DD coil in mono mode? = Confused

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Mick64

Michael Ortiz
Joined
Jul 25, 2016
Messages
122
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Location
Albury, NSW
Hi,
I've just purchase a good second hand 4500, I've taken it out once and tried a few different settings and picked up shot, bullet and alike so I must be doing something right.
My SDC picks up a 0.25gram at a depth of 3 inches with no problems, the 11"DD coil in DD mode doesn't.....however if I change it to mono, it picks it up easily

Why is this?

I then tried it on a 2 gram at 6 inches, the SDC no probs, the 11"inch DD on the 4500 yes it picked it up, but in mono it didn't?
 
Cant answer that one, but I have heard of people using a DD coil, and momentarily switching back to standard on the switch in aid of targeting, as the single mode offers a benifit that cant be done in DD mode! :/
 
You mean cancel or mono? I usually run my DD in mono. There are some highly experienced detectorists that run DD in mono and vice versa who will hopefully be able to shed some light on the matter.
 
nuggetino said:
You mean cancel or mono? I usually run my DD in mono. There are some highly experienced detectorists that run DD in mono and vice versa who will hopefully be able to shed some light on the matter.

Run the DD in Mono (not cancel) it just seems "sharper"

I also have the 14" Coiltek Elite which I run in Mono with no problems, just has me confused on the 11". I'm deciding on whether I should keep the SDC or the 4500 with some different coils. Every time I pull out the SDC I always get some sort of Gold, hoping I can pull some small nuggets with the 4500 too....just to make my decision harder :|
 
Mick64 said:
Hi,
I've just purchase a good second hand 4500, I've taken it out once and tried a few different settings and picked up shot, bullet and alike so I must be doing something right.
My SDC picks up a 0.25gram at a depth of 3 inches with no problems, the 11"DD coil in DD mode doesn't.....however if I change it to mono, it picks it up easily

Why is this?

I then tried it on a 2 gram at 6 inches, the SDC no probs, the 11"inch DD on the 4500 yes it picked it up, but in mono it didn't?
When you put your DD in mono you are effectively cutting the coil in half into D shaped pseudo mono
 
The SDC and 4500 complement each other. They find different gold although there's a crossover where some gold can be found with either one. The SDC is usually better on small surface gold and the 4500 is better on bigger deeper gold. You can get by with either detector but both will leave quite a bit behind depending what is on that patch.

I've never used the DD coil much so I can't answer that question but why wouldn't you just use the 11" Mono unless you need the features of a DD?
 
Moneybox said:
The SDC and 4500 complement each other. They find different gold although there's a crossover where some gold can be found with either one. The SDC is usually better on small surface gold and the 4500 is better on bigger deeper gold. You can get by with either detector but both will leave quite a bit behind depending what is on that patch.

I've never used the DD coil much so I can't answer that question but why wouldn't you just use the 11" Mono unless you need the features of a DD?

Thanks Moneybox, I'll see how the hunt goes this weekend in the Triangle
 
Hi Mick, I've heard using a DD in mono cuts the coil in half like Madtuna said and also heard it makes that half more sensitive to small gold which might be why it picked up the .25g and not the 2g?
I'd also heard of people flicking to mono with a DD when they detect a mullock heap which makes sense to the above comment.
 
If you run the DD in mono it's like turning it into a 7" mono, so it's more sensitive but loses depth, the pin point will be off centre also.

Unless you have a reason to run the dd like discrimination the standard 11" mono is a much better coil if it came with that.
It will find that .25 easily and punch a lot deeper than the sdc.
 
ProspectorPete said:
Hi Mick, I've heard using a DD in mono cuts the coil in half like Madtuna said and also heard it makes that half more sensitive to small gold which might be why it picked up the .25g and not the 2g?
I'd also heard of people flicking to mono with a DD when they detect a mullock heap which makes sense to the above comment.

Hi Ya Pete,

yes it does make sense now....I recognise that little nugget on your coil too ;)

I'm heading into the Triangle tomorrow (Friday) and Saturday to give the SDC and 4500 a go, mainly shallow areas but there's a couple of deeper spots I'll run the 4500 in. I'll be heading back out towards end of April early May, I'll let you know the dates if your available
 
Jarrod84 said:
If you run the DD in mono it's like turning it into a 7" mono, so it's more sensitive but loses depth, the pin point will be off centre also.

Unless you have a reason to run the dd like discrimination the standard 11" mono is a much better coil if it came with that.
It will find that .25 easily and punch a lot deeper than the sdc.

Hi Jarrod, unfortunately I don't have the 11" mono so I'll have to invest in a smaller one I think. In saying that the 14" coiltek also picked up the little 0.25 at 2", but lost it after that depth, the 2.0 gram it picked up at 10" with no problems.

I'll keep my eye now for a smaller coil :)

Mick
 
Mick64 said:
ProspectorPete said:
Hi Mick, I've heard using a DD in mono cuts the coil in half like Madtuna said and also heard it makes that half more sensitive to small gold which might be why it picked up the .25g and not the 2g?
I'd also heard of people flicking to mono with a DD when they detect a mullock heap which makes sense to the above comment.

Hi Ya Pete,

yes it does make sense now....I recognise that little nugget on your coil too ;)

I'm heading into the Triangle tomorrow (Friday) and Saturday to give the SDC and 4500 a go, mainly shallow areas but there's a couple of deeper spots I'll run the 4500 in. I'll be heading back out towards end of April early May, I'll let you know the dates if your available
Definitely keen to catch up again mate and great to see you get the 4500 too, you've got a great choice there for covering varied ground.
 
Perfectly explained in the user manual. Page 45
https://www.minelab.com/__files/f/3965/4901-0063-1.1 Instruction Manual GPX-4500_screen.pdf

1521109553_coil_rx.jpg


If you look at that diagram, it's the DD position that is only using half the coil. One side to transmit, and one side to receive. In Mono mode, transmit is also on the left winding, but it receives off both windings.

11" DD coil in Mono, think of it as having performance characteristics somewhere between an 11" DD and 11" mono.

- More Sensitive than a DD
- Less depth than an 11" round Mono
- Better ground handling compared to an 11" mono
- Not as quiet as DD mode
- Better EMI suppression compared to 11" mono
- MAY, in the right ground be able to use Sens Extra where you MAY struggle with a straight mono

The other way you could look at it would be to compare to an 8" mono. The 11" DD in Mono is essentially an 11x7" elliptical, so the 8" mono will provider a sharper response on most small gold, but the 11" would be superior in ground handling.
 
PhaseTech said:
- More Sensitive than a DD
- Less depth than an 11" round Mono
- Better ground handling compared to an 11" mono
- Not as quiet as DD mode
- Better EMI suppression compared to 11" mono
- MAY, in the right ground be able to use Sens Extra where you MAY struggle with a straight mono

The other way you could look at it would be to compare to an 8" mono. The 11" DD in Mono is essentially an 11x7" elliptical, so the 8" mono will provider a sharper response on most small gold, but the 11" would be superior in ground handling.

Thanks Nenad, now it starts to make sense. I'll download the manual and have a read through it tonight out in the bush.

Appreciated
Mick
 
Mick64 said:
nuggetino said:
You mean cancel or mono? I usually run my DD in mono. There are some highly experienced detectorists that run DD in mono and vice versa who will hopefully be able to shed some light on the matter.

Run the DD in Mono (not cancel) it just seems "sharper"

I also have the 14" Coiltek Elite which I run in Mono with no problems, just has me confused on the 11". I'm deciding on whether I should keep the SDC or the 4500 with some different coils. Every time I pull out the SDC I always get some sort of Gold, hoping I can pull some small nuggets with the 4500 too....just to make my decision harder :|

Mick I have used the 4500 since its release date. I have a 7000 also but will always keep the 4500. It is deadly on deep gold and has paid itself off 39 times.

Looking at your deliberations above ....I would encourage you to persist with the 4500 using only mono coils. I would go for a round 12 or 14 mono coil and get a sadie 8" coil or similar for small gold.

The 4500 has the ability to cover ground and find deep gold the SDC will miss...and the SDC is not the detector you want for searching large areas. It has its place but not as an all round detector.

Over time the 4500 will deliver in all ground types and give you more gold. If you use an SDC you may come home with some tiddlers on a daily basis but it will not keep up with 4500 unless there is only tiny ground present. With a 4500 you give yourself the chance to get a hefty slug at depth, missed by others.

Cheers RDD

PS to confuse things...always use the DD mode rather then mono when using mono coils. Folklore says the machine will run very slightly more stable compared to mono...although I have found it is impossible to tell if there is any real difference.
 
RedDirtDigger said:
Mick64 said:
nuggetino said:
You mean cancel or mono? I usually run my DD in mono. There are some highly experienced detectorists that run DD in mono and vice versa who will hopefully be able to shed some light on the matter.

Run the DD in Mono (not cancel) it just seems "sharper"

I also have the 14" Coiltek Elite which I run in Mono with no problems, just has me confused on the 11". I'm deciding on whether I should keep the SDC or the 4500 with some different coils. Every time I pull out the SDC I always get some sort of Gold, hoping I can pull some small nuggets with the 4500 too....just to make my decision harder :|

Mick I have used the 4500 since its release date. I have a 7000 also but will always keep the 4500. It is deadly on deep gold and has paid itself off 39 times.

Looking at your deliberations above ....I would encourage you to persist with the 4500 using only mono coils. I would go for a round 12 or 14 mono coil and get a sadie 8" coil or similar for small gold.

The 4500 has the ability to cover ground and find deep gold the SDC will miss...and the SDC is not the detector you want for searching large areas. It has its place but not as an all round detector.

Over time the 4500 will deliver in all ground types and give you more gold. If you use an SDC you may come home with some tiddlers on a daily basis but it will not keep up with 4500 unless there is only tiny ground present. With a 4500 you give yourself the chance to get a hefty slug at depth, missed by others.

Cheers RDD

PS to confuse things...always use the DD mode rather then mono when using mono coils. Folklore says the machine will run very slightly more stable compared to mono...although I have found it is impossible to tell if there is any real difference.

Thank you for your valuable input, after this weekend I do like using the 4500, however I will have to invest in some coils if I am to keep it. I ran into a guy who swears by the 12" nugget finder, then again the other gut I ran into only uses the 14" Coiltek (which I have). I haven't checked out the Sadie...If I can get close to the SDC by using different coils, I'd be a happy camper.

Mick
 
I have been using the 11dd recently in high trash area iron descrim at 5, It has saved me digging a lot of trash but I still find I am digging small bits of trash that are not being descriminated due to the small signals I also note that this is not as sensitive and will not pick up the small bird shot the 15*12 mono will.
The 11dd run in mono will pick the bird shot but not deeper than 2 and then only just, I find the 15*12 better on small targets at depth where the 11dd does have its place I prefer using the 15*12 the down side is the weight and size around tight spots, I admit Im no pro and havent found a many nuggets but thats what I found so far, for smalle gold I will look at getting a smalle mono like the new 9 elite
 
madtuna said:
Mick64 said:
Hi,
I've just purchase a good second hand 4500, I've taken it out once and tried a few different settings and picked up shot, bullet and alike so I must be doing something right.
My SDC picks up a 0.25gram at a depth of 3 inches with no problems, the 11"DD coil in DD mode doesn't.....however if I change it to mono, it picks it up easily

Why is this?

I then tried it on a 2 gram at 6 inches, the SDC no probs, the 11"inch DD on the 4500 yes it picked it up, but in mono it didn't?
When you put your DD in mono you are effectively cutting the coil in half into D shaped pseudo mono
Does that mean you are halving the coil size by doing that ? Maybe thats why it becomes more sensitive.
 

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