Iron Discrimination With GPX

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Has anyone got advice on settings for iron discrimination with GPX 5000 smilemaker ?

i went to a mates property near Goulburn on the weekend that has no known history for gold on the maps i could find, but i was willing to give it a crack from a standpoint of pure explorative optimism.
some places were impossible to detect due to the high cencentration of ironstone and i didnt learn yet how to use the iron discrimination on my GPX smilemaker .

I was naughty and only spent 2 hours reading the manual so far before just jumping in to the field for some exploration

found lots of nails , bullets and hotrocks , dollied up some interesting hotrocks and found granules of a heavy white metal that i will smelt and try to determine what it is from a specific gravity test once i have a blob of the stuff.

I will be going to the next available training day at Hill End but wondered if any of you guys / ladies have suggestions for your settings ?


thankyou muchly
 
Hey Headsup, which coil were you using, Iron Discrim will only work with a DD coil, I usually set it at about 4 or 5 when beach detecting. On the goldfields I really only use a monoloop and dig every target. You need to try a few different settings, if you were in Normal soil timing you might want to try Enhance, Fine Gold or Sensitive Smooth. Maybe even High Mineral search mode also.
 
Heatho said:
Hey Headsup, which coil were you using, Iron Discrim will only work with a DD coil, I usually set it at about 4 or 5 when beach detecting. On the goldfields I really only use a monoloop and dig every target. You need to try a few different settings, if you were in Normal soil timing you might want to try Enhance, Fine Gold or Sensitive Smooth. Maybe even High Mineral search mode also.

thankyou

yes i was using the DD in enhance mode but i had iron rejection set between 10 - 16 from memory , i was in ironstone that was concentrated enough to stick to a magnet in places.

I also used the mono but although the signals were clearer with less noise in between the ironstone i simply couldnt get past the ironstone orchestra where it was present.

i can see myself carrying both coils for a while

i dont mind preparing myself to spend at least 3 months getting to understand this thing properly

its just a learning curve

thanks and best wishes
 
Yeah I ahgree, hell of a lot to learn, sounds like a very heavy mineralisation, maybe some guys with more experience in these conditions can help out.

Did you do an autotune and get a good ground balance, sounds like it was'nt ground balanced correctly to me or maybe even RF noise from power lines. Were all the signals repeatable or false signals?
 
I did autotune each time I switched it on and each time I changed coils but I just found in the manual that tracking mode is not recommended for iron rejection . I should have used fixed... that explains part of my confusement .

Back to la manual. :/
 
Yeah that may just be it, I have not used the tracking function yet, always fixed. Hope that sorts it out. Have to ground balance pretty often though to keep them smooth in some places.
 
hello headsup
the gpx 5000 should run quiet with a mono in fine gold and enhance in the thickest of ironstone areas, so i'm thinking maybe you had the gain too high (try around 12) or your target volume too high (try around 16)
do you realise if you want to run a fine gold with a mono, you have to have the switch on the front set to special?
If the ground is so bad that you can't settle down the machine, you can run a mono in smooth.
In smooth (special on front and smooth in back)you will lose depth but you will not be getting false signals all the time, it is pretty rare to need smooth though.
Normally you can get the 5000 to run great in fine gold or enhance in some of the worst ground around, I always run in fixed and balance all the time.
iron discrimination is for rejecting iron targets with a dd coil, not for rejecting ironstone laden ground.
regards trashmagnet
 
trashmagnet said:
hello headsup
the gpx 5000 should run quiet with a mono in fine gold and enhance in the thickest of ironstone areas, so i'm thinking maybe you had the gain too high (try around 12) or your target volume too high (try around 16)
do you realise if you want to run a fine gold with a mono, you have to have the switch on the front set to special?
If the ground is so bad that you can't settle down the machine, you can run a mono in smooth.
In smooth (special on front and smooth in back)you will lose depth but you will not be getting false signals all the time, it is pretty rare to need smooth though.
Normally you can get the 5000 to run great in fine gold or enhance in some of the worst ground around, I always run in fixed and balance all the time.
iron discrimination is for rejecting iron targets with a dd coil, not for rejecting ironstone laden ground.
regards trashmagnet


thankyou . printing out your post so i can take it out with me next time i go

I have been waiting for Minelab to contact me about my Hill End training day . . . ? might have to chase them up on that front 8)
 
Agree with trashmagnet & yes you will learn that at the training day. It is a pretty full on day but very helpful. Especially for people that don't read the manual (like my hubby) Lol :)
 
froghoppers said:
Agree with trashmagnet & yes you will learn that at the training day. It is a pretty full on day but very helpful. Especially for people that don't read the manual (like my hubby) Lol :)

LOL . yeah well i dont blame him for not reading the manual

Have you seen how many words are in those things ? :eek:

Seriously i think i read so much at work that the last thing i want to do is read a manual , or maybe there is just some kind of deepseated genealogical aversion to it way way way down deep in our DNA :8
 
your welcome headsup
to book for the training day you need to ring minelab and tell them what state you wish to do it in
and they will tell you what date.
regards trashmagnet
 
trashmagnet said:
your welcome headsup
to book for the training day you need to ring minelab and tell them what state you wish to do it in
and they will tell you what date.
regards trashmagnet

i rang up miners den the day after i bought the machine and asked when i could be booked in for the course

they reckoned Minelab 'have my details and would be contacting me' :/

it didnt sound right when i heard that but i shall be phoning ML myself to get that cracking
 
Been doing the usual research with my new GPX 4500 and am still a little puzzled with the Iron Discrimination using a DD coil.

https://www.prospectingaustralia.com/forum/viewtopic.php?id=2181

I Know Headsup started this conversation a while ago, just want to revisit. Most people also say use a Mono coil in most situations. U cant discriminate with a Mono.

Almost every person says "don't use it" (discrimination), and ive heard people say they've dug iron targets then found gold underneath.....

Watched Stinky Pete http://www.detech-metaldetectorsaustralia.com.au/#!blog/c5oe using iron reject and finding a 3 grammer

So I guess I feel I'm getting mixed messages. With the VLF the iron mask helps in trashy areas to avoid digging 50 holes and finding 49 bits of nail and horseshoes etc, however it seems a big no no to discriminate with the GPX.

Can anyone shed some light on the discrimination, when to use, when not to use? I understand that the more holes I dig, the better chance of finding gold....but on the flip side......passing by iron targets may make me get to the gold faster even if I miss a few, given gold is usually not alone.

Any rational feedback appreciated, I still have my GPX training wheels on but would love to hear some opinions other than everyone says don't do it, so don't do it....if that makes sense!
 
ok I get that, so who uses it and why and does it work and why does everyone say don't use it! :lol: :lol:
 
I use DD coils on my sd2200d and I use the discriminator on screamers- It is very accurate and I use it for this purpose only (big close targets)
Twapster, you will find that unless you're super lucky most gold targets will be faint and alot of the time small pieces of steel will also sound quite similar- the discriminator can't get enough info from these small trash targets and you will have to dig them.
After a while you will know by the sound your machine makes what shoe tacks, 22 shells, small wire, lead shot and if you're lucky nuggets all sound like.
 
Reeks said:
I use DD coils on my sd2200d and I use the discriminator on screamers- It is very accurate and I use it for this purpose only (big close targets)
Twapster, you will find that unless you're super lucky most gold targets will be faint and alot of the time small pieces of steel will also sound quite similar- the discriminator can't get enough info from these small trash targets and you will have to dig them.
After a while you will know by the sound your machine makes what shoe tacks, 22 shells, small wire, lead shot and if you're lucky nuggets all sound like.

Later model PI machines (like your 4500) are much more stable and rely less on the use of DD coils. GPX series were designed from the (mono) coil up and as such mono's run as smooth as DD's but have a more sensitive response to targets.

As for knowing what sounds like what...i refute that with my own experience.

eg1; It is stated when you hear a double response over a single swing that it will be a nail or long piece of wire. I hit such a signal one day and dug it anyway (using a mono coil) and lo and behold a 4.5cm long 7.4gm (1/4 of an Oz nearly) chunk of gold. (have a pic but can't seem to get them up on here so if ya wanna see it, PM me your email and i'll show the pic).

eg2; I thought i had "sounds" down to a T with my GPX 4K & 11" mono. Swung over what sounded to my "trained" ear as a piece of junk, dug down 7" and picked out a 2.1gm nugget. I now carry this with me to remind me of just how much i "don't know" and to dig everything.

Now ordinarily, based on my "educated" ear, i would normally have walked past these target responses, but due to being in the habit of dig everything, i ended up being pleasantly surprised.

No matter the operator, or how long they have been in the game, i defy anyones claim of "knowing" what gold sounds like & being correct 100% of the time. I have seen a 7 Oz nugget blanking (overloading)on a discriminater set up detector and since that day (early in my beginnings) i have only used mono coils....and dig everything. You won't know what the target is until you dig it, and gold can be found under the junk.

Do i dig i LOT of junk?.... Hell yeah, but i reckon i leave behind a lot less gold in my journey than others who believe they know what GOLD sounds like. I also tend NOT to walk over Gold to get to Gold, as the saying goes.

Perhaps the targets above are exactly examples of this and i found the gold others left behind in the belief it was "junk"?

Just treat each outing as a treasure hunt and be pleasantly surpised by what you are lucky enough to find imo. Gold becomes a bonus, enjoy being out in nature and part of something more grand than you or I.

Cheers
 
Imo with no knowledge on its use for gold but the above posts certainly give me an answer, I used disc. with my old vlfs to hide iron signals as I wasn't interested in relics and large steel bolts and nails anymore and only wanted coin an jewellery.

Using disc. on that detetector, at certain incriments, it would null out a metal of that number. For example if I had disc. on and set to 2 it would detect most metals.. turning it up to 5 removed iron signals and some pull tabs. Going further to 7 and 8 was certain solid alloy, lead, silver and copper which let me detect the noises that 'looked' like a coin positioned either flat or upright and dodge anything large which was most likely alloy cans or foil.

You loose depth using discrim I'm sure you know, in saying that though, i was set on disc and dug out a massive old train lead acid battery deposit, but the size probably gave away its 1m depth anyway.. I still have lots to learn on coils and detecting though but that's my two cents worth on discrimination :p

I don't know if the Eureka Gold which I've just gained can discriminate that way, the only signal I'm getting with it is blanking over iron but stops the signal for at least 1 second so it misses ground when in that mode..ill need to ask about too
 
AR... that just goes to show, horses for courses, and in your situation it served you well... but Gold is sneaky like that and can have different sounds due to many factors including size, the type of gold it is (nuggetty/specie/crystal), orientation in the ground, the type of ground it's in, and even weather (hot/cold/wet/dry).

Oh...and i'm led to believe that pull tabs and Gold have very close ID #'s so you still can't be sure you have got it right all the time imo.

The 2.1 gm nugget i mentioned above is really light for it's size as it only feels like maybe a 1 grammer at best and i took a few moments to even find it in the spoils.

Gold is where ya find it (and can't that surprise us) and each individual piece also has it's own sound, but i don't believe an identifiable one that can be guaranteed of success 100% of the time.

Gypsy
 

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