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Thanks to all for the replies,Stevewilko your tests are an eye opener and the settings will get me rolling nicely.Thankyou.
The avatar nugget was around the 9.5 ounce mark and was found in a rubbishy area at the end of a hot sticky and goldless day.
It was found in the maldon area which has produced numerous large bits for me so this coil may give me an edge.Lol.
Deepseeker,thanks for the advice on the skid plate that is one of my pet hates with the open coils. :cool:
 
Yeah; i remember paying out this dude in the comment section, because when he held it in his hands he said (around 5 ounces) it is nearly twice that LOL!
MaldonGold, now you have got me interested (numerous larger pieces) i have been to that area once but did not venture in very far, will definetly make plans to hit that area again, just a question for you: were all these nuggets found shallow like no more than 12inches, and do you believe there is some nice chunks deeper down still?
 
Hi Ironrock.The avatar nugget was a shallow find around 8 in deep in virgin yellow clay.I have also been lucky enough to find a 3 & 5oz in the area.
These nuggets were found at deeper depths between 1-2 feet.This area is of interest as the original creek has moved over millennia creating a paddock sized area
that has the potential for a few more clunkers,maybe.Lol. :pickshovel:
 
maldongold said:
Hi Ironrock.The avatar nugget was a shallow find around 8 in deep in virgin yellow clay.I have also been lucky enough to find a 3 & 5oz in the area.
These nuggets were found at deeper depths between 1-2 feet.This area is of interest as the original creek has moved over millennia creating a paddock sized area
that has the potential for a few more clunkers,maybe.Lol. :pickshovel:
Click to expand...

Keep us posted if you find any more. Good luck. :Y:
 
stevewilko said:
Hello maldongold.

I have the GPX 4800 / NF 25X DD combo.

A while ago, with some mates, I compiled this "for fun" test of detectors and coils which you might find interesting...

https://www.prospectingaustralia.co...ctor_and_coil_in_field_depth_test_results.pdf

If that link doesn't work try this one....

https://www.prospectingaustralia.com/forum/viewtopic.php?id=32051

Or - you can locate the topic in the "metal detecting for gold" index of the forum posts.

To answer your question about settings I have used anywhere from

General, Normal in factory preset modes but as a large DD I can open it's response with volume limit up, signal up and taget volume up - all just a little tweak.

Working off the side of diggings and away from deap lead areas I have dialled up the 4800 to the following -;

Deep
Special - Sharp
DD
Fixed tracking
Volume limit - Up x 2
Manual tune 70 - 90
Motion - Very Slow
RX gain - Up x 1 = 10
Audio - Deep
Stabilizer- Down to 2
Signal - Up x 2
Target Volume - Up x 4
Tracking - Slow

That you will find has it "fairly humming" !!
As a consequence the threshold is dialled down to still audible and pay no attention to the squarking.
You swing over metal it will tell you - no mistake!

And it is a 5 second 160 one direction swing ..

Cheers
stevewilko
Click to expand...

Thanks for sharing your experience stevewilko
I haven't come across any gold with mine yet. Have dug plenty of really deep holes for recent and old rubbish though. I know it is definitely a capable coil. Not unhappy to have gotten it.

This coil can keep you really fit.

Cheerrs
John
 
Any settings preferences to try?

I was digging on an old thread asking over here :

https://www.prospectingaustralia.com/forum/viewtopic.php?pid=438227#p438227

But thought Id just reask in a seperate topic.

Between the daylight and the mozzies I havent had time to really test yet, but I did sniff out what can only be described as a shard of gold using filter 1, volume 5, mode 1 tonight which was to say the least a pleasant surprise as I was only just setting up looking for the first bit of nasty ground I could find to start testing in.
 
my feel is that the sP01 settings are mostly about what best suits your own detector/coil combo & your hearing.
I usually run my sP01 on mode 2, filter 1, but with some coils on the GPX4000 I like filter 2
note; mode 1 is mono audio, mode 2 is stereo or more correctly for stereo wired twin speaker/headphones ... as the detector output is not stereo
 
Hi All
Im in the market for a new coil must be between 15-20 inch in size, so was just wondering what others have used and finds it works well .
Wanting something that punches deep.
Cheers
 
Howdy!

Overall - what detector are you using to drive your coil choice?

First thought to mind is to 'split the range' and perhaps concentrate on an 18" coil choice.

Mono for cone shaped detect pattern with depth.

Then to assume that the bench test / field test observations will show similar depth capability over the modern coil choices.

But then again, or in addition, the coil is only a comparitive component of all the factors in successful prospecting / detecting.

I havent seen a definitive 'side by side' comparison test on the new'ish Detech 18" concentric coil which might warrant further investigation because it is light but comments online suggest it needs an (are available) skid plate.

I would also look for a second hand late model coil to save capital. But that's me! I have long pockets and very short arms!

Trust these thoughts help you...
Cheers Wilko.
 
The theory behind a mono coil punching deeper is founded on the cone shaped field, so its extra depth is found in a small circle at the bottom of this field. A DD coil spreads the field wider at its bottom area, & whilst not equal to total depth of the mono, can give a deeper average penetration when ground conditions get hard & noise makes the mono difficult
 
I bought the Detech Concentric 18". My reasons;

1. It's lightweight. (almost 2/3 the weight of other brands.)
2. Comparable pricing.
3. It's stability on the ground. (In DD I've used it in General, Normal with Rx at 11 with no apparent instability.)
4. It gives the "best" of both worlds. (I can't say it's the best mono or DD for it's size, but it gives the option for a very stable DD and a full 18" mono all in the one coil).

On another thread, I noted the solid skid plate as problematic, but a sheet of ABS glued to the underside will fix this.
 
condor22 said:
I bought the Detech Concentric 18". My reasons;

1. It's lightweight. (almost 2/3 the weight of other brands.)
2. Comparable pricing.
3. It's stability on the ground. (In DD I've used it in General, Normal with Rx at 11 with no apparent instability.)
4. It gives the "best" of both worlds. (I can't say it's the best mono or DD for it's size, but it gives the option for a very stable DD and a full 18" mono all in the one coil).

On another thread, I noted the solid skid plate as problematic, but a sheet of ABS glued to the underside will fix this.
Click to expand...
What he said :Y:

Choosing a big coil for outright depth will be more about the ground & area IMO.
No use having a thumping big mono coil if the grounds noisy or EMI is an issue. Big coil = big antenna.
A large DD, Concentric or Anti Static coil may be more suitable/stable & still punch deep.
If the ground is reasonable & EMI limited to atmospheric conditions then the mono would be better in most circumstances.
 
Hi All,

I dont normally post but have been doing some reading on coils and have read on a few sites that coils over 18" in diameter are actually reaching a point that they do not give a positive return. That is on a GPX, some of the earlier models like the SD seem to benifet from larger coils from what people that have used them say.

I have no electronics background or a wealth of knowledge on this subject, its just an inquiry to see what people with more knowledge and first hand experience think on the subject.

I have recently bought a 20" mono and will be heading over to WA once it turns up, so will be interesting to put it up against my 14" on targets to see if it makes a difference. It will take time to change between the two but im hoping to be over there for six months plus so time is not a issue.

Do people think the reason that two of the major manufactures only have 18" coils at the moment is because of this, once again only a question to see what people with more knowledge than me think.

Regards,
Maurice.
 
mbasko said:
Coiltek still have 22" Goldstalker DD & Mono coils
Nugget Finder have a 25" DD coil
IMO big coils in the right area still have their place
Click to expand...

I certainly hope so, cant wait to try out the 20" in WA.

Pfft just cant wait to get out of Adelaide and detect full stop :)
 
I still have a round 24" DD coil somewhere in my collection. It certainly punches deeper than an 18" coil and on a test pit in highly mineralized ground will easily outdo a 20" Mono. I think the mono could do just as well or better in more benign soils mind you. Oh and aside from a few exhaustive meter+ holes recovering horse shoes and other lovely fuggets I never managed to find any gold with it. The fact I found some of these fuggets in flogged ground does lead me to believe it offers an edge on larger targets at depth over the common configurations.
 

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