Minelab GPX4500 tips, settings, questions

[Jarrod84]

Am I right in believing that the enhance timing is an active thing that improves after a couple of swings over ground noise/hot rocks a bit like being in tracking GB.
I always run it in fixed so I'm surprised when I get a faint signal in enhance and swing back over and after a couple of passes it's gone.

 

[BigWave]

No Enhance is a timing as shown on the chart for the GPX5000 below (which also shows a timing for Fine Gold which the 4500 doesn't have). It shows the progression of timings as you move into hotter ground.
Enhance won't detect as deep as Normal in mild ground, but in hot grounds it improves the detector's performance. In the GT, I rarely get a chance to use Normal - maybe just for pin-pointing. Not sure why your GB isn't holding in Fixed, but it's not due to selecting Enhance.

 

[dam it]

What has happened to Vstrom ? have not seen him here for a while now

 

[BigWave]

Hey Fingers,
He's been busy with work and fixing a mate's shack in Moliagul.
I think he plans to take a few weeks off for detecting in the New Year.

 

[Michael1986]

I recently purchased a second hand GPX 4500 and I'm hoping to get a bit of advice on the below questions. I've only been detecting about 5-6 times so apologies if the questions are a bit silly.

What is the smallest size nugget that I should use as a test nugget before detecting? I have 4 very small pieces that are about .03 grams each that don't register with the machine when doing an air test. I'm using a 12" Evo Nugget Finder Mono Coil. Do I need a bigger test nugget or is it likely the problem is with my settings? I have tried factory default settings and some settings set by Coiltek in Maryborough and both haven't worked.

If it's the settings can you recommend a company in VIC that offers great one on one training so I can learn to use the machine a bit better? I can run the machine quietly, even in high mineralisation and pickup tiny pieces of scrap over a foot deep but not picking up the 0.03 gram pieces of gold has me worried.

Thanks guys and Merry Xmas!!

 

[HeadsUp]

Forum search for GPX 4500 settings gives these for a start , and search for posts by phasetech . Good luck

couple of quick suggestions relative to what I use:
With the 11" Elite I rarely go over 9 with Rx and 8 Stabilizer (but bump it up when I can), set frequency to between 85 and 100, use Enhance, use Quiet Audio. Should help with stability. Cheers
-
I had a look at the manual after posting the above and read enhance switch helps reduce false signals and hot rocks!!
Also had no clue about Quiet Audio and will try that next time.

Hi mate i have been running the 4500 with 11" elite I found that I can get my rx between 11 and 14 depending where I'm prospecting but my stabilizer I have backed off to between 3 and 4 also depending on the ground..I get it to run super smooth and still very sensitive with no problem picking up tiny stuff like 0.01gm ..if I run my elite with a high stabilizer I get a lot of false calls and it picks up every hot rock also when I do a manual tune I hold it in the air and slowly spin it around till I find the noisiest position and then tune it to that seems to work a treat ...

dont be too scared to dumb it down a bit, Ive often run in enhance, gain at 6 stab at 9 or 10, and found very small bits , 0.1 gm with an evo 14 x 9.

Gents remember the stabiliser [which is basically a noise filter] is full on at 1, and off at 15.
-
I didn't realise that but it makes sense that higher I go with the stabilizer the more unsettled the machine runs and it's really noticeable with the elite coils not so much with the commander coils .
-
The Gain and Stabilizer controls were set up so they both functioned the same way, i.e. lower settings is smoother/quieter, higher settings is noisier/louder.
%%%%
What are people's settings for mineralized ground which is very noisy. Canoona outside Rocky. Man it's noisy.
Enhanced, lots of ground balancing and rx/stab 7 or even 6 for me

 

[Dignit]

0.03 is a little too small for testing. You want test targets I'd say at least 0.3. I've found a few down to only 0.06 with my 4500, but plenty of 0.3's and up. A 0.5 you should find down to 6 to 8 inches.
I'll second Headsup's settings. They are what I use successfully.
Good luck

 

[Jarrod84]

No Enhance is a timing as shown on the chart for the GPX5000 below (which also shows a timing for Fine Gold which the 4500 doesn't have). It shows the progression of timings as you move into hotter ground.
Enhance won't detect as deep as Normal in mild ground, but in hot grounds it improves the detector's performance. In the GT, I rarely get a chance to use Normal - maybe just for pin-pointing. Not sure why your GB isn't holding in Fixed, but it's not due to selecting Enhance.

https://www.prospectingaustralia.com/forum/img/member-images/6786/1514178356_gpx_timings.jpg

I'm aware of what enhance is and when to use it, I just wasn't sure if it used a kind of tracking style aimed at hot rocks etc as I have definitely noticed a signal change/fade away when using it in fixed.
I'll take more notice next time I find one and have a go in other timings to see if I can get the same thing to happen.

 

[Jarrod84]

.03 is too small.

A shotgun pellet is a good small test target, then a .22 bullet, you're always bound to find a few while you're out so you can always pop them back in the hole and have a play with the settings. No need to buy gold if you haven't found any yet.

My biggest advice with settings is don't change a setting until you understand why you're changing it and what effect it should have.

 

[10fp]

Re Hot ground and Hot rocks, I was watching BugWiskers with the QED and when he gets some hot ground he just raises or lowers the GB a few clicks and if the noise dissappears walks on , SO its got me wondering if there`s a similar way to do that with the 4500 eg. press the GB button and raise the coil a few inches and let it off then see if the signal is still there . Anyone hav their quick way of determining Hot ground without digging

Some reading on here 2 years ago i think there was talk of switching Timings or they had a set up in Special that used to quickly check for hot ground noise with out digging

Nenad ??

i think that was a QED feature that really impressed me So thats my next challenge to work out a quick proceedure for that with the 4500

cheers Dave

 

[nuggetino]

No Enhance is a timing as shown on the chart for the GPX5000 below (which also shows a timing for Fine Gold which the 4500 doesn't have). It shows the progression of timings as you move into hotter ground.
Enhance won't detect as deep as Normal in mild ground, but in hot grounds it improves the detector's performance. In the GT, I rarely get a chance to use Normal - maybe just for pin-pointing. Not sure why your GB isn't holding in Fixed, but it's not due to selecting Enhance.

https://www.prospectingaustralia.com/forum/img/member-images/6786/1514178356_gpx_timings.jpg

I haven't found a situation where the hot ground timings outperformed normal mode. Enhance loses out drastically on depth in moderate ground and on very hot ground dropping the RX gain sufficiently (6 or less) still sees more depth than running the hot timings in my experience. There may be some ground I haven't encountered that could give the hot timings an edge but I have not found it in WA or the GT

 

[Jarrod84]

Re Hot ground and Hot rocks, I was watching BugWiskers with the QED and when he gets some hot ground he just raises or lowers the GB a few clicks and if the noise dissappears walks on , SO its got me wondering if there`s a similar way to do that with the 4500 eg. press the GB button and raise the coil a few inches and let it off then see if the signal is still there . Anyone hav their quick way of determining Hot ground without digging

Some reading on here 2 years ago i think there was talk of switching Timings or they had a set up in Special that used to quickly check for hot ground noise with out digging

Nenad ??

i think that was a QED feature that really impressed me So thats my next challenge to work out a quick proceedure for that with the 4500

cheers Dave

This is how I have been doing it.
If you're in enhance and get an ok signal but it sounds a bit broad or just not 100% then flick to normal timings, if it's ground noise the signal will now boom, if it still sounds like an ok signal then investigate further.
If you're in normal and get the same faint signal then take few inches off until the signal is decent then flick to enhance, if it's gone it's ground noise, if there is any target like signal, investigate further.
You will prob need to gb each timing change.
The QED way is OK but I've found enhance on the 4500 to be far superior in telling me what's going on.

 

[YellowFever]

GPX loves lead. Big or fly poo. I have around 50kg of sub gram and then point gram pieces...zed loves lead...regardless of size (although it does have an appetite for minute lead.
Sdc i cant comment on, Zed and gpx i can...
Zed is a beautiful machine to operate.....but a 4500 or a 5000 with a 14" elite or equivalent 15" Evo will do as good and even better given the right circumstances. Just my testing and experience.
Cheers
YF

 

[YellowFever]

If you know how to tune your GPX with the standard 11" commander mono then you already have a serious A grade piece of gear.
The key is to know your equipment before you start becoming a coil king.

 

[YellowFever]

Enhance can and will outperform normal mode given the right ground conditions.
Normal is simply a maximum peak of optimisation of the gpx's settings so it can run at its peak on "allowable ground conditions ".

If you detect in hot ground consistently (ie the GT) more than likely you will NEVER get to run in normal unless your detecting in a mild loamy type area that is almost unheard of anywhere in VIC GT let alone the rest of Aus's goldfields.
Normal mode is not even a consideration in 99.9% of the VIC GT.
Even at a rx gain of 6 or below in normal you can do A LOT BETTER in enhance with bumped up settings to suit.
What may work for your area probably wont work in ours.

 

[Redfin]

The other week I was in reasonably hot ground, just north of Dunolly and picked up 9 bits totalling just shy of 3 grams.
I was using factory presets in enhance, with a NF 14x9 evo.
On each target, which varied in size and depth, the deepest being about 6 inches, I changed settings before the scrape/dig, to check the response.
On ALL targets, I turned the
Stabliser [which is a noise filter] full on [ a setting of 1]
and the RX gain right down to 3.
and still had a clear "dig me signal" on each bit.
the 45 is a very good machine.
The 5000 was in a Minelab getting a tuneup, next time will check that as well.

ever since we have had the 45 and 5k, I have never been on ground capable of running in normal.

as for ground noise, Stoppsy sums it up pretty well here
https://www.youtube.com/watch?v=M-mtfCM7teg&t=7s

 

[Moneybox]

If you know how to tune your GPX with the standard 11" commander mono then you already have a serious A grade piece of gear.
The key is to know your equipment before you start becoming a coil king.

Yes I spent our first season out there using the Coiltek 14" Elite with great success. I tried the 11"DD a couple of times but overall stuck with one coil because I was still working out how to operate the GPX4500.

This year I went armed with a larger 19" NF Mono and a smaller 11" Mono but soon realised that time spent swapping between coils was mostly a waste of time. I'd chosen the 19" NF because I had a couple of favorite spots that had produced good sized nuggets at the limit of the 4500's depth using the 14" Elite. I was hoping there were more large nuggets waiting for me down deeper. I never stirred up one in the half dozen places where I'd pulled good gold from before. I felt sure I'd get one good nugget to cover the $600 I spent on this coil.

Late last season I borrowed an old 11" Coiltek Elite. It drove me mad with noise but when I managed to eventually ground balance it it found some tiny SDC type gold. This year I decided a new 11" Mono should give the SDC a run for it's money on a few patches of fine gold we know about. How wrong I was. The new spiral wound mono was sensitive alright but was so noisy in hot ground it was a waste of energy. What it did though was convert me to using the light weight coil.

I ended up fully convinced that the original Commander 11" Mono coil was the best coil in my kit. It stayed glued to my GPX4500 and found most of our gold. The new GPX4500 that we purchased before going away ended up being a GPX5000 once it was unpacked so I used it to swap coils when I felt like it. I thought the extra settings on the 5000 might have helped but in the areas where we travelled I couldn't see any advantage in the $2000 extra expense. I'm no longer convinced that the fancy new coils are worth the money spent on them. Perhaps in mild soil conditions they may produce more gold but it the hot (40 Deg +) temperatures in the ironstone country we walked over, we surely missed more gold using a noisy chattering coil than the smooth quite running Commander.

 

[PhaseTech]

Re Hot ground and Hot rocks, I was watching BugWiskers with the QED and when he gets some hot ground he just raises or lowers the GB a few clicks and if the noise dissappears walks on , SO its got me wondering if there`s a similar way to do that with the 4500 eg. press the GB button and raise the coil a few inches and let it off then see if the signal is still there . Anyone hav their quick way of determining Hot ground without digging

Some reading on here 2 years ago i think there was talk of switching Timings or they had a set up in Special that used to quickly check for hot ground noise with out digging

Nenad ??

i think that was a QED feature that really impressed me So thats my next challenge to work out a quick proceedure for that with the 4500

cheers Dave

No, don't think it was me. I use a "hot" Custom mode that I use for Auto Tuning when EMI is bad.

For checking a possible hot ground spot, (assuming Im running in Fixed GB), I will press the green quick-trak button, and sweep the coil around the target area - this is achieving an average ground balance of the surrounding ground. Then release the button and go over the target area again; 9 times out of 10 if the signal was caused by ground noise it will now be gone, or significantly reduced. If the signal was from a genuine metal object, the signal will still be there or more obvious.

 

[BigWave]

Well said MB. I'm switching back to my old Commander 11"mono more often these days. I was known for only using it, but seem to have lost my way.

 

[ashleypicken]

Gday all,
After some advice on the best coil to buy for my gpx 4500.
Cheers :Y: