Minelab GPZ 7000 19" Coil

[Gold Hound]

3 hours ago, goldenoldie said:

I understand how it is designed however i should have been more specific in my previous reply in that as I see it, it is usually the size of the "transmit winding coil or loop" that is the determining factor that governs the depth potential of a coil.

Therefore in this coil it's transmit coil or loop is only 19" x 9" although the way that transmit winding is wound and how it differs compared to the way a normal mono coil winding is wound then at a guess that might produce some extra depth potential.

A case in hand is the way the new Evo and Elite mono coils are wound that has produced extra sensitivity and depth over a normal wound mono coil of similar size.

The question as far as I can see is what size normal wound MONO coil is the equivalent to this DOD or so named Super D type since by way of its design it uses a transmit coil much smaller then its overall diameter compared to the normal wound MONO coil whose overall diameter dimension is the size of its transmit loop.

This is the question that I ask myself.   .  

It is actually the RX area that is most important in determining the depth potential of a coil.

The beauty of the DOD configuration is that it basically has 2 small coils that can detect small fast timeconstance but they also act as one rx winding that has the area of a mono plus the new zvt tech. Oh yeah!

Cant wait for the new coil!

[PhaseTech]

What I'm liking about the design of the 19 coil is that there appears to be more room for sweeping a scoop across, and may even be easier at the back of the coil. This should get rid of the whole issue of getting too close and desensitizing the coil. 

[Reno Chris]

Quote

The question as far as I can see is what size normal wound MONO coil is the equivalent to this DOD or so named Super D type since by way of its design it uses a transmit coil much smaller then its overall diameter compared to the normal wound MONO coil whose overall diameter dimension is the size of its transmit loop.

My opinion, having used the standard coil on the GPZ for a considerable time, is that on big deep gold the 14 inch is roughly equivalent to a GPX running a 20 inch mono and maximum gain, while on small, sub gram gold the GPZ will do better than a GPX running something like an 8 x6 mono. The GPZ sees AT THE SAME TIME the bigger deeper pieces and the smaller tiny bits - and that's the standard coil.

On wiry, specimen or porous gold the difference can be extreme. I can see wiry pieces of 3 to 5 grams at a reasonable depth on the GPZ that the GPX cant see if it is rubbed right on the coil.

My expectation on the larger coil is that it will likely outdo a GPX with a 36 inch coil on bigger, deeper stuff. However that is only speculation as I've not tested the GPZ 19 yet.

[goldenoldie]

1 hour ago, Reno Chris said:

My opinion, having used the standard coil on the GPZ for a considerable time, is that on big deep gold the 14 inch is roughly equivalent to a GPX running a 20 inch mono and maximum gain, while on small, sub gram gold the GPZ will do better than a GPX running something like an 8 x6 mono. The GPZ sees AT THE SAME TIME the bigger deeper pieces and the smaller tiny bits - and that's the standard coil.

My expectation on the larger coil is that it will likely outdo a GPX with a 36 inch coil on bigger, deeper stuff. However that is only speculation as I've not tested the GPZ 19 yet.

I would agree on small sub gram gold the GPZ will do better than the GPX although a small flat wound type mono on a GPX would get closer than a standard wound 8 x 6 mono.

Now when you say on big deep gold I am most interested on what size big gold do you speak of..?.

Also in regards to the 19” DOD to likely outdo a GPX with a 36” mono then from in-ground results that I have been privy too comparing the 14”DOD on larger gold to a normal wound mono of similar diameter then I will say your 36” size coil on a GPX is most definitely speculation.

[Reno Chris]

As far as larger gold, I would be thinking something like 1/2 ounce or larger.

Part of the issue of larger coils on the GPX is that at some point they become impractical. I would say swinging a 36 inch coil is impractical in my opinion. There is also an effect of diminishing returns as beyond 18 or 20 inches, the increase in depth is not as great as the increase from smaller coils (like 11 or 14) to 20.

In my use of the GPZ, I have been continually surprised by the depth of targets it finds on both larger and smaller targets. If you have a different opinion, that's fine. I will say that my opinions are formed of many hundreds hours of use.

[Steve Herschbach]

I think trying to equate GPX coils to GPZ coils is a bit like trying to decide what kind of cat is most like one of my miniature wiener dogs.

[Reno Chris]

Its a crude comparison, but.....

 

The correct answer is an abyssinian cat.

   

All in good fun.

[Norvic]

Ah, when whatever restraints ML have in place that is stopping the aftermarket coil makers are relaxed or removed, suspect we will see the advances made in coil manufacture that we are currently seeing in the X coils. Imagine if it is possible a mono type coil on the Z and before that idea gets howled down, the impossible today is tomorrows possible.

 Crikey the backhoe will no longer be an optional accessory

[AussieMatt]

If they can get a mono type coil to run stable it could be mind boggling but then going to a mono type configuration on the ZVT tech might be regressive rather than progressive?

I'm sure in time further coil innovation & improvement will occur. Hopefully lighter & equally responsive or even more so windings? Whatever they come up with will no doubt be good given we're only at the start of it now 

[Gold Hound]

17 hours ago, Reno Chris said:

My opinion, having used the standard coil on the GPZ for a considerable time, is that on big deep gold the 14 inch is roughly equivalent to a GPX running a 20 inch mono and maximum gain, while on small, sub gram gold the GPZ will do better than a GPX running something like an 8 x6 mono. The GPZ sees AT THE SAME TIME the bigger deeper pieces and the smaller tiny bits - and that's the standard coil.

On wiry, specimen or porous gold the difference can be extreme. I can see wiry pieces of 3 to 5 grams at a reasonable depth on the GPZ that the GPX cant see if it is rubbed right on the coil.

My expectation on the larger coil is that it will likely outdo a GPX with a 36 inch coil on bigger, deeper stuff. However that is only speculation as I've not tested the GPZ 19 yet.

Hi Chris

My observations of the performance of the Zed with the 14in coil line up with yours! Ive now got 271 days at an average of 7.5hrs swinging a day so thats 2032hrs on the zed so I think I can pass judgement on it now!

I think that when the 19 comes out that it will be my new standard coil and that ill only use the 14 when chasing leaders/reefs as small gold sensitivity is a must when chasing them. I am really hanging for the new coil.......... HTFU minelab I want my new coil!