Minelab Eureka gold tips, settings, questions

[argyle]

Hi MDV.

Yeah most definently an advantage. Should have been made years ago.

The 10x5 stock elliptical suffers from a slimming trumpet like cone from top to midsteam of the cone. The blade pattern simple cones down too sharply, causing a very thin hot spot at depth and a miss on signals too early from the tip and heel of the coil.
The new Coiltek 6" round coming out will carry a wider cone from the top to mid area of It's detection path. It will be a touch more sensitive and more maneuverable in tight areas.
I've got more coils than clothes, but I'm still going to get one.

 

[argyle]

Hi Au.
I hope you really get to like your unit. Only one other comes close, the 705 when set up correctly.
I'll have a crack at your questions for sure, just bare in mind that what I say suits me 100%, and you may like to set up or detect quite differently once you get the feel of your unit and how you like to go about things.

1.
If you only have the stock 10x5 then I'd definently only start detecting an area in 20khz.
That frequency will pick up pieces for you at a depth that the 60khz simply cannot reach far enough to respond to in any way.
You may work out in the end, as I did when I held a compulsive addiction to very small gold many years ago, that detecting in 60khz from the start in an area, will have you bypassing signals that you would've picked up on by the lower frequency's.
In 60khz, you are really only detecting an inch or so for very very small gold, (and wait till you have that sound working way up in your hearing, you can actually hear the internals of the machine tickling around every grain of dirt, it's like another dimension)
The only exception of coarse is larger pieces a bit deeper that it will hit. But the slightly deeper ones than that will be missed by the 60khz.

But, in 60khz, you will pick up many very very small pieces that 20khz will not.

2.
As for settings in any frequency, top volume, top sensitivity, the same tracking speed I was using on that ground type if it still suits the immediate area, normal signal - never fine or boost, and never in Fixed Balance as both tracking speeds will not be thrown off if the coil swing speed on that immediate ground suits the tracking speed your in.
Fixed Balance cannot change for you on a foot long swing, so you will not pick up a soft signal, mainly dropouts of threshold signals, in Fixed Balance when that ground changes, and it will change.
You gotta trust that tracking.

3.
What all call a Patch, but I call a Run, is I don't think ever quite 'cleaned out'.
But if the Eureka is only used there to start with, before bringing in other units, the 15" the 11" and the new 6" Coiltek coming out in a couple of weeks, and in the frequency's that suit each coil.
But more importantly is the coverage. The 15" has a 4" sweet spot at depth, It's located at the centre of the coil. So if you move each swing more forward than 4" further each swing with that coil you'll leave deep or soft signals un-heard. The 11" has around a 2.5" sweet spot at depth, the 10"x5" has quite a slim 1", and the new Coiltek 6" will have nearly an inch. Any further swing forward than those measurements will miss signals.
Then you have to detect by swinging N/S as well E/W with all those combinations. You just won't be able to stop yourself from doing that.

4.
Yep both those Minelab 11" and Coiltek WOT, best coil ever made, more sensitive than the 11" somehow, and much much deeper. It's the ideal size for depth too on a low frequency Vlf. That's the cut off point for coil size as any bigger and no more depth is obtained by making a larger one.

5.
I have a thing about talking about finds or selling local au.
I'd probably start a war if I told you the depth difference between one of these in particular that I've set up, in comparison to my gpx and sd's. But only with a detectable surface of fingernail size and up.
But I can tell you after years of changing coils and frequency's over targets, that I only detect with the 15" in 6.4khz, sometimes in 20khz but not often. And that this combination is the best to use.
I only use the Eureka on very hot ground.
The new 6" coil just may give me back an addiction to tiny gold, who knows.
The Eureka isn't the only unit I use, but It's one of the only 3 gold Vlf's I would ever bother to take out, it and the 305 and 705. But it is the best Vlf for gold detecting that's currently on the market today.
Made for hot ground, but mis-used by many.

 

[AU Fever]

Thanks argyle, very useful information to take into the field.

I will have to only use the stock 10" x 5" before I can afford the $300 for the Coiltek WOT, but that's OK it will give me plenty of time to practice with getting the sound working way up to my hearing. With a slim 1" depth sweet spot with this coil I'll defenitley need to spend more time covering an area than I have been.

I've generally been working very hot ground between Ballarat and Creswick, so I'm pleased to hear that the Eureka will handle this. I'm trying to find areas that most PI users haven't covered yet, but I guess in reality there's a pretty good chance that someone had been over it. I still do pick out my fair share of bullets though.

Just a question on tracking speed - how do you know when to use Slow or Fast tracking? Does this just come down to experience, or is there something you are particularly listening for?

Thanks again for your help.

Au

 

[argyle]

Don't worry at all if pulse induction units have been over the area you are just about to detect. The very same measurement of forward swing applies to our PI coils as it does to the Vlf's. And using a gpx or earlier model PI does not necessarily make a man into a thorough operator, in fact they tend to be much more sloppy in regards to obtaining true ground coverage than those that cut their teeth on Vlf's.

Fast tracking is the best mode in all ground I found. Both mad heavy ground as well as smoother deeper ground. It goes about it's buisness quicker and handles the correlation between the other settings in a way that just seems natural for the unit to behave in.
Slow tracking (when you have your set-up well up into your hearing of the internals) seems to want to play catch sometimes, it does not feel right in general detecting.
Except in 60khz. Slow tracking on any ground suits it because of the much slower movement of the coil you use. Plus the 60khz does not seek deep, so the tracking balance has far less work to do due to lower level of processing it has to do. Searching in 60khz is much like hearing in a miniature world. So the Slow track speed suits the gathering of information at that slow speed of the coil.

I don't know if you've seen those YouTube videos of guys throwing that elliptical coil around like a broom in high frequency, waiting for a booming screaming signal to come leaping out at them or not AU, But they are humorous to watch. (Most of them are Minelab dealers too)

Bullets are good! Especially the deeper un-dug signals off them. Do all your testing of settings on those feint deep targets before you even start scraping. Un-dug bullets on worked over ground means in-dug gold.

Best of luck for the weekend.

 

[bob]

Thanks Argyle for your input. I enjoy using my Eureka even though I have found no gold with it yet. I'm like Au in that I have only got a 10" elliptical coil and generally detect in 20 kHz. I'm encouraged by the fact that I have found lots of 22 bullet heads as well as lead shot and shot gun pellets and some interesting coins. I think my main fault is not searching thoroughly enough. I will also put in some time on setting up each time I go out. I have been wondering about other coils and it sounds as if I should start saving or put in an early letter to Santa. It has taken a while to get this post going but with your input it is becoming a valuable resource.

Cheers and good luck Bob.

 

[argyle]

Hi Bob.

It's a pity I guess that we cannot choose a coil size at the purchase time of a unit, but that's across the board with all manufacturers. So it ends up costing us much more to finally set up a detector how we like it.

One thing I really should have mentioned are the types of signals gold gives.
Almost excact to the bullets, especially the deeper ones, you've been finding.

The loud signals of close to the surface targets are unmissable of coarse. But most gold, apart from largish screamers close under the coil, have a lovely 'Dong' type sound on these detectors. It has been that way through the entire range of Minelab gold Vlf's, the XTerrra being the only exception.
Here are the signals we must pick up on while we are listening to the unit working, the ground change, and the ever present mineralization in the form of groans, pips pops and squeals. Of which nearly all can be deadened enough to work through the ground with confidence, by having the settings at their best levels over that ground.

Depending on coil size and frequency used, the signals below would differ on each combination. Hence our need for different size coils and the frequency used in correlation to the ground we are on ie: ground we think is shallow - meaning you don't think gold would be held deep, deep ground that wouldn't hold gold near the surface, just how heavy (mineralized) the ground is ect.

There are 4 types of threshold signals that are made on the deeper gold targets.

1. Threshold Rise:

These are the signals that are well under a signal response, so they make a slight rise in threshold, repeatable and excact from all angles, unlike clay domes.
Just not a big enough signal due to depth or size, to cause even a slight 'dong'.

2. Threshold Suck:

If on the same ground as above, but the piece is a bit deeper, it will draw the threshold down instead, giving the impression of trying to suck it down. But the piece isn't deep enough yet to cause a quick break in the threshold ...a dropout.

3. "Dropout 'Dong' Dropout"

When the piece is again deeper than the above, it will produce a very quick dropout of threshold, then a very slight feint 'dong', then the other side of the dropout. It is a nice even signal of it's own. Unmissable.

4. Full Dropout:

The piece is deeper again than above, but so much deeper that it cannot produce even a very slight dong. A full quick dropout is simply a nice quick compleat dropout of threshold, pure blank, but only along the deepest part of the DD coil, the centre of it. On the 10"x5" stock elliptical coil, these signals will only be heard at depth, when in under that inch of the centre of the coil. Move the coil two or three inches forward each swing at a time and these signals cannot be picked up.

These are the true deep signals. They come in clear, especially on the bigger coils. They are so clear that you start getting used to sizing the piece by simply moving the coil left to right back from it then forward again. Once you get used to a coil and frequency combination, the judgement of size and depth of a target gets easier.

Thankfully we have the most rock-solid 'True' threshold ever designed on a detector to work with. That threshold is everything!

 

[AU Fever]

Hi argyle, I couldn't get to the goldfields today but did get a few hours to practice in the vacant lot across the road. The ground in not mineralized at all, but is full of trash.

I started by turning the threshold up to about 3 o'clock and balancing as you said. Full volume and sensitivity, audio on normal, all metal mode. First thing I tested was a small vial of flour gold from Sovereign Hill (maybe 0.05g). At 60kHz I was getting a small threshold rise with the vial directly under the coil, but only down the centre from the nose to the heel. The signal was a little stronger if I ran the vial across the top of the coil. To be honest I couldn't really pick any difference between the 1" sweet spot in the middle and the rest of the centre of the coil.
Next I tried the same test at 20kHz. I could just discern a slight threshold rise underneath the coil, which again was a little stronger over the top of the coil.

Next test was an air rifle pellet, firstly at about 1". Different frequencies gave different signals as you mentioned in your last post. The I pushed the air rifle pellet into the ground at bout 4". 60kHz barely recognised it, 20kHz gave me a threshold rise and 6.4kHz gave me a "dropout, dong, dropout".

I moved on to a small piece of ground (about a square metre) that I'd been over before and has previously cleared some of the trash out when I first got the detector. I started out at 20kHz and pulled out a few screamers that were pieces of iron, roofing screws, 3" nails etc near the surface. Then I went over the same ground again and started pulling out small pieces of Al foil and some small pieces of nails. At this point I could really concentrate on any threshold changes and continued to dig out tiny pieces of wire or little pieces of iron smaller than a pea at depths up to about 4" or so.

For the heck of it I then tried 6.4kHz over the same ground again and could hear some very tiny changes in threshold. I was amazed at how small some of these targets were when I dug them out. There was even a couple where I would dig them out of the hole and then lose them in the dirt pile. But a quick flick into 60kHz would find them easy again.

I'm feeling a lot more confident with the Eureka after trying some of your tips. In the lower frequencies it now seems a lot easier to discern between the tracking noises and the targets. At 60kHz I still need more practice, as you said it's like being in another dimension but I'll get there.

I need to get an amplifier, as currently I'm using Apple earbuds - but since I'm pretty handy at electronics I'm going to build one of these: http://tangentsoft.net/audio/cmoy-tutorial/ That should help a lot.

Thanks again for your help. I was almost at the stage where I was going to sell the Eureka and get a 2nd hand SD, but now I will persevere with it.

Au

 

[argyle]

Hi Au.

That sweet spot at depth at the centre of the coil can really only be discerned In the ground at depth, solid un dug ground over a target.
When you do hit the goldfields next time, find a costean or an embankment and go inunder about six inches down, actually make a few holes at different depths, and plant some squashed sinkers of different sizes in them, then detect down on them. Try not to disturb too much ground as you drill or dig out those holes, and makes sure they go far enough in that the coil dosent lip over the costean or embankment edge. That's the closest you'll get to the sound of real un-dug targets.Those amps look okay and would be a good project. But I've never yet heard one that dosent sound 'tinny' and useless. Better off buying a b@z or second hand version of another make. Even though they are all quite cheaply made, they are excellent for tone quality of sound.
RPG's suit these detectors so well, as do a lot of old or new 8ohm and 32ohm headphones.
The flour or many flakes of gold in a vial aren't good to test with, they read the same as some necklace jewellery does.

 

[Craigo]

Ive only recently bought a Eureka myself, found plenty of trash with it and no gold as yourselves, I was contemplating the 11" upgrade on the coil shortly enough. But I have read this thread a few times and it helps spell out a few mysteries.

argyle is there any way you could get some audio on the threshold changes?? Recently on Durikai I was getting a few patchy dropout type noises 20khz but dismissed it as hot ground as it was about 9 ft wide and couldnt stabilise the signal as the coil passed over these areas....... Not really any helpful you tube vids on the Eureka compared to the CD/SD/GP series machines to help hear these noises.

 

[bob]

Hi Craigo
It would seem that the Eureka is an underestimated and forgotten detector when it comes to information on how to use it effectively. I guess it is due to the success and popularity of the GPX series. I have tried researching and the most common thread of advice is to get out as often as possible and listen carefully to your machine. Argyle's contribution is the best I have read so far. His feedback was very encouraging because I was getting a little frustrated with comments like "sell it and buy a GPX."
I cannot help explain your "drop out" experiences but I would suggest you follow some advice in the instruction booklet and that is when a strange situation occurs dig and see if you can find a reason for the signal or lack of it. When I first started I decided I would do just that. I have gained some experience and can now approximate depth i.e. surface, shallow, deep. I try to predict the target by its sound. If the target is within six inches of the surface I can usually correctly pick lead, brass or iron. "Iffy" signals get a boot scrape, if they persist then a scrape with the pick. If it persists then I'll take a few centimetres of the top. It is surprising what the detector will react to at times. Buried charcoal for instance. On the surface the detector ignores it but buried sends it off in a strange way like a signal but not. Digging usually answers some of the questions. Once I started to pick lead they were exciting digs because I could not and still cannot tell the difference between a bullet head and the gold sample that I practise on. Now when I hear that tone I expect to pick up a piece of lead. One day I hope I'm wrong and it will be gold instead.
I have added an 11" goldsearch coil to my kit along with a set of RPG headphones. I have used them about six times. Argyle should have put a warning in his advice as I have dug some very deep holes. Horse shoes three of them and a 2" piece of 1'' pipe, way down deeper than I have found things before. They were exciting digs down in dirt you would seriously consider panning. Quiet signals at first barely noticeable, a scrape confirmed a signal. As I dug deeper the signal strengthened. Classic stuff as written in Gold, Treasure and Gem. Then halfway to China the signal changes to that familiar ferrous sound. Well it was fun to dream and wonder but in each instance I completed the dig just to find the answer. I'm now thinking how they got so deep. So detect lots, scrape and dig suspect noises unless you have an experienced user in your area to help, you are on your own like the rest of us Eureka operators. Be patient it isn't easy; I have met a few GPX users in the bush and if what they say is true then they're not doing any better than me.
Good luck Bob.

 

[Craigo]

Cheers Bob, and thanks for adding a valuable 2 cents worth. I have maybe clocked up 20hrs max of play time and I don't expect to find any yella for another 100hrs realistically hahaha! But, even in my lack of experience I agree the Eureka has a great potential as a very potent machine if it got that aftermarket attention and support that the GPX Series has had.

I'm headed down to Kilkivan for a couple of days to get a little more fun and excitement in

 

[Golden Tiger]

Hello fellow prospectors,

Coiltek as a brand, Are they worth it? and if yes....

Has anyone heard anything or tried the new Coiltek 6" Goldseeker Coil for the Minelab Eureka Gold?

I was wondering if it is worth the investment or should i just save for my dream detector?

Cheers,

GT

 

[Diggerdude]

I have a little coiltek coil 5 or 6" can't remember. I don't bother with it as my 11" coil picks up gold just as small, and covers a lot more ground. May be handy if your in lots of crevices etc. Mines on 5k btw , haven't used it on a eureka.

DD

 

[Brumble-Gum]

Hi GT
I use a 6" coil on my 5000. I use it for dry creeks, gullies and when I look for specimens on/in quartz veins.
It is a specialist coil and one I always carry with me no matter where I go. It is also good on high EMI areas with little of no interference.
Coiltek make great coils as do the other after market coil manufacturers.
I hope this helps.

 

[Golden Tiger]

Hey Brumble-Gum,

Thanks for your post.

What type of depth do you get out of the 6" coil on your 5000?

I believe with the 6" Coil for Eureka Gold is best used in 60 khz setting and only gets a depth of 1 - 1.5 inch's deep.

 

[Brumble-Gum]

I pulled a piece of quartz with 8 grams of gold at about 2 feet down, the piece was about the size of a grapefruit with the gold spread throughout.
It picks up sub-grammers no more than 5 inches in compact river gravel. Hard rock creeks with crevices are it's forte. A VLF at 60 would be better on the small stuff. It all adds up.

 

[Goldpick]

I've got the 6" Coiltek on my xt17000, mainly since I don't have the original eliptical coil for the 32kHz setting. It picks up a 0.4 grammer with ease a few inches down, but I'm not sure whether it will be better than the stock eliptical coil on the Eureka. It certainly is good for detecting in thick scrub, doesn't manage to get caught up like the larger coils do.

 

[Golden Tiger]

Thanks guys. I'm sure Miners Den will appreciate your persuasion, but I'm pretty sure the wife won't.

 

[Goldpick]

I don't think comparing a 6" coil on a PI gpx5000 to one on a vlf Eureka or xt17000 is really a fair comparison (let me know if I'm wrong), two completely different detectors with completely different depth capabilities.

 

[Big bryza]

Hi all, am new to this be easy on me lol. Have had a history in gold prospecting mainly dredging ( before it was banned) and gold panning, not so much detecting, but have just bought a eureka gold detector for $930 it has only been used twice! Was looking at the x terra gold pack for $850 but miners den tell me the eureka is a better detector! You get what you pay for right? They retail for $1,190 of course I know they want the bigger sale! I guess my question is have I made the right decision? I have read a few bad reports bout the eureka, and good, it's confusing to a newbie! I know it takes time to learn the detector and can't wait to get out in the field! Live in bendigo so not far to travel! Much thanks in advance for any opinions or hints whether good or bad, cheers