Testing your detector on targets

Go down

Testing your detector on targets Empty Testing your detector on targets

Post  johnf on Fri Feb 26, 2010 5:55 pm

Hi members, I,m wanting to use 3 or 4 different size practise targets at various depths on aregular basis whilst in the goldfields so i become accustomed to the different sound of the signals. I do take one small piece of gold with me, but don,t want to take too many pieces.(hard work getting them could,nt bear to loose them)!! I do realise the signals would be slightly different than un-earthed gold. I thought lead was the closest signal to gold but have recently read a technical article saying aluminium was more similar in some respects. Fair chance I,ve misunderstood but am still wondering which metal to go with.can anyone give me any advice please? Thanks, johnf

johnf
Contributor
Contributor

Number of posts : 22
Registration date : 2009-02-01

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  Guest on Fri Feb 26, 2010 8:06 pm

hi
 someone please correct me if i am wrong
 lead has 82 electrons per atom and gold has 79 electrons per atom,and on the atomic scale gold has a atomic mass of 196.966569 g/mol and lead has an atomic mass of 207.2 g/mol
 what that means is a detector cannot tell the difference between gold and lead.if you are detecting in an area where you are digging up bullets,you don`t have to take any test pieces.you can use the bullets that you find as test pieces.  i`ve dug some deep bullets that i was convinced HAD to be gold because of their depth


Last edited by day one on Sat Feb 18, 2017 7:57 pm; edited 1 time in total

Guest
Guest


Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  MS on Fri Feb 26, 2010 8:59 pm

I agree , there is no sound difference between gold and lead
That's all I use for testing.
Cheers Mark
MS
MS
Contributor Plus
Contributor Plus

Number of posts : 792
Age : 53
Registration date : 2009-03-17

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  hunter2003 on Fri Feb 26, 2010 9:14 pm

johnf, hope you don't mind me jumping onto your query,

for those of knowledge, if I was to use three different sized fishing sinkers, pushed into the side of a bank,
and then detected from above, would this give as good as could hope to get, an indication of sound, and depth
capabilities of different coils?

looking forward to your advice,

cheers,

h2k3

hunter2003
Contributor
Contributor

Number of posts : 29
Registration date : 2010-01-30

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  nero_design on Fri Feb 26, 2010 9:21 pm

Daywun is quite right... and Aluminium has just 13 electrons. I certainly can't tell the difference between Gold & Lead so all those bullets you dig prove that the ground there where you found them was not reliably worked over. That's always a good sign!
____________________________________________________

Gold has a density of 19.3 g/cc, whereas Lead is just 11.35 g/cc by comparison.
On a level of density, Aluminium (Aluminum/Alumium) is a lowly 2.7 g/cc!
____________________________________________________

Lead and Aluminium are identical when it comes to Electric Dipole Polariz @ 6.8 10-24 cc
...Gold is 5.8 10-24 cc.
____________________________________________________

Lead and Gold are far more closely associated when it comes to Susceptibility @ -23 microGauss (Lead) and -28 microGauss (Gold).... but Aluminium is 16.5 microGauss.
____________________________________________________

Resistivity puts Aluminium ahead at 26.5 nanoOhm meter - compared to 208 nanoOhm meter (Lead) and 22.14 nanoOhm meter (Gold)
____________________________________________________

Aluminium is more easily discriminated against than lead so you can cancel out ring-pull tabs on machines that offer reasonable discrimination. The Gold-machines (eg Pulse Induction detectors) can't discriminate nearly as reliably so Lead and Gold almost always sound exactly the same and there's no machine today that can discriminate reliably between the two. Don't confuse lead foil with aluminium foil as I'm certain the two offer different results. You can sometimes find lead foil in the ground near old camp sites but people don't use it for cooking because it's toxic.

Remember to try to avoid disturbing the surface minerals when conducting tests with buried targets! You can sort of get away with it by shoving the target into the ground at an angle so that the surface soil is not disturbed. On discovering a new target, one of the first things a detectorist will do is scrape away the topsoil to remove any debris and also to remove the minerals that sit on the very surface. If the target is still there afterward, then the signal is usually clearer and the target may indeed be worth digging if it wasn't scraped away when the surface was purged.

If you are worried about losing your gold sample, (be sure it's at least a gram or more in size if possible)... tie some dental floss to it (it's hard to snap this material) if the shape allows you to. That way you can retrieve it more reliably when digging it out again.

Cheers,

Marco
nero_design
nero_design
Contributor Plus
Contributor Plus

Number of posts : 2025
Registration date : 2008-11-18

Back to top Go down

Testing your detector on targets Empty target material

Post  johnf on Fri Feb 26, 2010 11:13 pm

Hi members, thanks to all for your prompt and helpful replies.Thinking back,Marco,the lead bullet signal does give a blood rush like gold and like you say,others have missed it and at least you know the detector is still functioning properly. regards johnf

johnf
Contributor
Contributor

Number of posts : 22
Registration date : 2009-02-01

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  Gold Roo on Fri Feb 26, 2010 11:23 pm

For a test target I use a small flat nugget (0.5g) wrapped with a bit of nylon cord, off sunglass holders and then used heat shrink tube (shrunk on) to keep it all secure.

Cheers Graham
Gold Roo
Gold Roo
New Poster
New Poster

Number of posts : 6
Registration date : 2010-02-03

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  mallee00 on Sat Feb 27, 2010 12:03 am

Easiest way to find your small test pieces is to fold a length of insulation tape over it, i use a .2 as a test piece and it is folded in a 1" bit of red tape. Sticks out like the proverbial. mallee00 and the mutt

mallee00
Contributor Plus
Contributor Plus

Number of posts : 208
Registration date : 2008-10-21

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  deutran on Sat Feb 27, 2010 1:08 am

Try a threepence,sixpence,shilling and a 2 bob the silver ones before 45',great conductivety like gold and good surface area.Lead is good though cause if you can pick that up you'll definitely get the yellow stuff.
deutran
deutran
Contributor Plus
Contributor Plus

Number of posts : 1667
Age : 55
Registration date : 2009-09-26

Back to top Go down

Testing your detector on targets Empty Re: Testing your detector on targets

Post  Guest on Sat Feb 27, 2010 8:54 am

Gday


For testing purposes I have always used lead if I wanted to set up a test bed somewhere that you can leave them there for next time, and not be too concerned if someone else comes along and finds them.

There are many variables when it comes to the way that your detector will react to a target, nuggets are rarely perfectly round or flat or square, some can be reasonably close but for the best part they have many different shapes, sizes and textures that will also effect the signal you will recieve.

Aluminium I dont feel is a good test medium as it is not close to gold or lead in its composition and would not give a true mellow signal like what gold and lead does, anybody who detects for coins on a beach for instance would tell you how well $1 and $2 coins stand out even when deeply buried, the reason is there aluminium alloy content.

The other thing is that you are training yourself (your ears) to recognise the mellow and sometimes barely audible sounds that that some nuggets will make, this is more important if you are looking for deeply buried pieces, but will also help you locate those odd shaped and iffy signal type pieces that are shallow but have been missed due to the signal response being so vague, this is particularly true of specimen nuggets.

I have found many buried lead pieces that have been at varying depths and have had all the features of being a gold nugget, and you are still convinced until you wipe off the dirt, these pieces have varied in size from sub gram pieces to one that was about 20+ grams, coarse and rough in appearance tooTesting your detector on targets Icon_mad .

I have never been so convinced with a ring pull or screw cap lid that I had to clean the dirt off to decide what it is, with practice you can tell the difference between the bright sharp sound of a ring pull over the dull and mellow signal of a nugget, in the goldfields there are not that many aluminiun targets, well not as many as there are at a beach for instance, sometimes you will get on to a spot that was worked in the eighties and you will find a heap of the old style long ringpulls and sometimes they are buried, but lead, thats another story as there has been lead shot about the place for a couple of hundred years so there are many thousands of buried lead targets to be found, from musket balls to bird shot.

The one thing that I have noticed with doing target test signals is that you dont have to bury a lead target too far down before it starts to take on the signal characteristics of a gold target, where any other medium will give a better signal response at the same depth, try it and see, once you have trained yourself to recognise these mellow signals and have found gold pieces you will not forget what they sound like and the descriminator in your head will make up its mind what it is before you even have it out of the ground, either right or wrong, experienced detectorists will know what I am saying here.

If you are able to locate and recognise the signals you are getting from lead targets then there is no reason that you wont find gold if its there, like I said once you have it in your head then you will have it for good, concentrate on the vague and iffy signals, dig everything you hear and your finds will definately increase.


cheers

stayyerAU

Guest
Guest


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum