GPX 5000 Mods Video

[geof_junk]

5 hours ago, Aureous said:

Only one I didn't try was Mick Quinns from QLD coz he decided to stop doing it as he reckoned his deep mods were finding him too much gold

Aureous the last time I saw Mick Quinn was years ago and he was telling me his was very happy with he latest mod and was heading out to do some more detecting when he met up with me in W.A. 

[PhaseTech]

7 hours ago, phrunt said:

I can't help but think where the mods are said to handle EMI better is because Mick said he's scraping the paint off the housing on many of the detectors that come in for mods to fix the front/rear plate shielding issues.  If as many as he describes come in needing that done then those particular ones are going to be worse for EMI than a detector properly done by the factory until fixed.  I know Woody has also brought this up and done a video on the paint problem with many GPX's so he will also be fixing that on all of his mods.

So, if yours already had the proper shield connection then there would be no difference, to those he scrapes the paint off they'd get a noticeable difference, I say this from firsthand experience with a noisy 4500 I fixed with this simple correction.

 

Even if there's paint on the end of the housing preventing proper contact with the foil, the screw that goes through makes contact with the foil and then the thread completes the circuit. I'd say the difference is extremely marginal. Still, it's the first thing I did with any new GPX box I got in the past - OCD or whatever 😉 but if it can't hurt, then I do it. 

[phrunt]

51 minutes ago, PhaseTech said:

Even if there's paint on the end of the housing preventing proper contact with the foil, the screw that goes through makes contact with the foil and then the thread completes the circuit. I'd say the difference is extremely marginal. Still, it's the first thing I did with any new GPX box I got in the past - OCD or whatever 😉 but if it can't hurt, then I do it. 

That's if the screw is making contact with the shield and even then, it's a pretty minor connection with it only being the thread of the screw and as the foil has holes in it for the screws to pass through they may not even touch, the screws are black painted too, but that wears off with some use on the thread.  It's certainly worth making sure there is a good connection but it seems it's only on older detectors, my 5000 was fine, my Aussie made 4500 had the problem.  

[Tony]

2 minutes ago, phrunt said:

That's if the screw is making contact with the shield and even then, it's a pretty minor connection with it only being the thread of the screw and as the foil has holes in it for the screws to pass through they may not even touch, the screws are black painted too, but that wears off with some use on the thread.  It's certainly worth making sure there is a good connection but it seems it's only on older detectors, my 5000 was fine, my 4500 had the problem.  

Is there just one faceplate screw that actually grounds to the case/board or do all faceplate screws need the clean contact with the case?

[phrunt]

10 hours ago, Tony said:

Is there just one faceplate screw that actually grounds to the case/board or do all faceplate screws need the clean contact with the case?

The alloy housing is has a floating ground, so all it requires if a good contact between the faceplate shield and the housing, they paint the housing though and painted the ends of it so the faceplace sheild just touches the paint, and relies on a contact between a screw and the faceplate sheild but with the precut screw holes that's not all that likely to get a good contact.  All you need to do is scrape some paint off the housing edges so the faceplate sheilds touch metal and not paint.

So, the black coated screws go through the plastic end cover, then the rubber gasket then the precut-out holes in the shielding and then onto the painted housing.  By scraping the paint off the end of the painted housing the shielding touches directly to the housing creating good contact, otherwise you're just relying of any of the threads of any screw to be making good contact to the alloy shielding on its way past which I put the picture of in the post above, would be better if they didn't cut out the screw holes or if the person at the factory puts it in a bit wonky so it touches a screw better 🙂

Minelab realized their mistake as newer ones all have good contact.

[RONS DETECTORS MINELAB]

On 3/7/2025 at 8:33 PM, Northeast said:

1)  What are your general feelings about the mods being done?  Do you think it is legitimate that the stock models can be improved upon by 'back yarders'?  

2)  Have you used a modded detector?  Which ones?  A positive experience?  

3)  Do you think/know if some of the aftermarket mods have actually ended up being used by the original manufacturer in the future models of that detector or other detectors?  

Hi Northeast,

Question 1

I feel there are some concerns in regard to the taxing of the boards, so please avoid the risk of buying older mods or ones not done by someone with a huge creditability and also please insure they come under the typical 5 year warranty or you might end up like the person who bought a second GPX-4500 from JP. Risk Vs. Cost thing should be considered. Hopefully you're getting good returns on your patches to justify this option.

The backyarders do have a strong electronics background and have been able to produce improved results over the stock versions.

Question 2

Yes, I have used 5000 modded models and have many friends that have also owned numerous versions and models all the way back to the F1A4. Only 2 modders left I believe now.

Not the best turn on and go experience for me and many others as there is a huge learning curve and one needs to have lots of time to learn all the many adjustment options available. Basically, the stock and mods both need to be able to hold a proper ground balance with the correct timings in the first place while also using your typical standard adjustments (Gain/Stabilizer) and taking in account any EMI mitigation needed, so not much new going on there. The nuance is the adjustment of the pulse widths being adjusted to match the coil size and gold size you're wanting to go after and the ability to increase the RX boost by having to lower the gain/stabilizer to prevent getting ground saturation noises beyond your hearing separation capabilities.

So basically it’s more for someone that uses it frequently enough to remember the many sequences of settings who will benefit from it the most. The 6000 and 7000 do a better job of hearing a variety of gold sizes in one pass versus having to change so many settings to achieve the same desired result.

Question 3

I would say the GPX-6000 followed the smaller gold capabilities of the modded detectors in its ability to crank it up to the maximum point of hearing the ground saturation in the more mineralized areas while also having the ability to hear the signals amongst all the noise generated. I'm not a big fan of noise so usually run Manual 3 or 4, if no noticeable noise, then I go higher. But, like the mods there is a crossover where you do lose the deeper faint signals running it more quietly.

I am hoping the 8000 and their next low-end model will capture the larger gold timings and also push the gain to the point we will not need the mods anymore though.

 

Ron

[PeterInSa]

 

Ron, Thanks for your comments

Re (With the one I used mostly I could manage to achieve a marginal improved target signal response on a variety of target sizes. I can usually only achieve a depth increase of 1 to 2 inches with the smaller multi-grammar sizes though.)

In The Vic GT the 1 or 2 inches could be the difference between Gold and No Gold.

[Gold Ryder]

Hunted most of the day with the six and got 1 tiny crumb. Picked up the Modded 5000 at the end for about 20 minutes to see how it would do in the hardest pounded flat on the claim.  Banged two 1/2 grammers right out in the open both 8-10" deep.  There has been every gold detector ever made on that flat including mine.  Noboby heard these ever.  Along with about another 8 targets at 10" or so that should of been picked.  I finally got the settings figured out I think. Im pretty stoked. I know several more patches there that are gonna produce well maybe even some big gold like used to get be got there.  But Ill take two halfs every twenty minutes all day🤣🤣 When I was in Arizona I ran the 15" evo up towards standard and -1 on Micks frequency.  After some discussion on what Mick thinks is big gold I decided to run back down towards +3,  I worked on this pounded ground.  RX 6 Stabilizer 4, TX around 4 oclock. Targets at the surface sounded like nails. 8-10" later they turned into gold.   Impressive to say the least. Might be something to this afterall. Ill keep updating. Got better less pounded patches to rework now. 

[PeterInSa]

Hi GR, Like my mate in South Oz, he's going great with his Modded 5000, now his 6 with an extra coil is for Sale.

Are you doing Likewise.

I think mate should keep the 6 as a backup detector, and as a detector to use when he gets a pain in the back from using the 5k.