP01 Enhancer as well as other high quality prospecting accessories

2 users like this post: Ridge Runner, Skip

#34

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
15 November 2018 07:22 am

steelPHASE wrote:
Ridge Runner wrote:

YES People have tried DD coils on the TDI's and only very few of them work on the TDI's,

It is not the Coil that makes the 7000 so good it is the person who wrote the software, the Coil is just an Arial an using a DD on a TDI is useless 85% of the time.

Agree totally but it looks like some are not prepared to listen.

The GPZ7000 uses a center TX coil with 2 outer RX coils. The DOD coil uses the receive coils to effectively cancel out GF and EMI. Unless the RX circuit is designed to do this, a DOD coil will be a lot less efficient than a simple mono or standard coil.

The DOD coil also will also have to be 'nulled' which calls for precise location of the outer coils with regard to each other and the inner coil.

The timings to run a DOD coil are totally different to those needed to run a mono or standard DD coil. Unless you have access to the software that controls everything and are able to re-program the Whites, I doubt very much you will be able to have a good working unit using this coil.

It does seem crazy to try and use the 7000 type coil because the 7000 is more like a Hybrid VLF as opposed to a PI, If it was that easy we would all be using VLF coils on our PI machines because they are so much hotter on fine gold.

Whites put in years in to making the TDI's yet there is always some one who thinks they know better, If it worked well with a DD or a DOD Coil then Whites would have made one for it, Or at leased Hired him as their Technical Advisor. thumbsdown


Dig em all,

2 users like this post: grubstake, mond

#35

Ship of fools
Member
From: Mackay, QLD
Joined: 04 March 2018
Posts: 292
Member
15 November 2018 08:35 pm

I’m very disappointed this guy is having a go! You guys are pissing on his parade!
If people didn’t have a go then we wouldn’t have Litz wire, no flat wound coils no gpx’s or Gpz’s or Qed’s!
For that matter no Spo1’s.
Encouragement is due!
Matt T


Though I could not caution all, I still might warn a few;
Don't lend your hand to raise no flag atop a Ship Of Fools.

3 users like this post: Dan79, Skip, Caconym

#36

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
15 November 2018 09:03 pm

Ship of fools wrote:

I’m very disappointed this guy is having a go! You guys are pissing on his parade!
If people didn’t have a go then we wouldn’t have Litz wire, no flat wound coils no gpx’s or Gpz’s or Qed’s!
For that matter no Spo1’s.
Encouragement is due!
Matt T

It's not a case of Peeing on any ones parade, We have been over this many times on this forum and other forums, The GPZ is a very complex machine unlike any other on the market, and we are just trying to save him any expense or disappointment or Both, And seeing as I own a TDI SL and Owned the TDI pro I know for a fact that DD's "Do Not" work well on the TDI's, there are only about 3 or 4 DD's that sort of work on the TDI and the GPZ Coil Is Not One Of Them,

And to get them to sort of work you have to off set the Delay or Ground Balance, which moves the Target ID Range and in some cases cause you to reduce the Gain setting.

As a TDI Owner don't you think that I would want them to work ? but sad to say they do not So I am stuck using Mono's or Duel Field Mono's.

Last edited by Ridge Runner (15 November 2018 09:24 pm)


Dig em all,

1 user likes this post: Ship of fools

#37

steelPHASE
Member
From: Ocean Grove
Joined: 03 September 2018
Posts: 36
Member
16 November 2018 07:00 am

Ship of fools wrote:

I’m very disappointed this guy is having a go! You guys are pissing on his parade!
If people didn’t have a go then we wouldn’t have Litz wire, no flat wound coils no gpx’s or Gpz’s or Qed’s!
For that matter no Spo1’s.
Encouragement is due!
Matt T

Not true. All the things you have quoted are re-designs of an existing idea. Not trying to add on to an existing design. Two totally different concepts.

I love seeing people experiment and try things but I just hate to see him waste his time and perhaps damage his machine in the process. To be honest I think time would be better spent buying the MPP detector kit and modifying this. It could possibly lend itself to redesign to run with a dod coil. You can add a microprocessor to the design and alter all the timings etc.

But back to the topic- get a factory built mono coil (even if you have to borrow it) and then check that the detector is actually working properly to start with.


Manufacturers of the sP01 Enhancer as well as other high quality prospecting accessories

#38

nesral
Member
Joined: 05 January 2015
Posts: 198
Member
16 November 2018 08:25 am

Good on Moatazfaize for having a go at coil making.

The made for TDI DD coils I'm using work extremely well and are my preferred coils for difficult ground and small low conducting targets.

Coilteck and Minelab DD coils also work well on my TDI and SPP.

Dual field coil on the TDI BH is an excellent match when beach hunting, Whites got that one right!

#39

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
17 November 2018 01:38 am

Dear

If Dd coil working in tdi or spp that means rx and tx in pcb board
are accept working with DoD search cable. That for DoD cable has two
Rx cable same as one .

I am going to make DoD search cable same as 2 point

1- same one tx and rx mono spider cable in same time.
2-or same as dd coil as we have 2 rx and one tx

The the both two rx cables Must be 2 ohm and 300 micro Henry
And the tx also same information .

I will work total diameter 12

Plz if any help information I need it .

Rgds

#40

grubstake
Member
From: Perth, WA
Joined: 20 October 2014
Posts: 1,662
Member
17 November 2018 09:56 am

Moatazfaize wrote:

Plz if any help information I need it .

I'd suggest you look through all the posts in the Findmall Whites TDI Classroom while it's still available:
https://www.findmall.com/list.php?73


Where it is, there it is.

1 user likes this post: mbasko

#41

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
19 November 2018 03:06 pm

Plz look to this design all this down pic we xan do it as mono coils

1542600310_screenshot_------1.jpg
1542600310_--_...jpg
1542600311_post-6747-1246826783.jpg

If we can do good things ,, plz any update for helping , I need your
Feed back .

Rgds

Last edited by Moatazfaize (19 November 2018 03:08 pm)

#42

steelPHASE
Member
From: Ocean Grove
Joined: 03 September 2018
Posts: 36
Member
19 November 2018 05:27 pm

I have built the middle design (spider wound) and its a very good mono coil. The design reduces the capacitance which makes it very fast. If you wind it with Litz wire you will have the best outcome.
Also make sure you shield it well.

This article is very good and will help you understand coil design.
http://www.geotech1.com/pages/metdet/pr … stCoil.pdf

Last edited by steelPHASE (19 November 2018 05:29 pm)


Manufacturers of the sP01 Enhancer as well as other high quality prospecting accessories

#43

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
03 December 2018 12:04 am

this from memeber (reg)

There has been some confusion about using DD coil on The TDI series of detectors. In fact, someone from OZ mentioned to Miner John that Eric Foster indicated that DD coils wouldn't work on the TDI units. To the best of my knowledge, Eric never said that. What he might have said is that DD coils weren't necessary and the TDI would work find in most areas with a mono coil. Many years ago, Eric mentioned DD coils would probably be necessary in OZ, but this was stated well before he designed the GS 5 (the TDI initial design).

DD coils will work fine on any TDI including the SPP units. DD coils may work a little better on the TDI Pro simply because of the filtering modification on the Pro which allows for a little faster sweep speed.

The regular TDI and the SL series have a little slower filtering, thus requiring slower sweep action for best results and maximum depth. This is especially true when searching for small gold. So, regardless of the coil used, the SL series clearly does require a slower sweep speed for the best results.

Since the typical overlap of a DD is quite narrow, the detection range is nowhere near as wide as that found on a mono coil, thus the signal has more time to increase on a mono and this longer time of detection makes it easier to hear. Different designs of a DD could be tried including the rather odd design of the ATX DD coil which appears to have a small round overlap area.

DD coils are popular on VLF units because the reduce the ground signal. This is also true on a PI but also isolate the transmit from the receive on a PI, thus reducing noise further.

DD coils also have a narrow detection range which is quite sensitive, thus making them preferred on some areas when looking for small gold. However, keeping the DD coil low and going slow are required for proper results.

White's developed the Dual Field (DF) as a means of using a mono instead of a DD coil. Dan Geyer was the engineer responsible for the design. Unfortunately, Eric Foster found that the DF had some limitations in OZ and were not recommended for use there. Since the DF coil design was patented by White's, some other idea had to be implemented if the same concept was to be used that would allow a mono coil to have an enhanced small gold response.

Thus, the folded or foldback design was developed by me many years ago. The idea was to enhance signals from small gold without the use of a DF or a DD design. The specifics can be found back around 2009 on the Geotech forum where I posted how to build one. The idea was to build a figure 8 coil but fold the top part of the 8 back into the bottom half and then elongate the inner portion of the winding. The result was an increased field that enhanced small gold but didn't suffer some of the ground problems of the DF. Here is the link to that idea

http://www.geotech1.com/forums/showthre … olded+coil

Drop down to my post about a different dual field design.

So, now you know a little more about the history of DF and the folded mono design.

Reg

#45

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
03 December 2018 07:00 am

Moatazfaize wrote:

DD coils are popular on VLF units because the reduce the ground signal. This is also true on a PI but also isolate the transmit from the receive on a PI, thus reducing noise further.

DD coils also have a narrow detection range which is quite sensitive, thus making them preferred on some areas when looking for small gold. However, keeping the DD coil low and going slow are required for proper results.

Fact is a DD on a VLF makes the detector suffer a bit more from EMI, And also a Concentric on a VLF is a lot Hotter on small Gold than a DD and the Concentric is normally deeper, As is a Mono on a PI machine,


Dig em all,

#46

Skip
Member
Joined: 02 October 2018
Posts: 112
Member
03 December 2018 11:47 am

Well hats off to all. I don't know shite about coils so its been a good read for me.

Just sayin tongue


The great out doors.. this is livin

1 user likes this post: Ded Driver

#47

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
03 December 2018 09:44 pm

last i find the sulusion

my idea to build folder mono coil 5>9 like reg search coil

may this solve this issues

rgds

1 user likes this post: Ridge Runner

#48

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
03 December 2018 10:50 pm

Moatazfaize wrote:

last i find the sulusion

my idea to build folder mono coil 5>9 like reg search coil

may this solve this issues

rgds

That's a good Idea because they work really well on the TDI's thumbsup


Dig em all,

#49

Moatazfaize
Member
Joined: 31 October 2018
Posts: 21
Member
05 December 2018 03:50 pm

this from mr reg who itink desgner folded mono :_

The dual field design coil was primarily developed to provide decent depth on large objects plus enhanced sensitivity to small gold. The design which was patented by the late Dan Geyer while he worked for Whites and works very well for this purpose.

Now, with that said, the dual field (DF) doesn't have quite the depth of a similar size mono plus it is more temperamental in bad ground making it more difficult to ground balance. That is why TDI's sent to OZ are sent with a mono coil.

Fortunately, in most places here in the US the DF ground balances well enough to work satisfactorily, but still may display a slight inability to GB as well as a similar size mono. In OZ, the inability to GB was very noticeable, thus the Mono coil was/is the coil generally preferred.

The foldback (FB) design was developed in 2009 as an alternative to the DF coil which meant it had enhanced sensitivity to small gold because of the foldback part and great depth because of the main coil size. Since the DF is patented, then duplicating would be a violation of White's patent, so something different had to be developed for those wanting similar features but not in violation of the White's patent.

Unfortunately, the design is such that it is tough to make a 12" FB design that works at the minimum delay. Instead, it sort of mimics a mono size if the foldback part was not folded back.

The idea of a FB is to create a larger mono, pinch it into a lopsided figure 8 with the top part much smaller than the bottom part of the 8. Then the top part is twisted a half turn and folded back into the lower portion. Finally, the smaller part is sort of pinched into a narrow elliptical inside the larger portion. This smaller elliptical enhances the small gold signals while the larger coil provides the depth on larger objects.

Here is a link to the post where I discussed the design.

http://www.geotech1.com/forums/showthre … =fold+back

If you are interested in more information you can go to the link and learn more about its development. Drop down to my 7-3-09 post here I discuss the concept and reason for the design.

Now, what I found was the FB design has great depth plus enhances small gold signals also. The difference is the Foldback design doesn't have any of the negative GB problems while usually having greater depth when comparing similar size and shape coils.

A FB coil seemed to have a slight edge over a similar size and shape plain mono also.

You mentioned your use would be for relic hunting and if that is the case and you won't be hunting small gold then the DF or FB may not be the best choice. The exception would be if you have a need to find tiny pieces of metal. If that is not the case, the DF or even the Foldback may not be the best choice. Chasing small bits of metal when they are not the main desired target can be a real pain.

A simple mono might be cheaper and work better since it will do a better job of ignoring some of the real tiny stuff that might be detected with either the DF or the FB design.

Reg

#50

Ridge Runner
Member
Joined: 04 September 2014
Posts: 4,696
Member
05 December 2018 04:38 pm

I know the Folded mono is good for prospecting on the TDI's, And I would not use the standard DF for prospecting because I know it is not very sensitive to small nuggets because even air testing small bits of lead it struggles to see bits weighing 0.17grams, Most PI's will only see bits of that size within a couple of inches deep so even in hot ground a person would be better off using a VLF because if you are chasing Gold that size they are not going to be that deep no matter what type of machine you use.

Another annoying thing about the TDI SL and SPP is the slower sweep speed compared to the TDI Pro, Yes a person should take there time when prospecting but the SL and the SPP are just a bit too slow, Which is why when I am searching for small surface targets I prefer a VLF and they also ID junk,

One thing for sure, IF any of the TDI's are searching for Large Metals they will find it regardless of whether it is ground balanced or not, On larger Items the 12" DF will and can see them down to depths that can be measured in metres not feet, When it comes to large items the TDI SL is quite Brutal when it comes to depth and sometimes I think it is just Wired wrong because it has the power but it has it at the wrong time. I know of someone who found a piece of Iron the size of a 2 litre coke bottle at over 4 feet deep with the 12 DF on the TDI SL and I have found targets much deeper using the same set up.


Dig em all,


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