White's Dfx Versus V3i On Gold

[Steve Herschbach]

10 minutes ago, auminesweeper said:

Does the V3i or the DFX have a Live ground phase window when the GB is locked ?

Basically, no. The DFX has a D.C. Phase function and the V3i the Ground Probe, but neither is as simple as say the Gold Bug Pro in all metal mode, where the big number on screen is a live ground phase number.

[Deft Tones]

Thank you both. I understand now seeing the image on the GB2.

I understood that locking a track or ground grabbing (what I thought to be a manual ground balance) takes a "photograph" or snapshot of the area directly under the coil, and I understand the tracking on is more like a motion picture, a series of continuious snapshots.

So, as Steve also mentioned, the offset settings on the V3i, is that offset the equal to or similar to the GB2's ground reject knob?

I do keep mine on the live control toolbar and it's pretty easy to change on the fly.

Thanks again, gentlemen.

[Steve Herschbach]

The V3i is a bit unique as it basically offers either automatic ground tracking and a "track & lock" or ground grab system. However, since White's removed the DFX manual ground balance (G.E.B.) settings from the V3i, they did see fit to add a "Lock Offset" function.

Some automatic tracking systems (like DFX and V3i) feature a "Track Offset" function that allows you to create a positive or negative bias to be applied to the tracking results. V3i added a "Lock Offset" which is basically a manual ground balance control. The difference is it gets the base setting via the ground grab, and then just adjusts up or down from there.

 

"Offset – Selects a slightly + or – ground balance and tracking setting point to enhance ground rejection
and target responses. Typically a “+” offset is used to reduce ground mineral responses and enhance target signal responses (particularly small size targets) in extreme ground types. More rarely “-“ offset may be used to enhance the response of iron oxides in a low iron ground matrix, for example stony iron meteorites in a ground matrix consisting of ice/snow."

[Steve Herschbach]

I see that White's describes the "ground grab" method in the V3i manual as being "Manual Ground Balance" so you have your proof there! I guess it is a manual method compared to tracking but it is still a ground grab methodology.

The GMT for a long time was my only and best example of a detector that does all three basic methods.

1. Tracking

2. Ground Grab (or Track & Lock)

3. Manual

and for sake of accuracy a fourth method exists....

4. Factory Pre-Set

Click images for larger versions....

 

 

[auminesweeper]

Having the off set on the V3i is more of a hybrid version of manual GB, It will be interesting to know just how much adjustment the off set can offer for those who prefer to manually over ride the GB setting.

Where I posted in an earlier post that you can off set the GB via not lowering the coil completely to the ground I think that has a reverse effect in that it actually sets the GB to a slightly more negative setting because by doing that it sets the GB to a lower GB number, So really there is no way to set a machine with a ground Grab to a more positive setting because once the coil reaches the ground those + numbers will not get any higher, So the level the machine see's is as high as you can go.

Or have I got that wrong ? As in + numbers being higher or more positive and - numbers being lower meaning more negative , because the only manual numbers I can intentionally set my machine to is "83" by locking the Tracking before I turn the machine on or by turning the machine on and setting it to "Lock" before the coil reaches the ground then I get a setting of "50" 

John.

[Steve Herschbach]

On 7/12/2017 at 3:47 PM, auminesweeper said:

Or even make that (V3i) tracking system with a variable speed so it could run slower than the MXT and faster so one could utilize the 22khz mode for prospecting

V3i does have a track speed setting. Owners Manual page 34:

"Speed – Selects the speed or aggression of Auto Tracking. Press ARROW Left & Right to select the speed of Auto Tracking. Excessive ground tracking can be as bad for performance as insufficient ground tracking. A speed that keeps up with progressive ground changes is desired. A setting that adjusts significantly when passing over slight (spotty) ground imperfections can cause instability and errors. Ideally select a speed that keeps up, yet doesn’t overcompensate for every unusual rock."

Part of the problem is this is a multi frequency detector and so ground tracking is probably a much more complicated thing than it is with a single frequency detector. Plus, the GMT and MXT have a specific prospecting intent, whereas with the V3i prospecting was probably last on the engineer "worry list".

Also from Link deleted since Findmall Forum update broke all old links

"Tracking Speed, lower numbers equals slower track speed. The V is always tracking as long as auto track is on. The control adjusts the limit of how much it can track at one time. So, (example - numbers are not correct at all - just to give you an idea what's going on), say you have a ground signal that is off by 10000 from where ground really is. If you have your setting at 10, the detector would track at the most by 20 at one sample. If your ground was off by only 8, then it would adjust by 8 as that's less than the limit. But at 10000, it will be limited to 10 at that one data sample. Whereas, a setting of 20 will track at most by 40 per data sample. There are a lot of factors that come into play on how tracking is adjusted - whether it has seen a target recently, how fast the ground is changing, the user adjustable track speed, how close the ground setting is to the current ground. If the ground setting is close to the current ground, it will track to the current ground faster than if the current reading is far away (might be a target and don't want to track to targets)."

[auminesweeper]

6 minutes ago, Steve Herschbach said:

 

"Tracking Speed, lower numbers equals slower track speed. The V is always tracking as long as auto track is on. The control adjusts the limit of how much it can track at one time. So, (example - numbers are not correct at all - just to give you an idea what's going on), say you have a ground signal that is off by 10000 from where ground really is. If you have your setting at 10, the detector would track at the most by 20 at one sample. If your ground was off by only 8, then it would adjust by 8 as that's less than the limit. But at 10000, it will be limited to 10 at that one data sample. Whereas, a setting of 20 will track at most by 40 per data sample. There are a lot of factors that come into play on how tracking is adjusted - whether it has seen a target recently, how fast the ground is changing, the user adjustable track speed, how close the ground setting is to the current ground. If the ground setting is close to the current ground, it will track to the current ground faster than if the current reading is far away (might be a target and don't want to track to targets)."

So would the SAT on the V3i fill in the gaps in the tracking speed like it does on other Whites models ?

I prefer to use the Default relic mode but if the ground phase numbers are above the mid 70's I hit the push pad once or on earlier models push the trigger forward because they have a faster SAT speed which does help with ground noise.

John

[Steve Herschbach]

The last few posts I made give some examples of why a manual offset either positive or negative is sometimes desirable as opposed to a "perfect" ground balance. Tracking or even ground grab gives you what the engineers think is the best ground balance. However, when prospecting I usually run slightly positive. If I ground grab a Gold Bug Pro, I get a neutral ground balance. But the first thing I do is hit the manual + button twice, which makes the detector give a slight response as the coil approaches the ground, my desired setting. It may be the V3i in Locktrac but punched up 1 or 2 points via the offset will produce better results on the tiniest gold targets.

[Steve Herschbach]

1 minute ago, auminesweeper said:

o would the SAT on the V3i fill in the gaps in the tracking speed like it does on other Whites models ?

I prefer to use the Default relic mode but if the ground phase numbers are above the mid 70's I hit the push pad once or on earlier models push the trigger forward because they have a faster SAT speed which does help with ground noise.

John

Welcome to the V3i rabbit hole! Yeah, track speed, SAT, recovery speed, filters - all matter and interact.

[Deft Tones]

Quote

 V3i added a "Lock Offset" which is basically a manual ground balance control. The difference is it gets the base setting via the ground grab, and then just adjusts up or down from there.

That's how I understood it too. You have a great way of explaining things, Steve. Outstanding!

One more question please, so where does a GB2 get it's ground balance base setting from? A preset?

I realize we're splitting hairs for an average detectorist, but the V3i has a reputation of being difficult to ground balance, and as you said, performance is hinged on a good ground balance, so it's something I regularly do and keep on top of by habit. I thought I taught myself wrong for a bit, so I'm willing to be corrected. Thank you.