Anybody used the ferrite ?

G'day all was wondering has anybody tried ground balancing with the supplied ferrite ? How have the results been for u ?

Not me. I haven't encountered cases where I would have needed it. Will get one next week though, just to have in the kit.

Those who purchased their GPZ-7000 through CWPS Mudgee will be receiving theirs shorty...we started packing them today and will be sending tomorrow.

And yes iv used one...in the shop...not on the ground. For demonstration purposes, they work a treat.

yep, worked a treat.
best gb ive had since owning the machine, and two nuggets that together did not even move the scales.

Not yet got it today. Will try it on the weekend

Hi Musket,
Gave the ferrite a try on Saturday. It made a very stable machine even more stable! Will continue to use it.
Cheers,
bowy

used mine to GB on the weekend.....a vastly different machine and so quiet this time..........very happy with this aid..........pity Minelab didn't get their act together at the time of launch

Interesting, thanks for the feedback.

Do you loose any performance or sensitivity when ground balancing with the ferrite?

Cheers.

my experience with it is that the detector is much more stable and hence more sensitive because of that.
the day i used it i found 2 small pieces that jumped out of the ground at me and together did not even move my scales.

hoolahoopa wrote:my experience with it is that the detector is much more stable and hence more sensitive because of that.
the day i used it i found 2 small pieces that jumped out of the ground at me and together did not even move my scales.

Ok wow, thats impressive. Are you using auto tracking on?

cheers.

Jay.

Before the ferrite aid balance I was experiencing a noisy machine that masked the subtle signals from small targets........also as Minelab were very tardy in their help and advice for those of us that purchased in the early stages I (like many others) were applying some the detecting techniques that we had used on previous machines (4500 and 5000) to the new ones not realising the subtle and not so subtle differences in the technology

Basically I think that if a new chum first out detecting may have had a better chance at success than those of us that applied previous knowledge not realising that in some cases our prior knowledge was a negative !

So in summary the differences I applied this time with the Bruce Candy publications........JP's videos's....... the ferrite...........and a greater understanding of the technology the following were my revised techniques

• Set the machine to factory reset
  Took the skid-plate off and inserted a small piece of foam dead centre between the coil and plate to remove the hollow between)
  Kept the machine 30mm off the ground as against scraping the ground
  Went slower and listned more closely to the very subtle target sounds.........for example.....I will try and describe the target noise as I read it......the 5000 on a small target has a high distinct peak (large sharp hill)....the 2300 has a very loud target noise ..(it barks at you like a sharp mountain peak).........the 7000 is more of a subtle blimp (or rounded hill noise)......very easy to miss if you don't have the GB very stable and you are not focussed to the smallest change and going slow enough to give you and the machine time to react.....also might be a big coil but a small target needs to be almost exactly under the damn thing to react....the 2300 barks when you approach the target !...........the 5000 is more forgiving nearby a target.........the 7000 has to be right positioned near perfectly to alert you to the target
  All the above re target noise I refer to a small target....still waiting for a large target to know what it sounds like
  Purchased new boots....I always have warn a boot that was not steel capped and did not react to a magnet but always gave the coil a sharp reading if I walked too close behind the coil....never bothered me in fact I used to on occasions deliberately move my boot to the coil vicinity to "wake it up"  to see if all working if the silence and no target and I started to need some reassuring it was working !  
  So new boots...no reaction on coil at all.........
  Reason being the 7000 upon receiving an inadvertent boot signal (or pick etc.) takes that metallic object into its auto GB calculations and stuffs up the auto GB for a period
  Also the new harness and machine together with the larger coil seems to hang marginally closer to my body (read boots) and therefore I have eliminated the inadvertent boot signal
  Finally never touched the quick track button after first set up.........and was happy to turn the machine off if stopping for a period (large hole or smoko) happy in the knowledge that it would resume where it left off in that same ground with its setting and GB..it keeps in memory
   
  

The result?........a vastly quieter machine.......and if GB gets a little noisy I slow down and give it time to sort itself out on that ground......yes I got a few tiny ones and some shotgun pellets so now looking forward to my next trip and a larger target noise

Hi all,

I've kept quiet on this forum about my sad experiences with my 7000 but I think it's time I had a swing. I have a huge number of posts on Finders about my troubles and I've seen just about all there is to read ,,,,,,,,,,,but I'm still looking. I've had all the issues that Bungarra has had and I reckon this the worst detector that ML have ever brought out. I've been using ML machines almost continuously since 1983 and I've been a pro-prospector in my time.

This comment from Bungarra is a worry and it's one that I've thought about often as I'm wandering:

",,,also might be a big coil but a small target needs to be almost exactly under the damn thing to react....the 2300 barks when you approach the target !...........the 5000 is more forgiving nearby a target.........the 7000 has to be right positioned near perfectly to alert you to the target,,,"

I've had this as well. I often feel that a 5000 will give you a target even if it's not right under the coil. This is courtesy of being able to use a mono coil. But the blade like search pattern of the 7000 resembles a DD but far worse in it's downside. A standard DD will give you some power across its diameter and as far as the extreme of it's circumference. I maintain that the 7000 won't give you that concession. Its centre has to be DIRECTLY over the target. This is a great concern as it severely reduces the search "percentages" pattern. If we only get 10% on the circumference giving us "power" as opposed to the 85% of a standard DD at the circumference, then we have another reason to bag the 7000,,,,,,,,,,,and I have enough already!

Additionally, it seems to me that the central loop of the 7000 coil, the smaller one, is the one that signals the small bits. One could say that this smaller coil (within a coil) is the "2300 part" of the 7000. Let's assume just that in the absence of alternative views.

So one would have to travel really SLOW to get that small "2300 loop" to obtain 100% cover on any given area and thus be assured that you have done it all. So an overlap of say 8 inches on this 14 inch coil would miss targets - when chaining for instance. You'd need to overlap by at least 3 inches and that vastly increases "time vs cost vs return". So, from that can we assume that swinging a 7000 quickly, like 5000, is definitely not the way to do it? But can we also assume that we'll be swinging a long time on an area no bigger than a 1/4 acre house block?

Hmmm,,,,,,,it could take centuries to cover the WA fields at that rate. I'm not sure I have that much patience for 0.1 grammers and I certainly don't have that many years left either!!

Ichi, I was going to ignore this post as someone trying to stir the pot, due to the obvious miss-understanding of the the Z coils, and the assumptions regarding the way that signals sound, but it got to me as it seems so far from the truth as others see its operation.

The small coil does not detect any signals at all, it is the transmit coil.  The two coils on each side are the receive coils and it is because of their position that the Z tends to give a DOUBLE signal on small targets that are close to the surface.  Absolutely no need to be centered over the target, especially if it is near the surface.  Bring any metal object close to the coil from the side and see what happens, it will indicate a target without needing to be centered over it.

What is this "2300 part" of the 7000?  The 2300 and 7000 use completely different methods and the smaller coil has no relationship to the 2300 other than it is a transmit coil.

The people who have been reporting great finds with the Z on this forum and others, are not having the concerns that you are noting, so either your machine is faulty, you are using settings that are not appropriate for the conditions, or you aren't walking over the targets.

Well Pablo, I'm glad you didn't because I've learnt something.

My 7000 went back to ML last Tuesday and I'm waiting for a verdict. My settings & technique are those advised by JP himself in a personal phone call. Thanks JP it all helps but it's still no good.

However, as Bungarra says, if it ain't directly under the coil dead centre then you'll miss it. Does that sound right to you?

Thank you, Pablo

ichi-ban wrote:

However, as Bungarra says, if it ain't directly under the coil dead centre then you'll miss it. Does that sound right to you?

Thank you, Pablo

Nope it doesn't sound right for all signals as what you will hear will depend on the size and depth of the target. I was going to try and make up a couple of graphs to explain, but first have a go at reading page 52 of the manual as that gives a reasonable explanation of why you can get two peaks for shallow targets and how to use that information when pin pointing.

I received mine free from Bendigo Gold World, I never used it because I never find ground so difficult to balance that justifies the use of ferrite, but it is good to have it and I tank the guys at Miners Den for their good after sale service.

Not related to the Ferrite, but the earlier posts from Bungarra, Ichi & myself, I have made a couple of simple drawings to try and explain the sounds that can be heard with the Z, depending on size & depth.  I have only shown small target at shallow & at depth, but a response from a larger/strong signal target will tend to be picked up by both coils even if close to the surface, due to the target response signal level.

If the target is close to the surface, as one of the receive coils passes over it then it will provide a response, then the second receive coil will do the same as it passes over the target,  But when the target is deeper, both coils will tend to pick up a response, perhaps with a slightly broader sound.



I hope that this helps.

Nice explanation pablop

ichi-ban,  I've been following your experiences over on Finders and feel sorry for you and the anguish you're going through.

I get the feeling your coil must surely be a dud, especially if you only get a central response. The worst part about all this is, even with a new coil and properly running 7 you may never regain any confidence you first had in this amazing machine, and reap the benefits of your investment.

I think Minelab have not learned from the GP Extreme release with respect to qualty control. ISO certified companies should have checks and balances in place to ensure that people should never go through what you have experienced.

8 ozt of yellow can come in one hole for some, for others it's many days of bleeding sweet and blisters, blinding heat, dirt and flies, thirst, sunburn, hours of wandering with feet on fire and an itchy smelly backside, so all that in exchange for a 7 for some of us is a hell of an investment.

We have a damned right to be annoyed when they stuff up; that yellow represents days of your life that you can never ever get back.

I hope it all gets sorted for you mate and you can keep your sanity, sense of humour and marriage intact.

I have been amazed at the number of bits, quarter gram and over that I've found way to the side of the coil under bushes, tussocks, rocks and logs. The side spread of the field must be greater than any previous unit coil combination out there. That is why I feel your coil is a dud. Hopefully you will get to see the real power of the Z.

Bungarra, there's a possibility your coil could have issues too. Check to make sure you can air test a 5 cent piece up to 18 inches, (high yield - normal ) and you get the double signal as pablop has described with a little bit. You should also be able to hear a bigger bit well to the side of the approaching coil. I've heard of a couple of dud coils now being bad from the factory.

Cheers.
Kev

Hi Alchemist...thanks for your comment re test.......so If I am read your suggestion correctly...........

A 5c piece on the ground...........The coil approx. 18" off the ground and listen for the expected double signal
Something bigger than the 5c on the ground to the side and expect to pick up a signal as I approach?.......that will be a first a signal approaching ....more like the previous coils.......

Not in the goldfields at the moment but the ground on our property is very sandy and non mineralised hence the settings of normal should give the coil a good test?

I am still not happy.......re my  post giving a score of 4 out of 10! ...........I have raised that to 7 after my last trip as above....so it hopefully I will keep lifting the rating..........on the assumption the test you suggest gives a positive result

Thanks

Pablo, Kev and others,

Now this is getting interesting. I was amazed at this machine for the first two days. It was getting 0.1 at stupid depths, only one nice soft "bip",,,,,,,and then it all stopped. Since then I've only had a meagre ration of bits, near the surface and NO DOUBLE BIPS that Pablo reckons is the way it works. Just a single "bip" but a definite "stopper" on each target. But no depth. It used to "hear" my belt mounted pick but it no longer does that and I can walk around with my pick on my belt almost at the front or my hip with no indications that its there.

More importantly, after the performance drop off, we did a load of depth tests on a static test pad of larger sizes of pre-buried targets. They've been there for months and used regularly for students at my mate's place. We also have a measured air test with a 50 coin on the surface. The results for 7000 were disappointing, hardly better than a 5000 with an 11' mono. The 5000 actually creamed the 7000 on one of buried test targets! That was very upsetting. I was visually angry by then and my mates reckoned I was gonna wrap it round the nearest mulga tree! It was embarrassing to witness an 11,000 dollar machine being equalled and even thrashed by a machine nearly half the price & using a smaller coil.

However, back to the 50 cent coin air test,,,,,,,,the best result I could get with the 7000 was a very subtle 560 mm or a tad over 18.5 inches. Fot that test, the 7000 was set on "Normal High Yeild". When reduced to "Difficult High Yeild" that distance fell to 520mm. The 5000 with an 11 inch mono set on "Normal" got the coin at 550mm!! Yet you can easily obtain that distance with a 5 cent coin with your 7000!! Plus, unless the target "to the side" is a big tin can or my car there is no great side power such as you've described. Even then it's no further than you'd experience with a 5000. There's something amiss here??

I'm holding back on the rest of the test results as I wait for ML to give me a verdict on my machine.

This statement from "alchemist" is the way I feel right now,,,,,The worst part about all this is, even with a new coil and properly running 7 you may never regain any confidence you first had in this amazing machine, and reap the benefits of your investment. You can say that again! Because it isn't an amazing machine and my investment is USC.

ML have learned nothing since the coil failures of the SD2000. There's a guy in Vic that has now had 2 new control boxes and FOUR new coils!! I have a pretty rough vid of him getting signals as the coil lightly brushes leaf litter, no more contact than would occur when detecting normally. The litany of 'first out" lemons goes back way further than the Extreme. It happened to me again & again. It's very bad look for ML and the real downside for them is that I (we) now assume the worst when we can't find gold with a new machine. e.g It's not me, it's Minelab". That's not healthy - for either of us. I've been a customer of ML for 30 odd years but this is really getting me down. Since CODAN took over it's even worse. They dispensed with Nenad Leonic who was the best ambassador they ever had. That makes me wonder if ML management really give a toss.

bungarra wrote:
A 5c piece on the ground...........The coil approx. 18" off the ground and listen for the expected double signal
Something bigger than the 5c on the ground to the side and expect to pick up a signal as I approach?.......that will be a first a signal approaching ....more like the previous coils.......
Thanks

Don't worry about GB just put your detector on the ground with the coil flat and do a noise cancel.
Reduce your gain until it's nice and stable, then wave a 5c over your coil in the air.

I can get a solid response at 17 to 18 inches on a gain of 1 ( I can't lift gain above 1 as there's a 33kV mains transformer 25 metres from my house)

The double blip occurs only on smaller targets close to the coil.

The great side detection I'm getting is mainly on bits over 0.2 grams not tiddlers so much.

Cheers.

"A gain of one"!!

I'm using a gain of up to 12 and run out of signal response at 560 mm on a "FIFTY CENT" coin! That's about 6 to 8 times the mass of a 5 cent coin for crying out loud.

I'm getting angrier every day Minelab!

(BTW - if you want to do some comparison testing it has been proven that the Australian coinage - 5, 10, 20 and 50 cent coins are as close as you can get to gold for conductivity. Lead is not good. Using nuggets is not good for comparison as the surface texture and the mass is variable. But coins do give a simple method of standardising the target if not the overall test method.)

Thanks for your thoughts everybody.

ichi-ban wrote:Pablo, Kev and others,

Now this is getting interesting. I was amazed at this machine for the first two days. It was getting 0.1 at stupid depths, only one nice soft "bip",,,,,,,and then it all stopped. .

Hold those thoughts about how it was ichi-ban, because that's how it's meant to be.

You discover a new patch and at the end of the day walk off with more gold in your pocket than you would with any other coil/machine/timing combination.

I would be extremely surprised if minelab say your machine is fine. It sure sounds to me like your coil or more likely one of the bridge FETs has failed, infant mortality is high for switching FETs in applications like this.

The extreme supreme debacle,  if minelab had remained private their QC learnings would likely not have been repeated over and over again, but multi-nationals are heartless juganauts that seem to make the most unprofitable decisions imaginable.

When you get your 7 back, follow Nenad's tips and tricks, he seems to get to the nub of the matter simple and sensible.

Nenad's tips

Cheers.

Agree regarding only the little targets causing the double sound, others a bit larger can tend to give a broader sound.

Just one little point regarding "but multi-nationals are heartless juganauts that seem to make the most unprofitable decisions imaginable", Codan may be selling internationally, but it is an Australian company based in SA.

There is no doubt in my mind that either the coil, the processor, or both have issues, so best to wait to see what happens when the unit is returned and take it from there. There are too many people having great successes for this to be other than a dud.

Again not related to the Ferrite but in regards to the DOD coil as "padlop" has mentioned.

Is the a way to work out what size Mono coil would be the equivalent to 14" DOD coil ?

Thanks.

True Rob, SA based, but they own a number of offshore companies, and as far as Minelab are concerned, I read that it was US logistics that were driving the Z release?

I've been thinking about the similarities with the GP Extreme release and the Z release. I wouldn't be at all surprised if component derating tolerances were not strict enough on the Z. This would explain why there are very hot ones, mild ones, fridgid ones, and everything in between.

If the Extreme scenario is extended further we will see the Rev 2 of the Z derated in performance to make all units reasonably equivalent in performance.
When would Rev 2 or 3 start, has it already started?

Whatever way, if you have a very hot Z hang onto it, because there wont be anymore until the 8000 or whatever comes along.

This could be total tripe, I'm just extrapolating what ifs based on past history, but we all know history repeats ad nauseum.

Sorry I've totally wandered off the torroid track, I'm bad at waffling off topic. Does anyone know the type...? 25 maybe?

Cheers

crowbar wrote:Again not related to the Ferrite but in regards to the DOD coil as "padlop" has mentioned.

Is the a way to work out what size Mono coil would be the equivalent to 14" DOD coil ?

Thanks.

I don't know of any, but Minelab used the 11" mono in most of the comparison data presented in the blurb, so they must hold this as an equivalent otherwise they would realise they would be berated for a seeming unfair comparison of a 14" to an 11".

The surface area, and by extention the number of turns of the RX coils could be the factor, but it's effectively comparing VLF to PI.

I guess the crudest comparison is mono to DD. A 14"DD is comparable to an 11" mono by virtue of the RX coil dimensions.

More waffle I'm sorry, I should've stopped at I don't know

I mentioned earlier in this thread that I have yet to use the Ferrite, and that I hadn't felt that I had a need to do so, so far. But as I have now got mine from MinersDen, I will be doing some playing when next out in the bush (far too noisy in town), in particular seeing what impact it has with some noisy charcoal targets if I find any and also a couple of hot rocks that I keep as "play toys". These are the two target types that have caused me to dig more holes than I would have liked.

ichi-ban wrote:"A gain of one"!!

I'm using a gain of up to 12 and run out of signal response at 560 mm on a "FIFTY CENT" coin! That's about 6 to 8 times the mass of a 5 cent coin for crying out loud.

I'm getting angrier every day Minelab!

Thanks for your thoughts everybody.

ichi-ban I'm not saying mine is a "hot" one, I don't have others to compare it too, but it finds gold easily. I think it is a standard, medium, average 7.

It is likely that the real hot ones and the lousy ones are a bit "unstable" the former at switch on while running cold and the later while running hot. This is again conjecture, I'm just trying to get my head around this whole thing.

Remember the original Minelab test reports made a point of spelling out the fact that "you can't find gold where there isn't any" this was in my mind, and it has been borne out by my own experience, another way of saying.........in many situations, if you have done an area with a GPX you may not find anything, but those bits that were previously missed by operators, and not the machine.

The old analogy of matching the right tool for the job applies, there are certain situations where the 7 technology shines, I think a number of people gave up too soon, there's a lot more to this than meets the eyes, Bruce has done the math, it's up to us to prove it, if we persist we will crack it. So when you get your 7 back ichi-ban give it a good whirl, but don't let test bed statistics fool you, and ruin your remaining faith, you can't replicate real life conditions in a test bed that set the 7 apart from all previous machines.

Cheers
Kev.

P.S.
Bruce was right on the money!
quote"
Shallow Soils
When searching in previously well‑detected shallow
soils that have been previously detected with a
GPX 5000, it is likely all of the larger gold nuggets have been found
because it is easily detectable at shallow depths, and only the
smaller pieces remain. Hence in these locations, only operate the
GPZ 7000 using High Yield, and do not use Extra Deep because this
does not detect small gold well.
To find deeper larger nuggets, you need to seek out deeper soils.
Generally, many of the most well known gold fields that have
often been detected with the GPX 5000 tend to be shallow (but
by no means all), whereas the deeper fields are generally not so
well‑known because overall fewer nuggets (mostly fewer small/
medium nuggets) have been found in these fields.
Saline Soils
Whilst the GPZ 7000 does not have a dedicated ‘salt’
detection setting (saline soils), the best Gold Mode
setting for salt soils is Extra Deep."unquote

source: Minelab white paper KBA_24-1 ZVT Technology.pdf

pablop wrote:I mentioned earlier in this thread that I have yet to use the Ferrite, and that I hadn't felt that I had a need to do so, so far.  But as I have now got mine from MinersDen, I will be doing some playing when next out in the bush (far too noisy in town), in particular seeing what impact it has with some noisy charcoal targets if I find any and also a couple of hot rocks that I keep as "play toys".  These are the two target types that have caused me to dig more holes than I would have liked.  

Keen to know how you go pablop.

I've not had any problems that would alert me to using this, but if it does give some advantage, I'll be doing the octopus walk thing I guess.