Ground balance not optimal

I did some comparison testing today between my Z and 4500.
In an air test on a 5c 10c an 50c coin the Zed had a range increase over 4500 of 19% 22% and 26% respectively.

Seems the larger the target the greater the advantage, but when the coins were buried the advantage passed back to the 4500.

In testing some nuggets I found that the Zed had almost the same in ground range as the air test IF the ground balance was in a certain state.

I am convinced that the Zed ground balance routines are causing a great loss of depth. I don't have a ferrite so don't know if this is related.

There is much room for refinement, the air tests show this, but I am quite disappointed that my 4500 has better performance on inground nuggets over half a gram. The audio response is far better, louder and not easily missed, where as the Z is weak and easily missed.

I should've waited for the 7500 as I did with the 4000 waiting for the 4500. I hope the ferrite will help because the potential is all of 40% on big stuff if the ground balance can be sorted.

Cheers.

alchemist wrote:
I did some comparison testing today between my Z and 4500.
In an air test on a 5c 10c an 50c coin the Zed had a range increase over 4500 of 19% 22% and 26% respectively.

Seems the larger the target the greater the advantage, but when the coins were buried the advantage passed back to the 4500.

In testing some nuggets I found that the Zed had almost the same in ground range as the air test IF the ground balance was in a certain state.

I am convinced that the Zed ground balance routines are causing a great loss of depth. I don't have a ferrite so don't know if this is related.

There is much room for refinement, the air tests show this, but I am quite disappointed that my 4500 has better performance on inground nuggets over half a gram. The audio response is far better, louder and not easily missed, where as the Z is weak and easily missed.

I should've waited for the 7500 as I did with the 4000 waiting for the 4500. I hope the ferrite will help because the potential is all of 40% on big stuff if the ground balance can be sorted.

Cheers.

Alchemist, I am not a former 4500 user, just the SDC so I can't add anything from practical experience, apart from versus the SDC, but something doesn't seem right in your comparisons versus the live field tests reported by others on actual field nugget finds, on this and other forums, that say that the Z is killing the others?

Have you thought about the other possible reasons for your findings.  eg. settings used, GB, difference between the detectors responses to halo effect, faulty detector, etc?  Remember others have had issues with their Zeds.

G'day Rob,
                     Yes I've considered all those things. It was certain behaviour out in the field that raised my suspicions. The air test was outstanding 27 inches easy on a 50 cent, and only 21 inches on the 4500.

But what I saw in ground goes to show that air tests are indicative of very little. I would've hoped that on general gold types i.e. soild, non-pourous, that the Zed would have equivalent ranges. It seems the Zed could be a niche detector, like the 2300. The Gpx is a full spectrum machine depending upon settings and coil used.

I think besides something amiss with the ground balance, a lot of the problem lies in the Zeds weak audio. The Gpx target signal jumps out and is clearly evident even at the extreme range. The Zed however is acceptable at medium ranges, but at extreme range the signal is muted and basically a perturbation rather than a solid peak in the threshold. Even air testing the signal can be heard way way out but it is so weak.

I found that in some situations a form of "Lunk's settings" can help on the deepest targets.

http://www.detectorprospector.com/forum/topic/830-lunks-zed-settings/

I adjusted them slightly
Volume  6 to 8 (I use phones)
Threshold  30 to 32
Volume Limit  4 to 6
Audio Smoothing  Off
Gain  18 to 20

I think I'm going to need to build an audio expander/limiter to try and lift the peak, otherwise it will become so tiring trying to discern these weak signals from the background. I think the audio routines need to be based on the Gpx. I have my Gpx audio setup to compand, but the Zed doesn't have as much flexibility.

Respecting the ground balance, I've found that I need to cover my old patches 2 or 3 times. Because the first time in some cases gave nothing, but doing it again or a third time revealed a number of very deep nuggets of different weights and forms. I keep my settings fairly consistent, this only leaves the state of the ground balance.

This is not an unhappy whinge session. Minelab are requesting feedback so that they can improve upon this amazing detector, so here's mine. The future looks golden. I am certain even with its present failings, very little will escape my GPZ/GPX net.
Cheers

G'day alchemist

You say the " Ground balance not optimal" I thought the same thing, for quite awhile, that was before I got to use the "Ferrite" it made quite a difference.

I don't know what your ground is like, but I thought mine wasn't that bad the 4500 never seemed to have much of a problem, but the 7000 didn't go well on the same ground.

I think if you get the ferrite and repeat the same tests you have described you will most likely be surprised and notice a difference.

Also I think your running  your threshold way to high at 30 to 32, the FP is 27 which is ok but with the B&Z booster and dual speakers I run I find that 25 is much better, and gain now sensitivity at between 9 to 12 volume limit 10 and volume at 10 or 12 with the B&Z booster I can control the volume much better with the booster.

Just in my opinion you would be better running your volume a bit higher and your threshold a bit lower, you will get a better variation in target response this way.

On the ground I am detecting "Bad Alkaline Type" after using the ferrite to get the Ground balance right I then go to Manual GB instead of Auto GB.

Hope some of these tips are of some use to you and where your detecting.

cheers dave

As Lunk says his settings are counter intuitive and it seems to me that all it is doing is making the big targets stand out more but perhaps at the expense of losing the smaller targets.

I am quite surprised regarding the audio comments as I am quite deaf in the right ear and way down the gurgler in the left ear high freq response, so I just clip the WM12 on the harness beside my left ear and that just booms in on small & large signals using the default audio settings. Too bad most of them are junk, as digging junk from depth can become a bit boring, but it is good exercise.

I prefer the WM12 as when detecting with others I want to be able to hear and respond to them when they call on the UHF.

Thanks Dave & Rob for your comments.

I hope the introduction of the ferrite will improve things.

I adjusted those settings while over a 2 grammer at 14"
The 4500 boomed in, and the Z was very weak until I tried those settings and it improved markedly.

There is far more to the audio processing on this machine than meets the eyes.

More food for thought.
http://www.detectorprospector.com/forum/topic/1065-when-no-one-is-looking-try-this/#entry11452

Yep, all good info. I think that this basically means that while the Z is promoted as a simple to use machine, there are several ways to play with those settings, if you aren't getting the type of responses that you would like. But take care that you aren't dumbing down the machine in the process, unless that is what you want to do.

I must admit that because of my hearing loss, I tend to put up with more "noise" in the audio than others would. This is also likely due to a job I had when I was a pup, of having to try and monitor the quality of 3 audio and video streams at the same time, and my way of doing that was to have them all a bit louder than others preferred. Using the ears and the brain to do what some would like the machine to do for them.

I am a big fan of the 4500, I regretted to trade in mine for a 5000, this is the reason why I bought the Zed, but I never had any problem with ground balancing or the audio with my 7000, have you consider that can be something wrong with your machine? I have a ferrite, provided free from Bendigo Gold World in Bendigo, but I never had to use it.
I don't like air tests and I don't like to compare the Zed with other detectors, I have what I consider the best and I am happy with it, I don't need to know how the 5000 or any other detector would perform because I don't have them any more so I prefer to concentrate with the one I have now.

You're a "glass half full" type of guy goldquest where as I'm a "glass half empty" type of guy.

Now's the time to voice any dislikes, so the next model will be even better.

I have found that as I get used to the Z that I have constantly tweaked the settings as I become more used to the machine and I am constantly improving the performance. I also believe that you have to tune the machine to what suits you best with regards to hearing ect.
I am currently running a high sensitivity and reduced threshold which varies for different ground types.
I haven't got a ferrite as yet but if it helps reduce ground noise will give it a go.