Input wanted from GPX and GPZ owners

bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
Hi everyone --

A few weeks ago, I purchased a used GPX4500. Because of a few, minor missing parts, I wasn't able to test it out stock before I sent it to Woody for his mods. I also ordered his signal booster/enhancer and compact batteries. I've got the machine back now, and trying to understand how to use it, and all the settings. I've got hundreds of hours under my belt with VLFs, but, as you know, this is COMPLETELY different. To say I'm a bit overwhelmed would be putting it mildly! I've read through the manual a few times, watched the DVD, and copied as much additional info off the web as I can find, including Steve H's instructions.

Anyway, if I could get a bit of input on the depth I'm getting on an air test, that would be helpful in at least letting me know I'm on the right track. With a Jefferson nickel and a Coiltek Elite 18" mono coil, I'm getting 24" with it basically on Deep and Normal. How does that compare with what you all can get with a large coil?

Also, I'm limited right now to testing in my yard as I learn how to use it. I've got nearby power lines giving me fits. In one direction they're about 50 yards away, and the other direction, about 100 yards. I can get it tuned and get repeatable signals, but what I'm wondering is if the electrical interference might actually overwhelm the potential of the circuitry to be as sensitive as it normally could be? I know it makes detecting faint signals challenging just because of the audio problem, but is there also a circuitry issue?

Thanks loads!
 
Upvote 1

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Hi everyone --

A few weeks ago, I purchased a used GPX4500. Because of a few, minor missing parts, I wasn't able to test it out stock before I sent it to Woody for his mods. I also ordered his signal booster/enhancer and compact batteries. I've got the machine back now, and trying to understand how to use it, and all the settings. I've got hundreds of hours under my belt with VLFs, but, as you know, this is COMPLETELY different. To say I'm a bit overwhelmed would be putting it mildly! I've read through the manual a few times, watched the DVD, and copied as much additional info off the web as I can find, including Steve H's instructions.

Anyway, if I could get a bit of input on the depth I'm getting on an air test, that would be helpful in at least letting me know I'm on the right track. With a Jefferson nickel and a Coiltek Elite 18" mono coil, I'm getting 24" with it basically on Deep and Normal. How does that compare with what you all can get with a large coil?

Also, I'm limited right now to testing in my yard as I learn how to use it. I've got nearby power lines giving me fits. In one direction they're about 50 yards away, and the other direction, about 100 yards. I can get it tuned and get repeatable signals, but what I'm wondering is if the electrical interference might actually overwhelm the potential of the circuitry to be as sensitive as it normally could be? I know it makes detecting faint signals challenging just because of the audio problem, but is there also a circuitry issue?

Thanks loads!
Hi. Im in Oz and used the 4500 as well as numerous others.
Yeah, don't rely on air tests. Really just lets you know your detector is turned on and your speaker or headphones are working. You really have to do an in ground test in the ground you'll hunt in. We had several test spots where erosion had made it possible to drill holes at various levels into the bank so the ground was minimaly disturbed. We'd put nuggets on wood poles and test that way. Any interference will throw things. If you can fully tune it out then ok but if it's still there then that's not an ideal place to test in. I dont know the size of that coin but just be aware that gold and other metals detect very different. Iv dug coins and relics feet deep with SDs, GPs abd GPXs. We only ever tested on gold.
Iv never dug gold as deep for its size as junk or relics. Our ground though is severe mineral wise.
By the sounds of it your test area is not ideal and not one id bother gauging anything from.
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #3
Thanks so much for your input, Chilli! Yeah, it's not ideal where I'm at, but even though I'm pretty rural, the dang power lines are EVERYWHERE around here. Just a couple miles north are huge mega-watt lines. I've been trying to come up with a spot I can easily get to to test the machine, but haven't come up with one yet.

I can't remember where I read it, years ago, but Jefferson nickels are apparently good test bits for a larger facsimile of a nugget. They weigh five grams, and are 75% copper and 25% nickel.

Similarly, I'm with you on air tests, but I thought that depth actually improves a bit with a buried target...unless you're over highly mineralized soil? Anyway, I know nothing's ideal what I'm trying to do. I also have sub-gram targets of lead pieces wrapped in red duct tape for testing, as well as a couple of different-sized bits of aluminum can. I thought the 18" coil would be a little better on sub-gram pieces than it is, but perhaps the electrical interference is messing with the sensitivity a bit? I just don't know enough about how severe the impact is from the power lines...beyond the audio wonkiness.

Like I mentioned, I wasn't able to test the machine out stock, and I don't really know what to expect, or if I'm tuning things optimally. All the possible variables are a lot to wrap my head around, and, at this point, I'm still having difficulty getting consistent results from different settings from day to day. I'd hate to wait to learn how to set up the machine until I'm actually out in the field depending on it.

Thanks again for weighing in!
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Thanks so much for your input, Chilli! Yeah, it's not ideal where I'm at, but even though I'm pretty rural, the dang power lines are EVERYWHERE around here. Just a couple miles north are huge mega-watt lines. I've been trying to come up with a spot I can easily get to to test the machine, but haven't come up with one yet.

I can't remember where I read it, years ago, but Jefferson nickels are apparently good test bits for a larger facsimile of a nugget. They weigh five grams, and are 75% copper and 25% nickel.

Similarly, I'm with you on air tests, but I thought that depth actually improves a bit with a buried target...unless you're over highly mineralized soil? Anyway, I know nothing's ideal what I'm trying to do. I also have sub-gram targets of lead pieces wrapped in red duct tape for testing, as well as a couple of different-sized bits of aluminum can. I thought the 18" coil would be a little better on sub-gram pieces than it is, but perhaps the electrical interference is messing with the sensitivity a bit? I just don't know enough about how severe the impact is from the power lines...beyond the audio wonkiness.

Like I mentioned, I wasn't able to test the machine out stock, and I don't really know what to expect, or if I'm tuning things optimally. All the possible variables are a lot to wrap my head around, and, at this point, I'm still having difficulty getting consistent results from different settings from day to day. I'd hate to wait to learn how to set up the machine until I'm actually out in the field depending on it.

Thanks again for weighing in!
Hi again. Yeah the jury, between actual users here on them going deeper in ground is still out. Im on the side saying no. Not that I have ever seen. Id say iv seen the opposite, but where I am its massively mineralised.
Is your coil a newer flat wind? I was fortunate enough to be included amongst the testers of them by Nugget Finder here. The 12" is exceptional well capable of .1 grams a few inches deep in sever ground. I often found tiny bits around 1/20th using it. It punches deep on good size stuff too, multi grammers to ounces. The coiktek flatwinds use the same winding and have similar results. The 15" is brilliant, my pick any day.
My reason in particular for aversion to air tests really grew when I saw the development here by a shop who had 2 technicians build a unit which was put onto Minelab PIs called the SuperFix. It filtered the audio, supposedly picking up minute audio changes by targets and amplifying them. Not a booster, it was beyond that. It also would filter out interference so you could turn your machine on inside your house and get zero interference.
Basically you would run your machine anywhere, get zero interference and hear targets that previously the human ear was not aware of. Great in theory. In the shop they had a Minelab set up there with the Superfix rigged up to it. They would turn the detector on, non Superfix, and it would go nuts. They'd then turn Superfix on. It was as smooth as silk, wave targets over the coil at really impressive distances from it. People were spell bound.
Then some so called testers, I say so called because they were not experienced, were given a couple. They did videos posted on the net showing it get buried gold targets inches deeper than with Superfix turned off. I saw them as was sceptical. I finally was given one to try. Out in the goldfields it was useless. It could filter electrical noise in the shop but other sources it was incapable off. In fact other sources it amplified like it was supposed to targets. He didn't believe me or two others that complained of the same findings. Needless to say numerous got sold, it was a failure and he went broke.
To be honest I don't believe everything Minelab says either. They make great gear but lack competent testers here in Oz. There may be a couple ok but they have many yes men frightened to give honest negative feedback. I knew two that did and they got dumped. I will never forget the GP Xtreme debacle. It was released with great fanfare! Goes deeper than anything, detects to Xtreme Depths. Well in Victoria it did the opposite. An SD2200 could kick its butt on anything over a gram. They refused to believe it. They eventually sent a technician to Victoria, now remember, if it had been tested by honest testers here they'd have known it had problems. There were 20 or so people at the test site on various days over I think a 2 week period. He was forced to concede it went shallower on the nuggets over a gram. It went 3 inches shallower on a 2 ounce nugget than the 2200.
They had sold who knows how many dud Xtremes by the time they rectified it!
The GPX4000 comes out. I knew a tester well, I was with him a few times out in the field. It wouldn't hold a ground balance in fixed. So, it kept getting noisy. You could stop and ground balance then walk around a bit, go back to the exact spot you balanced and put it in fixed and it was now drifted out by a mile. He told them it had issues and the next day he was told to send it back and got dumped. Months later it was released with guess what, the exact issue we saw and he told them about. Like the Xtreme they fixed it, but only after customers complained, not by the testers feedback.
Take the 7000, there are many places a 5000 will leave it for dead with a new Evolution coil on it. So like the bit they say about the minerals make it detect deeper, to them in theory I guess it does, but like many of their other claims in the yrs gone by we saw different.
Hopefully that explains why I think the way I do.
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #5
Wow, thanks so much for taking the time to share all that, Chilli! Very, very interesting!

My Coiltek is a brand-new Elite...I'm assuming it's the flat-wound type you mention? It has the molded, attached skid pad and camo coloration. Although, I can only get a consistent signal on a 0.9g piece of lead. If I fiddle with the frequency and raise it to 250-255, I lose depth, but can sometimes pick up a 0.50g piece. That's why I was wondering about the electrical interference...like it might be messing with the actual performance of the electronics.

I have the 8" Commander mono, but I don't like it. It just doesn't seem very sensitive. If, at some point, I find a shallow location I'm fairly certain has a number of small bits to make it worthwhile, I'll look at a Sadie or something.

There are some new comparison videos on YouTube, can't remember the channel, but the guy has done some really interesting comparisons between the SDC, GPX5000, 6000, and 7000. It is SHOCKING, to say the least! True, the machines have different coils, but the 5000 is the hands-down winner, both on shallow small pieces and deep, large ones. A number of the comments below are from folks thanking him from saving them thousands of dollars on Minelab machines that don't deliver what they promise.
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Wow, thanks so much for taking the time to share all that, Chilli! Very, very interesting!

My Coiltek is a brand-new Elite...I'm assuming it's the flat-wound type you mention? It has the molded, attached skid pad and camo coloration. Although, I can only get a consistent signal on a 0.9g piece of lead. If I fiddle with the frequency and raise it to 250-255, I lose depth, but can sometimes pick up a 0.50g piece. That's why I was wondering about the electrical interference...like it might be messing with the actual performance of the electronics.

I have the 8" Commander mono, but I don't like it. It just doesn't seem very sensitive. If, at some point, I find a shallow location I'm fairly certain has a number of small bits to make it worthwhile, I'll look at a Sadie or something.

There are some new comparison videos on YouTube, can't remember the channel, but the guy has done some really interesting comparisons between the SDC, GPX5000, 6000, and 7000. It is SHOCKING, to say the least! True, the machines have different coils, but the 5000 is the hands-down winner, both on shallow small pieces and deep, large ones. A number of the comments below are from folks thanking him from saving them thousands of dollars on Minelab machines that don't deliver what they promise.
Day near over hear. Im cook tonight. Ill share some more tomorrow. Keep in mind its from here in Aus. But what I can say, is all is not what anyone hears. I'll too show some pictures to at least show im not a BS artist.
Cheers mate 👍
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #7
I really appreciate you weighing in, and taking the time to help me out! Thank you!

I have also been having a conversation with Woody about all this, but he is so busy, he can't take a lot of time with me and answer in detail. However, he did just confirm with me this morning that the electrical interference will overwhelm the circuitry to a degree...beyond just the audio warbling. What he also suggested, and I didn't even think of, is to swap the DD coil on and run in Cancel. He said that should eliminate much of the interference, and allow me to work with the machine in my backyard for the time being.

When I get a better understanding of the machine, I'm going to try to condense all the various guides I have into a cheat sheet that I can glance at quickly and know what I need to do in the field. Difficult to wrap my head around all of it, especially incorporating the special modifications Woody added, too.
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Good luck with it all.
Here's the pictures of the R&D coils I used field testing them. A 12" and 15"
HALF OZ.jpg

a 2 oz..jpg

a 15.jpg
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #9
Holy cow! Thanks for providing the amazing inspiration!!
 

beekbuster

Hero Member
Jan 17, 2015
743
1,650
Detector(s) used
gpx 4500
gpz (died in a fire. rip)
Primary Interest:
Other
I have a 4500 and a z. Wish I never bought the z. It s a good unit, no doubt. Finds gold smaller than the 45, handles the hot spots much better, but the z has not found anything to call home about in any of my cleaned out patches. I will not sell my 45. I prefer the mono coil over the super D. for nugget hunting nothing beats a mono.
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #11
Hi beekbuster --

Before I bought my 4500, I had a discussion with Woody which machine he would lean towards...the 4500 or the 5000. He said the 5000 might have a slight edge towards crumbs, but the 4500 actually responds better to modification, and is better at depth. I'm absolutely fine walking over crumbs, and if I get a hankering to looking for them, I'll just buy a Sadie coil.

The thing that really shocked me is the new videos comparing depth of the various Minelabs like I mentioned above. I think Minelab is going in the direction of lighter/ease of operation/smaller targets, because it brings in more potential hobbyists that way. But if you're serious about the larger, deeper pieces that add up to much more weight, you're better off with the earlier machines with aftermarket coils.
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Holy cow! Thanks for providing the amazing inspiration!!
More than welcome. Whatever you use I always say, "back yourself 100%" and think positive. Those two things in my mind over my years play a major part in success. 👍🙂
A person can have the best they can get, but without those two factors it can spell failure. Often does.
Think positive and back yourself. You might fail, and fail, but don't give up.
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
Hi beekbuster --

Before I bought my 4500, I had a discussion with Woody which machine he would lean towards...the 4500 or the 5000. He said the 5000 might have a slight edge towards crumbs, but the 4500 actually responds better to modification, and is better at depth. I'm absolutely fine walking over crumbs, and if I get a hankering to looking for them, I'll just buy a Sadie coil.

The thing that really shocked me is the new videos comparing depth of the various Minelabs like I mentioned above. I think Minelab is going in the direction of lighter/ease of operation/smaller targets, because it brings in more potential hobbyists that way. But if you're serious about the larger, deeper pieces that add up to much more weight, you're better off with the earlier machines with aftermarket coils.
Hi, good advice. But, not but you are wrong but my experiences here in OZ.
Many knocked the 5000 saying it was only better than the 4500 in Fine Gold mode on tiny stuff. Big, huge Wrong! Minelab called it Fine gold as a name to give it. I used many, many machines here, 4500s, 5000s, with mods, without. A 5000 in Fine Gold using the Flat winds utterly Kill 4500s with or without mods here. Yes tried and saw side by sides 4500s modded vs a 5000 with flats, and without. If my life depended on which to choose?
It would be a 5000, flat wind coil in Fine gold mode. Damn they go deep. Gotta work em slow. Fine gold my butt. 😆
 

beekbuster

Hero Member
Jan 17, 2015
743
1,650
Detector(s) used
gpx 4500
gpz (died in a fire. rip)
Primary Interest:
Other
I
Hi, good advice. But, not but you are wrong but my experiences here in OZ.
Many knocked the 5000 saying it was only better than the 4500 in Fine Gold mode on tiny stuff. Big, huge Wrong! Minelab called it Fine gold as a name to give it. I used many, many machines here, 4500s, 5000s, with mods, without. A 5000 in Fine Gold using the Flat winds utterly Kill 4500s with or without mods here. Yes tried and saw side by sides 4500s modded vs a 5000 with flats, and without. If my life depended on which to choose?
It would be a 5000, flat wind coil in Fine gold mode. Damn they go deep. Gotta work em slow. Fine gold my butt. 😆
Ive never ran a 5k, but I have found pieces with the 45 that were far deeper than I thought it was capable of for the small size of the target recovered. 14" flat wound coil has recovered gold I know for a fact has been swung over by many hi powered machines.
 

Chilli

Hero Member
Feb 10, 2022
680
2,292
OZ
Detector(s) used
Xterra 705
Garrett 24k
I

Ive never ran a 5k, but I have found pieces with the 45 that were far deeper than I thought it was capable of for the small size of the target recovered. 14" flat wound coil has recovered gold I know for a fact has been swung over by many hi powered machines.
For sure. The flat winds were game changers.
In many areas here in Central Victoria a Flat wind on a 5000 blew 7000s away. Owned a 7, after comparing both on undug targets the 7000 was sold. If my life depended on a 7000 with whatever coil was available, or a 5000 with a flat wind id back my life in on a 5000 with a flat wind any day.
7s are ok, dont get me wrong, and if there were no Flats for a 5, id say 7 rules. But as is the 5 beats it overall. 5 in Fine Gold mode with a flat is absolutely killer. Forget the term Fine Gold. It makes people think tiny fine gold. Minelab gave that mode the wrong name. It punches seriously deep on small and big with the flats. 😉
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #16
Could either of you explain to me exactly what you mean by "flat wound coils?" If I try to search, I can't come up with any satisfactory discussions, and no mention that I can find on manufacturer's websites. Above, I was just assuming you meant a mono coil, but now I'm not so sure.

Thanks!
 

beekbuster

Hero Member
Jan 17, 2015
743
1,650
Detector(s) used
gpx 4500
gpz (died in a fire. rip)
Primary Interest:
Other
Could either of you explain to me exactly what you mean by "flat wound coils?" If I try to search, I can't come up with any satisfactory discussions, and no mention that I can find on manufacturer's websites. Above, I was just assuming you meant a mono coil, but now I'm not so sure.

Thanks!
go look for a coil to buy, youll find the information there
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #18
OK...so, this is the description for the coil I purchased:

Description​

The Coiltek 18″ Mono Elite coil is compatible with the Minelab SD, GP and GPX series of metal detectors and has a new innovative mono configuration using LITZ wire and is super sensitive with excellent stability providing you with more depth!
This coil will give you maximum depth as it’s the largest of Elite Series Searchcoils.
  • New innovative Mono size 18″ round (455mm) in diameter
  • Suits the Minelab SD / GP / GPX detectors.
  • Extremely sensitive and quiet in operation Sharp and bright response to targets
  • Optimizes the SD, GP and GPX Minelab Metal Detector performance
 

beekbuster

Hero Member
Jan 17, 2015
743
1,650
Detector(s) used
gpx 4500
gpz (died in a fire. rip)
Primary Interest:
Other
OK...so, this is the description for the coil I purchased:

Description​

The Coiltek 18″ Mono Elite coil is compatible with the Minelab SD, GP and GPX series of metal detectors and has a new innovative mono configuration using LITZ wire and is super sensitive with excellent stability providing you with more depth!
This coil will give you maximum depth as it’s the largest of Elite Series Searchcoils.
  • New innovative Mono size 18″ round (455mm) in diameter
  • Suits the Minelab SD / GP / GPX detectors.
  • Extremely sensitive and quiet in operation Sharp and bright response to targets
  • Optimizes the SD, GP and GPX Minelab Metal Detector performance
excellent choice. That is a flat wound coil. I swing the 14" with great success.
The advantage monos have over dd or super d coils is they produce a signal on the leading end of the coil. A dd style coil sometimes cannot produce a clear signal unless the coil is able to pass over the target unimpeded. Mono is best coil for brush. When you have clear swinging a dd may be an advantage in high trash or interference situations. The Z rules the open ground
 
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bcfromfl

Full Member
Feb 18, 2016
249
302
Youngstown, FL
Detector(s) used
GPX 4500,
Fisher Gold Bug Pro,
Gold Hog stream sluice
Primary Interest:
All Treasure Hunting
  • Thread Starter
  • Thread starter
  • #20
I knew about the advantages of mono over DD, but you all talking about a flat-wound coil threw me for a loop. Do I just assume that all newer mono coils are flat-wound? Thanks!

Definitely gotta use the bungie for this coil! ;-)
 

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