White’s Goldmaster GMT Original 6x10 DD Coil

[Ironhide18B]

Hello,

         Greetings all, and I am stoked to be a part of the forum here as a new member. I have a question that I believe the esteemed quorum here can help me with. I have a White’s Goldmaster GMT with the original 6X10 DD coil that indicates “Overload/ Lift coil…” warning whenever I go past the 7 or 8 position on the Gain irrespective of whether it’s in the air, or on the ground. It just sounds off regardless.

I have had the GMT with that coil since I bought it new back in 2008. The only other issue I have ever had was the built-in speaker had to be replaced.

Any information on why that is occurring would be helpful. I have always taken good care of the detector, careful to not abuse it in any manner, but this issue with the coil vexes me.

 

Thanks again.

 

V/R,

Ironhide

[Steve Herschbach]

3 hours ago, Ironhide18B said:

Hello,

         Greetings all, and I am stoked to be a part of the forum here as a new member. I have a question that I believe the esteemed quorum here can help me with. I have a White’s Goldmaster GMT with the original 6X10 DD coil that indicates “Overload/ Lift coil…” warning whenever I go past the 7 or 8 position on the Gain irrespective of whether it’s in the air, or on the ground. It just sounds off regardless.

I have had the GMT with that coil since I bought it new back in 2008. The only other issue I have ever had was the built-in speaker had to be replaced.

Any information on why that is occurring would be helpful. I have always taken good care of the detector, careful to not abuse it in any manner, but this issue with the coil vexes me.

 

Thanks again.

 

V/R,

Ironhide

Sounds like the coil has gone bad. I sold a huge number of GMTs plus owned a few and I'd see that every once in a while.

[Ironhide18B]

Mr. Hershbach,

                           Sir, thank you for the prompt response. Much appreciated, however, I try to use every experience as a teachable moment going forward. That being said any ideas on causation? Can it be repaired? And is it worth hanging on to it and using it as is?

Nice to know you can still get SME’s to give good gouge on long-in-the-tooth metal detectors that I’m hanging onto for sentimental reasons:)

Thanks again, and I appreciate the venue here.

 

Sincerely,

Ironhide

[Steve Herschbach]

Why? No idea with yours in particular. White’s coils are foam filled and with lots of use/banging around the foam can deteriorate and windings shift. Repairable? Not realistically as labor and shipping to undertake the task would exceed the cost of the coil. The normal fix was toss and replace. Can you use it? Sure, just can’t set sensitivity so high as to cause it’s to overload.

Me, I’d replace it.

[Knomad]

Steve is likely right, the only other things you can check are for bad connections by moving the coil wire around as well as wiggling the potentiometers by moving the control knobs, do this with the coil in the air and away for any metal or electrical noise source, if that triggers it to overload like you mention you have the source.

I keep my GMT and think they have always been Underrated, no they do not have the sensitivity of the newer multi frequency machines, but at times that one frequency bunches deeper in bad ground, AND I love the Constant Magnetic Sand number readout, AND Constant Probability of Iron Readout, Just what you really need in gold country..!  Add to that the Ground Grab and Whites weight Balance, and you have one Sweet Machine made in Sweet Home U.S of A.

[Geotech]

On 3/16/2025 at 9:01 AM, Ironhide18B said:

I have a White’s Goldmaster GMT with the original 6X10 DD coil that indicates “Overload/ Lift coil…” warning whenever I go past the 7 or 8 position on the Gain irrespective of whether it’s in the air, or on the ground. It just sounds off regardless.

First, unplug the coil and see if the detector still overloads at high gain. If not, then the coil null is out. Fortunately, the 6x10 is one of the easier coils to fix. You will need to split it open, re-null it, and then re-seal it. If you decide you want to do this, I can walk you through it.

[Ironhide18B]

Geotech,

                Thank you for the response and information. Yeah, I’m pretty sure its that particular coil because the other 6-inch micro tireur coils does not have that issue.

I’m fascinated though with the renulling procedure. Could you describe it further or do you prefer to go point-to-point?

Thanks again.

Ironhide18B

 

[Ironhide18B]

On 3/16/2025 at 11:02 PM, Steve Herschbach said:

Why? No idea with yours in particular. White’s coils are foam filled and with lots of use/banging around the foam can deteriorate and windings shift. Repairable? Not realistically as labor and shipping to undertake the task would exceed the cost of the coil. The normal fix was toss and replace. Can you use it? Sure, just can’t set sensitivity so high as to cause it’s to overload.

Me, I’d replace it.

Steve,

           Thank you, I’ll probably grab another one from someone. I love my White’s GMT!

Cheers,

Ironhide18B

[Geotech]

The coil consists of an upper & lower plastic shell that are cemented together. First, take a Stanley-style razor knife and cut the seam open. Usually once you get it started it's not too hard to run the knife around the seam, just be really careful. The housing should then split apart. 

Inside there is a foam insert that holds the coil windings, and on the surface of the foam you will see a single strand loop of wire that is seemingly randomly placed and glued down with hot melt. This is the "tweaking" wire for the null. Basically you move it around to deepen the coil null. This is best done with an oscope but can be done without by using a chunk of ferrite and minimizing the distance at which it overloads. To move the tweak loop around you need something that can soften the hot melt; a heat gun or a soldering iron. 

When the null is as good as you can get, close the housing back up. Before you reseal it, double check the null as it can shift a little bit due to the shielding on the bottom shell. To reseal, apply an ABS cement around the seam. Black ABS cement is easy to buy at the local DIY store, if you want white cement you'll have to make it yourself using scrap white ABS plastic shavings and MEK. I mix it to a consistency of thick syrup and apply with a syringe.

This is a forest-level description. If you decide you want to do this, I can give more details on the trees.