First full dig with the Impact UK

First full dig with the Impact.
Today's dig was on undisturbed pasture so any finds were likely to be deep there were 2 Impacts on the field today.

I set up using the following settings Deep 5kHz gain 94 the rest were factory defaults, tried to ground balance and found it would not so i dropped the gain to 60 and still it would not GB then i tried another spot this time it did GB, the first signal was loud and turned out to be part of a cauldron it was about 10 inches down i then got a scratchy signal with a vdi of 75 this turned out to be a pea sized musket ball at about 8 inches, i got a few more bits of lead again they were scratchy sounding.

I had some more trouble ground balancing and so did my m8 Ken with his Impact it seemed to be hit and miss if it would for both of us,we also found out that we could not get the same GB number mine was always 10 or so higher than his even with the exact same settings.

We crossed checked all our signals with various modes the best for us were Deep followed by D14 then D99 i then got a scratchy signal that was a George 3rd half penny at around 13 inches so the Impact has got some punch, the Impact run fairly stable @ 5kHz but on 14 and 20 it was very chattery the impact does not like been near other detectors including other Impacts,all the signals we got today were cross checked with all 3 frequencies and they all got the signals.

I found the upper stem has a bit of play in it at the joint when you press down on the coil lightly (others have said this) and the armcup is too wide even with a coat on so i had to use the strap (i will make some inserts to make it tighter) all my signals were a bit scratchy but they were deep, we both found the display hard to see for what mode we were in and for changing settings,balance is good and its easy to swing which i did for 7 hours,battery meter was on 3 bars at then end of the day, the VDI locks on good, i found 4 coins,buckle,musket balls,lead and got fooled twice by deep iron.

Good report Mark, what was your mineral bar reading?



Edited 1 time(s). Last edit at 04/09/2017 07:57PM by ghound.

In my opinion, Ground Balance numbers are very sensitive to quite small discrepancies / calibration differences in a machine/coil. A difference of 10 points doesn't represent much in terms of ground phase, and ultimately, as long as the machine is correctly ground-balanced, the number it indicates is not too important. It would be nice if there was more consistency, as comparing one site / machine to another would make more sense. It should be possible to force a ground balance to a length of ferrite rod, (which is a pretty repeatable object), and see if your two machines are 'offset' by the same amount as seen in the field.

Regarding the armcup, it's probably worth buying some adhesive-backed foam sheet, cutting it to suit, and thickening-up your armcup padding. This sort of thing:
[www.ebay.co.uk]

ghound Wrote:
-------------------------------------------------------
> Good report Mark, what was your mineral bar readin
> g?


it was between zero bars and one (i know you are waiting to see how well it does in mineralized soil)

Pimento Wrote:
-------------------------------------------------------
> In my opinion, Ground Balance numbers are very sen
> sitive to quite small discrepancies / calibration
> differences in a machine/coil. A difference of 10
> points doesn't represent much in terms of ground p
> hase, and ultimately, as long as the machine is co
> rrectly ground-balanced, the number it indicates i
> s not too important. It would be nice if there was
> more consistency, as comparing one site / machine
> to another would make more sense. It should be pos
> sible to force a ground balance to a length of fer
> rite rod, (which is a pretty repeatable object), a
> nd see if your two machines are 'offset' by the sa
> me amount as seen in the field.
>


> Regarding the armcup, it's probably worth buying s
> ome adhesive-backed foam sheet, cutting it to suit
> , and thickening-up your armcup padding. This sort
> of thing:
> [www.ebay.co.uk]

That is a good idea (ferrite) we will try that this coming Thursday i will take a look at that neoprene thanks for that

There's no doubt more than one way to 'skin the cat' with ferrite balancing, but here's what I would do:

The ferrite rod comes from an old AM MW / LW radio (car boot sale price 20p). They're usually 100 - 150mm long, I would cut off a 30 - 40mm long bit, a file will make a cut, and it's brittle, so should snap at the cut.

With the coil stationary, and nowhere near ground / metal, do the 'fastgrab' process, bringing the ferrite rod end-on up to about 150mm from the centre of the coil, and moving it to 300 - 400mm away. You can hold the ferrite above the coil if it's more convenient.

I can't say what an Impact will make of it, but a Fisher F75 indicates '90' , but could be 2 or 3 points off.

Pimento Wrote:
-------------------------------------------------------
> There's no doubt more than one way to 'skin the ca
> t' with ferrite balancing, but here's what I would
> do:
>
> The ferrite rod comes from an old AM MW / LW radio
> (car boot sale price 20p). They're usually 100 - 1
> 50mm long, I would cut off a 30 - 40mm long bit, a
> file will make a cut, and it's brittle, so should
> snap at the cut.
>
> With the coil stationary, and nowhere near ground
> / metal, do the 'fastgrab' process, bringing the f
> errite rod end-on up to about 150mm from the centr
> e of the coil, and moving it to 300 - 400mm away.
> You can hold the ferrite above the coil if it's mo
> re convenient.
>
> I can't say what an Impact will make of it, but a
> Fisher F75 indicates '90' , but could be 2 or 3 po
> ints off.


Just tried it with my ferrite rod it ground balances @ 88 consistently

Well that's confidence-inspiring, I guess it's worth trying at all 3 freqs, and with other coils if you have them.
Unfortunately, trying to simulate any 'real ground' is tricky, it was a project I was going to try and tackle some time.

If you are acquiring 1-bar......and.......especially 0-bars of mineralization........ the Impact (or any detector) will not Ground Balance. Here in Florida........ it is rare that I could get the Impact (or any detector) to Ground Balance........ as my dirt is like an air-test. Nothing to see/balance to.

Oh........... and go back up into the 90's with Sens.......... and see what happens to depth. (((Especially if you can get away with leaving the Grnd Bal on '90'))).

I see one of the UK testers is selling his 'Test unit, not for resale' after raving about it i'd have thought he would have kept it, bit cheeky i thought.

NASA-Tom Wrote:
-------------------------------------------------------
> If you are acquiring 1-bar......and.......especial
> ly 0-bars of mineralization........ the Impact (or
> any detector) will not Ground Balance. Here in Fl
> orida........ it is rare that I could get the Impa
> ct (or any detector) to Ground Balance........ as
> my dirt is like an air-test. Nothing to see/balanc
> e to.


I had not thought of it like Tom thanks for that.

You're welcome. Now........ go see if you can run Sens on 96 or 97........ and see (and please report) what happens to/with depth. If it's a little 'chatty/unstable' with the coil motionless......... see if stability is regained whilst sweeping coil. If you can get away with Sens on 97........ watch what happens. If not......... try a Sens of 90, 91, 92.

My analysis:

I set up using the following settings Deep 5kHz gain 94 the rest were factory defaults, tried to ground balance and found it would not so i dropped the gain to 60 and still it would not GB then i tried another spot this time it did GB,..

Being that it was 1 bar dirt, perhaps a few swings over the dirt until you got a few bars would give a better GB result. I like the DEEP 5khz setting idea. It should hit hard on deep silver. Also like you said, it will hit hard on iron falses.

...the first signal was loud and turned out to be part of a cauldron it was about 10 inches down i then got a scratchy signal with a vdi of 75 this turned out to be a pea sized musket ball at about 8 inches, i got a few more bits of lead again they were scratchy sounding.

These are some impressive and telling pieces of information. First, the cauldron(if made of iron) at that depth, would give a decent sound. I wonder what the VDI was and what would happen if you switched freqs.

Next is the pea sized musket ball. At 8 inches and a VDI of 75, the machine at 5khz, up averages(sometimes by quite a bit) with low conductors. To me, this seems normal as I saw with the Whites v3i running strictly 3khz and seeing 3 inch foil read like silver.

We crossed checked all our signals with various modes the best for us were Deep followed by D14 then D99 i then got a scratchy signal that was a George 3rd half penny at around 13 inches so the Impact has got some punch,

13 inches? thats awesome. Was the VDI close?

the Impact run fairly stable @ 5kHz but on 14 and 20 it was very chattery the impact does not like been near other detectors including other Impacts,all the signals we got today were cross checked with all 3 frequencies and they all got the signals.

I wonder what type of emi was the culprit? Did you try the freq shift?

All in all a nice little review thanks for posting!

Good info on the hunt,,,

yes Ground grab wont work in low mineral..

Keith

“I don't care that they stole my idea . . I care that they don't have any of their own”
-Nikola Tesla

The little things the impact can do are huge when you know what to do..thanks Tom

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

Beyonder-Pa Wrote:
-------------------------------------------------------
> My analysis:
>
> I set up using the following settings Deep 5kHz
> gain 94 the rest were factory defaults, tried to g
> round balance and found it would not so i dropped
> the gain to 60 and still it would not GB then i tr
> ied another spot this time it did GB,..
>
> Being that it was 1 bar dirt, perhaps a few swings
> over the dirt until you got a few bars would give
> a better GB result. I like the DEEP 5khz setting i
> dea. It should hit hard on deep silver. Also like
> you said, it will hit hard on iron falses.
>
> ...the first signal was loud and turned out to
> be part of a cauldron it was about 10 inches down
> i then got a scratchy signal with a vdi of 75 this
> turned out to be a pea sized musket ball at about
> 8 inches, i got a few more bits of lead again they
> were scratchy sounding.
>
> These are some impressive and telling pieces of in
> formation. First, the cauldron(if made of iron) at
> that depth, would give a decent sound. I wonder wh
> at the VDI was and what would happen if you switch
> ed freqs.
>
> Next is the pea sized musket ball. At 8 inches and
> a VDI of 75, the machine at 5khz, up averages(some
> times by quite a bit) with low conductors. To me,
> this seems normal as I saw with the Whites v3i run
> ning strictly 3khz and seeing 3 inch foil read lik
> e silver.
>
> We crossed checked all our signals with various
> modes the best for us were Deep followed by D14 th
> en D99 i then got a scratchy signal that was a Geo
> rge 3rd half penny at around 13 inches so the Impa
> ct has got some punch,
>
> 13 inches? thats awesome. Was the VDI close?
>
> the Impact run fairly stable @ 5kHz but on 14 a
> nd 20 it was very chattery the impact does not lik
> e been near other detectors including other Impact
> s,all the signals we got today were cross checked
> with all 3 frequencies and they all got the signal
> s.
>
> I wonder what type of emi was the culprit? Did you
> try the freq shift?
>
> All in all a nice little review thanks for posting
> !

The chatter was from many other detectors in the area (50 or so) when a few left at the end of the day the chatter was a lot less i did try the frequency shift 1 and 5 were best, the 13 inch half penny i can not remember the VDI unfortunately as i was been watched and asked questions by 3 other detectorists who were eager to see how the Impact performed they were amazed at the depth when the coin came up.

Also whats the angled plastic bit for on the coil wire ? my friends moves up and down but mine seem to be stuck solid.



Edited 1 time(s). Last edit at 04/10/2017 07:52PM by sanjuro.

I had the same problem with my racer and deus driving my impact crazy

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

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If you don’t dig it, then how are you going to know what you’re missing!
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Pimento Wrote:
-------------------------------------------------------
> Well that's confidence-inspiring, I guess it's wor
> th trying at all 3 freqs, and with other coils if
> you have them.
> Unfortunately, trying to simulate any 'real ground
> ' is tricky, it was a project I was going to try a
> nd tackle some time.


I tried both coils and all frequencies and got the results below

11x7 coil 5kHz 84
14kHz 87
20kHz 88

7.5x4 coil 5kHz 79
14kHz 86
20kHz 87 sometimes 88

I don't know what to make of that, to be honest. They seem reasonably consistent, when other people get hold of the machine, I hope they have similar figures.

I noted Sanjuro's test report where he couldn't GB the detector until the 3rd try!
Nothing new with "Makro's" as, I had a Red Racer & a Racer 2 and this was a common occurrence.
On a couple of occasions they just refused to GB at all!
Anyone else find this with their Racer's?

NASATOM answered the why in regards to the inability to ground balance in 0 or 1 bar dirt, that the machine won't ground balance if there's nothing in the dirt to ground balance to

I would think with no bars and no you can manual ground balance...not sure what number that would be...on the deus it's 90. I would think it may be the same number that shows when you turn the impact on...?

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

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If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

Another reason that you may have been unable to GB the Impact on pasture land is that the possibility of animal droppings over the years can and will affect some machines,when i use my T2 with large a large coil on some pasture sites i am also unable to GB,of course this will only be possible if the pasture site has ever been used with animal grazing.Just a possibility.

Pedlar mills Wrote:
-------------------------------------------------------
> NASATOM answered the why in regards to the inabili
> ty to ground balance in 0 or 1 bar dirt, that the
> machine won't ground balance if there's nothing in
> the dirt to ground balance to

Yes, I understand that if ground is 'neutral', then there's no 'baseline' to help establish ground condition.
The test site I was on when describing the Racer experiences has been used as a test site for years and most every detector that has a ground balance function, 'did GB as it was designed to do' including 'Deus' which at times can also not ground balance properly.
So I'm thinking the GB action in the Racer and now, the new model is flawed somewhere in the algorithm?

I've seen a FEW units that reduces Mineral so well that they don't want to ground grab..usually it's with a certain coil..

Say stock coil show 2 FE bars but then put on a different or smaller coil in same soil that reports no FE bars..

then unit's wont ground grab at times.

Mak/Noks do it and T2 a times and the Omega is really bad at not wanting to ground grab at time especially with a DD coil...the lower freq and DD almost makes it blind to mineral in say 2 bar dirt.

I'm thinking the algorithm of SOME a-like units like a LIttle Fe304 to add to the equation ??

Keith

“I don't care that they stole my idea . . I care that they don't have any of their own”
-Nikola Tesla

Junk and Disorderly Wrote:
-------------------------------------------------------
> Another reason that you may have been unable to GB
> the Impact on pasture land is that the possibility
> of animal droppings over the years can and will af
> fect some machines,when i use my T2 with large a l
> arge coil on some pasture sites i am also unable t
> o GB,of course this will only be possible if the p
> asture site has ever been used with animal grazing
> .Just a possibility.


You may be correct with the animal droppings theory the pasture site has had cows and sheep on it for many years, i have other sites which have had lots of fertiliser in the soil and that has affected the detectors ability to ground balance and also degraded the signals somewhat.