Garrett Ace 350 / Euroace manual Ground Balance mod

[craighkzn]

Hi all


New to these forums, but thought I would tell you about a mod that I have done to my Euroace. Would also work on ace 250 / 350.

Warning....will void your warranty etc... But man, what a difference. Like having a PRO for 250 money...

The detector works amazingly on low mineralised ground, but really starts to miss things on highly mineralised ground, like we have here in some parts of SA. I would get to the point where a coin that is readeable in air at 12 inches, would be invisible at 3 inches in an open hole.

I started digging around in my ACE, and found the onboard potentiometer that seems to set the factory GB preset. All I did was carefully remove the SMD 20k pot from the board with a small soldering iron, and ran two wires to a Mini 20k pot which I mounted under the onboard speaker ( Where some guys mount the volume control mod..) this now allows me to press the pinpoint button, and ground balance the euroace just like any other manual GB machine.. I can set it to null, positive or negative with my external control.. This now picks up the same coins up to 8 inches in really heavily mineralised ground, but does not effect the target ID.

I am so chuffed with my euroace now, so thought I would just let you guys know that this is possible (not sure if it has been done elsewhere)

Pics attached...pcb pic from another forum, but points to correct pot..





Cheers

Craig

[gallileo60]

Very cool, thanks for sharing.....

[norfolksquit]

Hi all


New to these forums, but thought I would tell you about a mod that I have done to my Euroace. Would also work on ace 250 / 350.

Warning....will void your warranty etc... But man, what a difference. Like having a PRO for 250 money...

The detector works amazingly on low mineralised ground, but really starts to miss things on highly mineralised ground, like we have here in some parts of SA. I would get to the point where a coin that is readeable in air at 12 inches, would be invisible at 3 inches in an open hole.

I started digging around in my ACE, and found the onboard potentiometer that seems to set the factory GB preset. All I did was carefully remove the SMD 20k pot from the board with a small soldering iron, and ran two wires to a Mini 20k pot which I mounted under the onboard speaker ( Where some guys mount the volume control mod..) this now allows me to press the pinpoint button, and ground balance the euroace just like any other manual GB machine.. I can set it to null, positive or negative with my external control.. This now picks up the same coins up to 8 inches in really heavily mineralised ground, but does not effect the target ID.

I am so chuffed with my euroace now, so thought I would just let you guys know that this is possible (not sure if it has been done elsewhere)

Pics attached...pcb pic from another forum, but points to correct pot..





Cheers

Craig

Hi does it matter if pot is Linear or Logarithmic, cheers?

[craighkzn]

Hi all

Sorry.. I've been away for a while..

Yes, this is the preset GB pot, which, with my mod, you are making external.

By simply pumping the coil off the ground, and adjusting the pot, you are nulling out the ground (ie: ground balancing the machine)

It works really well. I have since purchased a Atpro, and was able to use them together before Selling the 350.. With the GB mod, it was exactly as sensitive as the Pro in all ground situations...

[craighkzn]

The other pot appears to set the VDI calibration by the way..

[craighkzn]

Just to clarify guys..

When using my mod to GB, the following applies.

When pressing the pinpoint button, bring the coil down to the ground ( or pump up & down)

Should the tone get louder near the ground, ground is hot.... Turn dial until the tone remains unchanged as the coil reaches the ground....this is now balanced.

Should the tone disappear as you approach the ground, you have gone too far ( negative GB)

Release & press pinpoint again, and turn the pot until tone remains unchanged ( neither louder or softer near the ground)

Cheers

Craig

[flgliderpilot]

Ok, I tested this on my 350 and it does not adjust GB, it only adjust TID. In other words, it does not work.

At first it seems like GB, because when you press pinpoint and lower the coil, as the tone increases, you can reduce the tone with the knob. BUT: Raise coil, press pinpoint again, and you will need to do it again, and then again, and then again, until you have the knob turned all the way in one direction and it behaves exactly as it did the first time except the target ID is wrong.

I also tested in wet sand, and it made no difference in target depth, only id.

IMO this pot is for only tuning target id, which explains why it's set at the factory.

And now I've voided my warranty :|

[Keppy]

Ok, I tested this on my 350 and it does not adjust GB, it only adjust TID.

At first it seems like GB, because when you press pinpoint and lower the coil, as the tone increases, you can reduce the tone with the knob. BUT: Raise coil, press pinpoint again, and you will need to do it again, and then again, and then again, until you have the knob turned all the way in one direction and it behaves exactly as it did the first time except the target ID is wrong.

I also tested in wet sand, and it made no difference in target depth, only id.

IMO this pot is for only tuning target id, which explains why it's set at the factory.

And now I've voided my warranty :|

That is why i will not mod my detectors...And i would never buy a detector that someone had added any type of mod to..

[flgliderpilot]

Well, I just soldered the original pot back on, no real harm done except for the hole in the case where I had the pot mounted. Fortunately it's hidden inside the battery compartment. Wish I'd found these threads before I started:

I already did a mod where I panel mounted both those trimmers. I mounted two pots under the battery cover up in the top corners. I figured one was GB and the other was threshold. Well all it did was mess up my TID. I called Garrett and they told me that both trimmers were for TID. They said the GB could not be adjusted. So I put it all back. Those trimmers were a pain to desolder and resolder. I will tell you from experience. Don't waste your time.

(Links removed by mod for rule violation)

[flgliderpilot]

... read further down mod does seem to work ... (edited my earlier posts about it not working)

[Treasure_Hunter]

Please note we do not allow posting links to other forums..

[craighkzn]

Hi All

In response to those who say this mod does no work.... You must have something wired wrong, as this absolutely does work, and I tested it successfully with all kinds of VDI... Was able to completely null out a ferrite test rod, as well as ground interference, without any impact on VDI readings.....

I was merely sharing what absolutely works..tested against my AT pro....I suspect you wired the wiper to the wrong contact, thus varying the total through resistance..

[craighkzn]

With the correct pot & wiring, I was able to swing the GB completely from one end to the other, with no impact on VdI....this was the first thing I tested, using foil, copper, ferrous etc....

Once set, the ground would have no impact on my pinpoint tone...I'm sure you have wired your pot wrong....

I would not have posted this had I not been very happy with the results, and would not have expected any different response from the manufacturer...

You need to ensure that the total through resistance of the pot is the same as the small SMD pot that you remove....all 3 contacts must be wired...

I have since sold my 350 to a friend who continues to enjoy it with the GB mod....

Good luck guys....just sharing what worked for me...and I doubt they changed the circuitry for different markets.. (Unless the Euroace is different to the 350) My pot was a 20K linear pot.... Would be interesting to hear if yours was too?

[flgliderpilot]

... removed this post ... read further down

[Dig-SC]

This mod works good, in fact very good. when you are connecting the potentiometer to the board you have to only use two wires. On the board connections #1 and # 2 are on the same trace. You must use only # 2 and # 3 connections points. Likewise you only use #2 and # 3 connections points on the potentiometer that you will be installing. If you don't know the #'s of a potentiometer, which is #'s 1, 2 and 3 you can google potentiometer number layout and see which number is in which position. When wired up correctly the VID, TID will not be effected in anyway.

I have owned and operated a radio and electronics shop for the past 30 years.

I hope this will help someone, but remember you have to be very careful because the traces in that part of the board are very fragile. For safety of the traces, I followed the traces backward and forward until I come the the next component and made my connections there.

Thanks, hope this helps
Dig-SC