Another Modded Gpx5000 Comparison Video

[phrunt]

The normal popular sizes like 17" round give little benefit on the 6000 to justify the extra size and weight, you have to go to extremely large sizes to give the GPZ a run for its money even though it's on a DOD coil and not a big round mono.  The 19" GPZ coil even gives the 30x30 GPX 6000 coil a run for its money.    Then when you factor in the ground the 6000 is going to struggle with those very large coils.

The 6000 coils do not work well on the 5000.

You've been very busy Chet, I do like the idea of your 6" round GPX 6000 coil.

I guess your focus is now on making yourself a big GPZ coil for your big deep gold hunting goals.

Thanks for your results.

[Drellim]

Chet that is some good work  looking for gold test with gold  you have the know how   For sure  interesting info   Thanks for sharing 

[Aureous]

On 1/10/2024 at 5:37 PM, Chet said:

In pursuit of large gold I have experimented with winding some test coils

Just wondering Chet, how far off are the specs on the various coils you are winding, versus the legacy GPX coils? The X coils guys were suggesting that the 6000 and 5000 coil specs are near identical..... say in the 290-350uH inductance and <1ohm resistance ranges. You say that the older coils don't work as well on the 6000 using your adapter set-up???

[Chet]

1 hour ago, Aureous said:

Just wondering Chet, how far off are the specs on the various coils you are winding, versus the legacy GPX coils? The X coils guys were suggesting that the 6000 and 5000 coil specs are near identical..... say in the 290-350uH inductance and <1ohm resistance ranges. You say that the older coils don't work as well on the 6000 using your adapter set-up???

Coil inductance and resistance is in line with Minelab Detector coil specifications.  I try to wind them for an inductance of 300uH and a DC resistance of 0.33 ohms. Depending on the wire gauge and rounding off on complete turns they have all been between 290uH to 315uH and 0.25 to 0.5 ohms. It would be beneficial to know more about the limitations on these specifications. When I first started winding coils I ran into some coil overload and coil fault alerts and detector shutdowns. Since then I haven’t strayed far outside the normal specifications.
GPX detectors prior to the GPX 6000 had the internal graphite EMI coil shield connected to the coaxial cable shield. The GPX 6000 has separated the EMI shield from the coaxial cable shield and run a separate ground wire. This keeps some of the EMI cross current signals out of the receiver. It has also eliminated some standing waves and cable movement sensitivity experienced with some of the older coils and detectors.
 

[Drellim]

Has anyone ever used silver wire in a coil  being the most conductive  metal  it would be expensive  could it be beneficial  to even use it 

[geof_junk]

1 hour ago, Drellim said:

Has anyone ever used silver wire in a coil  being the most conductive  metal  it would be expensive  could it be beneficial  to even use it 

Yes. Made a PI detector in the mid 1980's and made the coil out some left over Main Frame Computer Teflon coated silver connection wire. The whole unit worked very well on test (Known targets) nuggets getting great depth, but was hopeless when searching for targets due to its clicking audio being its down fall.   

[Aureous]

On 1/13/2024 at 9:56 AM, Chet said:

The GPX 6000 has separated the EMI shield from the coaxial cable shield and run a separate ground wire.

Looks like I'll have to tear-down a 6000 coil just to take a look at that. Very curious..... With your whole-coax-and-chip idea, do you find any bump sensitivity from the external connectors outside the coil?

[Aureous]

1 hour ago, Drellim said:

Has anyone ever used silver wire in a coil  being the most conductive  metal  it would be expensive  could it be beneficial  to even use it 

Yeah I trialed both silver multi-strand and silver coated copper which seemed to have the correct specs per foot but like Geof said, they had a frustrating noise issue. Tried Aluminium wire as well (from Microwave ovens) and same issue. So far, Ive found only 4 types of litz and Teflon/nylon coated multi-strand wire that work perfectly every time.

[Chet]

4 hours ago, Aureous said:

Looks like I'll have to tear-down a 6000 coil just to take a look at that. Very curious..... With your whole-coax-and-chip idea, do you find any bump sensitivity from the external connectors outside the coil?

Any movement of metal near the coil will sound off. It requires some Velcro to secure it to the shaft. I installed a male and female connector in the GPZ 7000 coil cable approximately 24" above the coil to use X-Coils. It was padded inside the shaft to prevent the coil from reacting to bumps. To demonstrate to the nonbelievers I duct taped a Cola can to the shaft at 24" above the coil; ground balanced and swung the coil over a 0.08g test nugget with no detection loss. The can did not create any bump signals. It did sound off as the position was altered when the detector was set down or raised off the ground.

Many types of wire have been used in coils. One company even used aluminum foil ribbon. Signal returns vary in strength and time duration. Most any good quality wire will work with larger targets. 

The signal returns from small gold nuggets is weak and extremely short in time duration. Gold detector coils require small insulated low capacitance strands of wire to be efficient in retaining the short duration higher frequency signals received from small gold nuggets.  Litz wire is being used by most companies for gold detectors. 

 

[Guys gold]

There are two ways to go after depths vs gold size .Though the frequency switch or coil size,then you throw in front end gain.Use coil size for for size and depth,Or crank the front end with a smaller coil and deal with more noise.