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Extension Cable Gpz


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I'm just curious if anyone has created an extension cable for the GPZ 7000 coil. I am working in some narrow spots inside my gold mine and I would love to have the control unit in a backpack on my back and just use the coil without the bulk of the detector. 

Mlgdave

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mlgdave - great question.  I tried to like it but I'm out of likes :ohmy:

Be perfect for when the little coil comes out (:tongue:).

OR, even more exciting, put the unit in the backpack, the WM12 on the shoulder and the small coil on the shaft of your choice - hey presto - super light weight GPZ!!! 

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I have not heard of such a thing and given how finely tunes/balanced the GPZ is I would be concerned about how extending the cable might have some impact on how the machine works.

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You and your logic Mr Hershbach - such a kill joy :laugh:

I understand where you are coming from - changing the length of an exhaust pipe changes the way an engine breathes - maybe it would make a difference to the Z. 

This has been done with many of the GP and GPX series when used on drag coils - unit on the vehicle and long cable to the dragged coil.  Were there any changes/mods required to the unit or the type of cable used to allow for this.  

Reg Wilson might be able to comment on that last bit?  

I also suppose it is not just a matter of getting the right connectors, a cable and giving it a go - it is knowing what the cable consists of.  I am not technically minded - do all/some/most cable innards consist of different materials or are they all essentially the same?  

Probably not high on Minelab's list of things to work on/respond to but would be interesting. 

 

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I can tell you what Minelab would say because here is what they say regarding the GPX at https://www.minelab.com/knowledge-base/frequently-asked-questions

I Would Like To Extend My Coil Cable, Can This Be Done? No, cable characteristics are matched to coil windings at manufacture, so extending the cable will reduce the performance of the coil.

But as you say people have done it.

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On 3/6/2018 at 6:54 AM, Steve Herschbach said:

I can tell you what Minelab would say because here is what they say regarding the GPX at https://www.minelab.com/knowledge-base/frequently-asked-questions

I Would Like To Extend My Coil Cable, Can This Be Done? No, cable characteristics are matched to coil windings at manufacture, so extending the cable will reduce the performance of the coil.

But as you say people have done it.

And if you look at the cable ends it looks like a proprietary connector, 4 fat pins, 3 skinny pins. However I still wanna give it a go, I am in some stopes that are only about 30" wide and to use the GPZ as its designed is pretty tough and all of a sudden taking its toll on my left shoulder (rotator cuff), I am detecting the old mine workings and a lot of its overhead. Its for sure giving us an advantage and we are finding gold that was missed and am willing to do a bench test (well actually its a REAL test) as I have left some gold in place in the mine with a cable extension

mlgdave

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  • 1 year later...

Without seeing a circuit diagram it's hard to say .

Generally we are dealing with a transceiver - the box & 2 antenna systems - 2 coil windings .                                                   I say antenna systems because an antenna is 1 component in a system , the feed-line [ the wires ] are another component , and so the box another device in the circuit .

So this is RF - radio frequency , that means tuned circuits - every component is tuned to every other component in that circuit .

You change something in the circuit , you have to check for the tune of the circuit [ calibrate / measure ] and retune as needed .

Without more info on the hole circuit and the ability to test for tuning , you can't really tell how small a change will affect it .

Some electricians call RF black magic 😉

 

 

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The main requirement for an extension lead is quality enameled  cable. It has to be super flexible with quality enameling. Flexing is something that most PI detectors hate. Keep the solder contacts very short (less flexing again) and stiffen the last 6" of cable going into the plug. Part of what ML stated is correct. If you use the ext cable with a high inductance/high resistance coil, the totals will lose you performance. I cant comment on a GPZ but If you have a GPX coil with inductance below 300uH and resistance below 1 ohm, you can run an ext cable with zero loss of performance. You're gonna have fun with removing the enamel off the wire effectively....use a mixture of heat, acetone and sandpaper. 

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