Bruce Candy Technical Paper - GPZ 7000 Zero Voltage Transmission (ZVT) Explained

[Trent King]

Very informative, thanks for posting Steve.

[DDancer]

Read it last night and again this morning.  Very informative and it falls in line with what JP has been explaining.  The way its operating clears up a lot of my thoughts and confirms others.  The processing involved is pretty steep as well as how the system is utilizing the new transmitting/receiving technique.  Very cool.

One thing I do wonder about is that the article focus's on large targets but does not mention the small stuff.  I wonder if the increased sensitivity to small stuff and specimens are just an off shoot to what the article pretty clearly explains that the detector was pushing for large targets at depth.  It makes sense that that kind of focus would create the offshoot however I have to wonder at the surprise people had when the itty bitties and species started singing.

As Qld Sandy mentioned I have to wonder at the validity of the testing as well, and I did note the old mindset for GB being used on the GPZ pretty much always applied.  I don't think it will make much difference but the testers might want to give it a go for accuracies sake.

Addendum: Just read JP's comments on how the data is handled for the tracking and GB.  Leaves something else to be said about independent testing~ and that's not a bust on those who have.  I think its outstanding that those people are sharing.  But being so new hic ups in testing are to be expected.

My experience with the GB has already lead me to do what the manual says.  I found that pumping the coil did not quite the machine down at all.  Only sweeping for a minute or so did and pumping after hitting a test piece lead to a noisy machine that made picking up the test piece difficult. 

My thoughts on timing and a logic tree for decisions on settings were both confirmed and thrown out the window   I'll just keep a quick reference with me on the modes and settings as relates to where I'm hunting.

Great post Steve and thanks to Mr. Candy for the work and info.

[Sourdough Scott]

Makes me wonder why this didn't comenout with the owners manual. And with this technical paper, there is not much need for the manual. Except for the mapping aspect.

[cobill]

Steve, what a fantastic post...that's why I visit this forum daily. I printed the PDF out, so this old dog can learn some new tricks.  

 

Bill

[Jonathan Porter]

Makes me wonder why this didn't comenout with the owners manual. And with this technical paper, there is not much need for the manual. Except for the mapping aspect.

Believe it or not, the biggest problems I've seen with people with the GPZ 7000 are experienced GPX users, those who follow the manual and don't try to GPX the GPZ are fine. The animation Guide on the detector start screen clearly shows the method required, Bruce's White Paper just explains more succinctly the reasons behind it and some very helpful tips on getting that process down pat.

 

JP

[Sourdough Scott]

JP's tips and advice. This tech paper and some of the manual make the most sense to me. 

I have totally wiped the memory slate clean of the GPX and have started reborn with the GPZ.

With experience comes knowledge. I read,read,read. Try to absorb. Then apply it with hands on.

Thank you Steve, JP and all with the helpful knowledge. 

[Norvic]

Goddess of gold was on my side, just started it up in default followed on screen dirx, 5 minutes later started picking up pieces. Hour later no more signals started buggerising with settings, got GPZ into a unstable position, reset to default and back into it again.

Simple early lesson, reminds me of the days way back with the Deepseeker & A2B, belief was you turn up everything you could, really making machine unstable and unusable. But a lot run around like that regardless of taking notice of the clear Garret instructions to turn sensitivity down to suit ground conditions and have as stable a threshold as possible.

That was a bit difficult with those old machines, but simple with the GPZ.

[beatup]

Thanks for posting the link Steve,can always use a bit more education.

[Goldnomad]

Russ, That's probably a good analogy.

The first of the Holden Commodore engines had a computer with a "Block Learn Memory", which tracked the sensors and actually would substitute a value for one that went missing or out of range. It would also learn and update the fuel curve for engines that were worn or had a lot of milage.

 

I wonder if the GPZ does a similar thing?

Now I get it Sandy!!!

I should be putting racing fuel in my 7000 not 91 octane

 

Robert

[jasong]

Something relevant in this paper is being discussed in another thread: 

 

The best way to ground balance initially after switch on with the Quick‑Trak trigger depressed, is to sweep the coil in a typical side‑to‑side search mode at the expected operating height above the soil surface

 

IMPORTANT! DO NOT ground balance using a coil up and down motion (like one would do using a PI detector) initially after turn on with the Quick‑Trak trigger depressed. This does not give the initial calibration enough different soil information to calibrate optimally. If ground balance is required again sometime later (but without turning the detector off ), ONLY THEN is the usual (PI type of ) ground balancing up‑and‑down coil motion OK.

 

 

It seems like everyone is saying to not do the up and down typical PI balancing motion, even to avoid doing this on targets.

 

But what this paper seems to be saying is that the side to side motion is to be performed at initial startup and then thereafter it is actually OK to move the coil up and down for balancing and I'm assuming also over targets as well...?