DD coil information and questions

[user 794]

Hi guys
My wife and I are to do a 14 week trip with 5 other vehicles through SA, NT and WA. Only my wife and I will spend a couple of days in Marble Bar and also a week in Kalgoorlie to do a bit of detecting.
I am more likely to use vacant land than the S40E route due to our being on the road so much and first trip 4wding over that way. I am learning Tengraph to do this properly.

Anyway, it's been suggested to me that I will need a big DD coil over there. I have the 11" DD for the 5000 and apart from other mono coils I have a 17x11NF. I've spoken to other people (all eastern staters so far) and they reckon that a mono is fine with the 5000 over there.
What do you reckon? Do I need a 17x11" Coiltek DD, an 18" coiltek DD or not any DD at all?

ta

 

[Diggerdude]

I have a 17x11 DD mate and have never needed to use it over here, I always use monos. If you decide you still want one I have a brand new one collecting dust I can do you a deal on.

DD

 

[WalnLiz]

Run all over WA and only run Monos.' Only ever ran a DD on one of the extreme salt lakes. I certainly wouldn't go out of my way to buy one especially if you already have the 11" DD which comes with the machine these days.

Cheers Wal.

 

[user 794]

Thanks guys

DD - I just mentioned in my response on the new members page that I may send you a PM once I suss out more info.

 

[Rodstar]

Hello all

I have a quick question about this coil, its listed on EBay and through bendigo gold feedback is 100% positive. so its all good there, its second hand they are asking $170 for it....
I have a GP3500 with the standard original coil on it, how much difference will a 14" coil make compared to the original one? is it just for seeking gold or can i use it with great success looking for coins too? is $170 a realistic price? is this the next coil i should get to arm my detector with or is there a more better suited one? I am still a novice with the detector and am still getting used to the beep boop burp noises but will get there!

Rod

 

[Guest]

As far as price that seems ok - $375 new (Coiltek 14" DD Pro Elite). It looks in good shape too.

 

[Rodstar]

is there much difference between the two? would it be better to spend the extra $$ for the elite?

 

[loamer]

I assume the standard coil you are now using is an 11" DD?

Here is a very general guide to the coils you are looking at. 11" vs 14"

small shallow nuggets - 11
large deeper nuggets - 14
highly mineralised - both
open ground (patch hunting for example) - 14
heavy scrub - 11

Yes, you will get better depth with the 14" but it depends on what you want and where you are. For example in scrubby country, the 14 will be pushing above the ground level and therefore depth can be lost. An example is the whipstick places around vic - you spend half the time battling trees and a big coil is not warranted - can't get it close to the ground whereas an 11 is fine. Visa versa on open ground - the 14 gives you a better coverage. You can get a lot of coverage and over a 10 hour or so day this adds up.

As for noises, the 3500 is a beaut detector and if well GB'd should be quiet on mineralised ground - yes it will warble on hot rocks and pockets of mineralised soil but those sounds, with experience, will eventually be discounted. One of my mates swears by the 3500 and has a selection of coils. Because of where we generally go (patch hunting) he sticks with the 14" but hits mullock heaps etc with the 11.

So there you go - if you can afford it, I would probably get it as its another tool. When you get a patch and want to do a clean out, its best to have a variety of coils. I checked the site as well - it looks good and the dealer seems OK.

 

[Guest]

The elite is slightly lighter but some people prefer the terracotta coils. Matter of opinion I guess. I've only used the elite so someone else may be able to help with a comparison?
I've only found buttons & buckles with it so far so it works for relic hunting :lol:
I am also, after some advice, looking at getting a 10 x 5 DD for hunting smaller gold.

 

[loamer]

The elite is slightly lighter but some people prefer the terracotta coils. Matter of opinion I guess. I've only used the elite so someone else may be able to help with a comparison?
I've only found buttons & buckles with it so far so it works for relic hunting :lol:
I am also, after some advice, looking at getting a 10 x 5 DD for hunting smaller gold.

mbasko - sorry to steal the thread but noted you run a 2200. I used to as well and the 10 x 5 is a beaut coil on mulllock heaps and really tight mongrel scrub/rocky country. I used to carry it in a day-pack for that very reason and switch over as required. Do some tests between shallow and deep settings - you might be surprised with the results. I found on some mullock heaps shallow setting could have a slightly different noise in the threashold.

 

[Rodstar]

Thanks Loamer and Mbasko, your invaluable knowledge is appreciated, i will go ahead and get it.
Yes my standard coil is the 11" DD

Cheers
Rod

 

[Guest]

mbasko - sorry to steal the thread but noted you run a 2200. I used to as well and the 10 x 5 is a beaut coil on mulllock heaps and really tight mongrel scrub/rocky country. I used to carry it in a day-pack for that very reason and switch over as required. Do some tests between shallow and deep settings - you might be surprised with the results. I found on some mullock heaps shallow setting could have a slightly different noise in the threashold.

Thanks once again Loamer - as always your advice is much appreciated. Was actually out with another forum member (lbg dreamer) who suggested trying one & can definitely see the benefits in his & your advice especially around this area. The old SD's away for a once over at Minelab at the moment (hope this laying off of 40 employees doesn't affect turnaround) so will be looking into it for my next trip out.

Mbasko, your invaluable knowledge is appreciated

Thanks :lol: but I'm just another hairy bummed rooster bumbling about in the bush trying to pick up some of the elusive yellow stuff too mate. Try to help where I can but there are many more knowledgeable people on here.

 

[nuggetino]

Have been thinking seriously about adding one of these to my arsenal as they do pop up used every so often. Just wondering if anyone else swings this monster when they're out detecting and what they think of it? I realize the coil is now discontinued so I assume not overly popular with the masses. cheers

 

[loamer]

Monos have pretty well limited the production of DD series. Don't know what you are running - I run a 24" DD on a 2200D at times. Very good but highly prone to picking up anything metal - your pick if not slung properly, belts etc. If you use one, go clean fatigue - no metal (apart from the pick slung over your shoulder.) Even when checking targets if you have a metal zipper and bending near the coil you can get a threashold noise. having said, fantastic for depth on crappy mineralised ground. gets heavy so you may want to rig up a bungy or something similar. best for patch hunting on fairly even ground or if i get a suspect noise off an 18" coil for example, I fit this bad boy and give it a run. The DDs still have there place. Seen this setup on the 2200 perform very well in testing against my 4500 and a 5000. If I am doing a slope, I sling it over my shoulder, go to the top and detect down hill. As said, they can get heavy. Good for the arsenal as you say. Excellent for known deep gold on highly trashy ground. Reason I run it on my 2200? Because I love my 2200 and I fairly well know its little blip, farts and wheezes. Oh yes - big user of battery power.

 

[nuggetino]

Thanks for a very intuitive answer loamer that's a better insight than i could have hoped for on the 24" dd coil. I also plan to get a large mono coil later for less mineralised ground. I'd be running the DD on the gpx4500 which i know isn't ideal but it's my only detector so I'll just have to make do with it.

 

[loamer]

Nuggetino - I too run a DD on my 4500. I carry an 11" DD in my daypack and switch too it if I hit a particularly nasty bit of ground (mineralisation) or find a trashy area. I sometimes run the 4500 with a DD and iron reject on and deliberately hit trashed areas - a bit of fun in areas the monos just scream and scream. DDs on the 4500 are still very good coils. Like you say about the 'arsenal' its good to have a weapon of choice. I think the 4500 with a 24" is fine - I just get sentimental about giving the 2200 a run every now and then. You are quite right about saying they are not being made - I really think you need to get them now. I even got an extra 14" DD, just in case (the 14" is THE coil fro a 2200 IMO). Coiltek are good coils too by the way.
2200 - useless with a mono on bad ground but a killer with the DD.
4500 - fantastic with a mono (biggest I run at the moment is a 12" round NF). Very good with a DD.

 

[nuggetino]

That's good to hear the big DD's still work ok on the GPX4500. My intentions are to have all bases covered in the event I find a patch. My confidence in the mono coils isn't high mainly because I haven't learned how to deal with all the hot rocks,emi and mineralization. If the GPX only worked with mono coils I'm sure I'd have been forced to learn these coils much sooner. Managed to snap up a 24" dd on ebay last night. Pretty excited to test it out after xmas. Will take your advice on going full body condom to avoid threshold noise

 

[loamer]

The monos and noise, its an old problem but getting better with the 4500/5000 series. I think you may have to test and play with the settings. If things get too noisy I run my 4500 on quiet and then also play around with the gain and stabiliser, I usually try and keep them + or - 2 from each other. I agree - its a very fine balance and some of those hot bits of ground pull me up at times too. Sounds sweet both ways - its annoying but I am prepared to sacrifice some depth to get a quiet threashold. With patches, the monos on the 4500 are very good and generally you will get a start - then hit it with every coil and trick you can imagine. There are some schools of thought about running the DD as mono, mono as DD. did a bit of a quick poll amongst users - DD as a DD, mono as a mono was the general consensus but its horses for courses I guess. (I know JP on his 4500 video recommends the reverse coil settings.)

I take a little notebook that has pre-written pages with blank 4500 settings marked. If I find a sweet setting I note the settings, coil, ground, temp etc and then its nice and safely written down. The factory presets are quite good IMO and I generally just play around these. I also spend at least a couple of hours doing tests at my test pit which is on horrible ground just to get my ear in and determine best setting for coils.

 

[nuggetino]

thanks for the tips loamer. Have just received my 24" DD coil and headed out to jupiter creek for a test run. I absolutely love this coil. Found some very deep targets with the 24" and checked them over before digging with my smaller mono and DD coils. No signal! I wound up with a 303 bullet at what must have been 75+cms and some rusty lump of iron trash at over a meter down. Hell of a work out but I was stoked at the fact that nobody had dug these signals (especially the 303 bullet) as they were in detecting hot spots. Swinging this coil around in the scrub for 7 hours did grow heavy on my shoulders though i hope to get used to it soon. I'd imagine many people avoid the big DD for that very reason. If I wasn't a young man built like the proverbial I could see myself struggling with this coil. Are there any favorite settings you use with this coil and have any luck with it in the goldfields?
I found myself running in DD mode, salt-coarse, gain 15, tracking on. It was whisper quiet. When I found a potential target I switched into sharp to confirm.

 

[dave14110]

Heard this little trick for detecting beach the other day in the detecting shop I go. On the DD coils that that are open in centre tie thick stiff cable tie to each end. As you swing two lines are left by cable ties attached to coil you can see exactly the ground covered. No more missed targets & every bit of ground detected. Thought this was a clever idea & worth sharing.