Minelab GPX4500 tips, settings, questions

[Guest]

Otto fiberglass shafts are awesome, been using the same one since my gp extreme.

And a big thumbs up for the cable guard. Not a fan of the clips though, they flick off and fly into the scrub.

Possibly note for everyone but i just use some irrigation clips to clamp the cable to the shaft. Bought them from bunnings for around 50 cents each. Give them a twist to undo when changing over coils.

 

[Nightjar]

Nightjar,
Did you notice any difference in performance.?
What is the main reason and difference you found.
Thanks for your comments.

Not wanting to bore you with old posts but this subject goes back to the SD 2100. I had a liking for the 18" Mono however the detector was noisy and finally I narrowed it down to when the coil was swung to the left the interference was at it's worse. Had a pick swinging off my left hip and when I removed it problem solved.
Began thinking if the pick was interfering why wouldn't the aluminium shaft interfere when it flexes.
Fibreglass top and bottom shafts and pick carried on my chest from that period on.
Lost count of prospectors who insinuated that I couldn't swing a mono on the ground we were on. Some actually slipped the harness on and tried for themselves. That 2100 used to talk to me however technology did go forward and began upgrading when the 3500, now swing a 4500.
To this day am amazed how many here in WA carry a large pick on their hip or an even larger one balancing on their shoulder when 90% of the gold is within the first 100mm.

 

[Blueboy]

As an aside to the gold if you find a nice spot in the bush for relics the 4500 Iron discrim works really well with the DD coil... most of the trash from back in the day was iron so it's a good goldfields relic machine to boot.
Bought a Sadie coil, looking forward to giving it a go in the coming weeks.

 

[Dignit]

When I first got my 4500 in Sept last year, nearly one year now, I had a training day with Gold Prospecting Australia. They suggested the following settings irrespective of coil, but this was before the new flat wind coils came out.
Deep, Enhanced, Quiet Audio, Auto Tune, V.slow to slow Motion, Audio Tone about 38, Rx as high as possible (just as threshold is unstable), use Stabilizer to quieten threshold, Signal 17, Target Volume 16 with remote speaker, Fixed, Mono (that's all I use for gold), Normal.
I've often thought Quiet Audio counter acts for the Deep setting, and wondered what the real technical difference is. My thought is that Deep punches deeper and thus it can cause more noise/instability but Quiet smooths that out and makes signals a little quieter. Perhaps someone can explain this in more technical detail.
I have used these setting with reasonable success, even with the new flat wind more sensitive coils.

In my search for improved performance I recently returned to the instruction manual and have picked up on a few finer points of adjustment, as follows:
Auto tune in fast motion then change to v.slow or slow.
Manual Tune to high frequency can be slightly more sensitive to smaller shallow gold.
Manual Tune to low frequency can give a little more depth to larger targets.
V.slow motion will allow for maximum stability.
Rx at 8 is factory preset ....... I think I push Rx too high at times, and wonder why I have noise problems. So have been trying to give in to this and wind the Rx back so I have better stability. I find early mornings and evenings I can wind the Rx right up to 13 without a problem. Instructions say a lower Rx is preferable for noisy conditions or high interference areas, and be prepared to reduce Rx if the background threshold is erratic.
Quite gives the most reduction of both ground noise and interference.
A high Audio Tone may help identify small targets from ground signals.
A low Audio Tone may allow deep targets to stand out.
Stabilizer one number below where threshold chatters.
In highly mineralised ground high Signal may make the detector appear noisy.
Target Volume can also be used to reduce or smooth out ground noise in highly mineralised soils.

All food for thought and trial.

Cheers

 

[mbasko]

I've often thought Quiet Audio counter acts for the Deep setting,

When you select the Deep search mode the audio should be preset at Deep Audio. Once you change into Quiet Audio (+ change other preset settings) you are no longer in the Deep search mode as per the presets - you are in your own customised version of it. Don't get too caught up on the search mode - they are only presets of suggested settings to suit certain scenarios & most just change them to suit current conditions or personal preference.
Quiet will make signals fainter but also reduces ground noise & interference.
Getting settings off a trainer is fine, even better if they're working for you, but the advantage of the GPX's is in the available adjustment to suit different conditions. There really is no one lot of settings to suit all IMO

 

[Ridge Runner]

I would have thought that the 705 would have been a great machine in it's own right because when the junk is too thick then the 705 could turn the day around,

In a perfect world a GPX, SDC, and a Lower KHz VLF and a High KHz VLF, would cover all bases, It's always a good plan to try the VLF first just to see what the ground is doing and what junk is buried there beat the heck out of digging tons of junk just to find out you have found a rubbish dump,

I did that Once and now I always check the place out with a VLF before I use anything else,

John

 

[tigersnake]

I have just paid for my gpx4500 I'm hoping I can work it out when it turns up. Very excited.

 

[Sparra]

Does anyone know of anyone on the South Coast that does beginner courses for the 4500 or is it just a matter of getting out there and having a go..

Cheers...

 

[davent]

Get out there and use it on factory settings.
Play around with the stabiliser and RX gain. Also threshold and target volume.

G ain

S tabiliser

T arget V0olume/Theshold.

I was new to the GPX, and had no one to give me a hand except the good people here. Best way is hours on the machine.

 

[Tathradj]

Look forwards to meeting up some time Sparra,
When I get back from this Holiday I
will look you up.

 

[jamie]

as davent said, use the factory pre set at first to get you up and running and some time on the machine then play with settings once you are a bit more familiar with it, when i got my 4500 i used factory pre set, 11" dd and got a 1.3gm nugget first outing with it, great machine and time with it will only make it better, best of luck

 

[jamie]

Does anyone know of anyone on the South Coast that does beginner courses for the 4500 or is it just a matter of getting out there and having a go..

Cheers...

Pretty much how I am learning so far mate, my training day got canned so still waiting to do it at a later date, sent you a PM mate

 

[Tracker]

So, I've read various comments across the threads, but in summary, is the collective impression of the GPX 4500, that it's 'almost' as good as the 5000 ....
To the point, that's there's not much benefit to be gained in the almost $2,000. price difference ??

 

[jamie]

Tracker when i was going to buy a detector i had my mind made up on the 5000, then got into a discussion with a well known and highly respected prospector and he said to me that in hind sight he wouldnt have bothered 'upgrading' to the 5000 if he knew then what he does now, i went with the 4500 after thinking about what he said and compromising with the wife, the 4500 is a hugely capable machine and finds gold but if $2000 difference isnt going to brake you the 5000 would be the pick i guess if a 7000 is out of the question, my thoughts anyway

 

[Braggy]

Thanks guys for the advice about the factory presets on my 4500, that's where I'll start.
One more question, any recommendation on a speaker ( brands and where I can purchase) that I can just plug into the li-ion battery and mount on my harness as headphones tend to make me a little claustrophobic.

 

[old hand]

Braggy most detector shops sell speakers Bendigo should have them , once you get a speaker get a piece of 2 inch pipe cut it on a angle and glue it onto the front of the speaker by doing this it directs the sound up at your ears and not out in front of you regards john

 

[old hand]

This is what I talking about

 

[Nugget]

Thanks guys for the advice about the factory presets on my 4500, that's where I'll start.
One more question, any recommendation on a speaker ( brands and where I can purchase) that I can just plug into the li-ion battery and mount on my harness as headphones tend to make me a little claustrophobic.

I feel the same, so I use one of these from Miners Den http://www.minersden.com.au/low-feedback-metal-detector-speaker/, it's nice and loud and doesn't distort on full blast.

 

[Braggy]

Thanks Old Hand appreciate the reply
Regards Braggy

 

[Braggy]

Thanks Nugget
I've checked it out on your link, looks just like what I need, will order online tonight.