Help with VDI

[Daugela]

Question -

I sweep my VX3 in factory C & J mode in my test garden over my wife's wedding ring. On the surface. Small thin 14k ring.

VX3 sporadically hits it. When it does it's a blurp at -6 through 5. This is in 3 frequency mode.

MXT hits every time. Registers foil, but consistent hit.

Nickels are the same way.

VX3 in standard C & J mode, 3 frequency. It's inconsistent between +3 and +32, just all over in between.

MXT - consistent hit with +20 everytime,

But in either 22.5 or 7.5, the nickel is dead on consistent +20.

Why does it become less stable in 3 frequency mode?

 

[burlbark]

In 3 frequency you are getting an average vdi over the 3 different frequencies. If you open up the span you should get it to hit more often. I dont know your gain or disc settings

You can run single frequency like you said and get more signal in the ground on more gold friendly frequency 22.5 or 7.5.

I am going to assume that you are not using the same coil on both head units. The d2 is pretty good about subduing mineralization and if the ring is really thin you may be seeing some of this happen but not likely as I found countless rings and pull taps with mine. The 950 coil really likes to punch down the middle and is really sensitive in that cone field, but it gives up the coverage of the d2.

It really is more stable in 3 frequency and you will find more depth running one frequency at the cost of having to double check chirps.

 

[Larry (IL)]

Something does not sound right, the VX3 should do just as well as the MXT on target ID. Have you tried using the MXT coil on the VX3?

 

[jalon]

something seems to be going on with his VX3. He has also posted with pinpointing trouble. I ask again, is the VX3 new? If so, it seems prudent to call Your local dealer, or Whites service dept. They are the best and will solve your problem.
John London

 

[Daugela]

Hey guys. No it's not new. Used but only a few months old. I did call White's and spoke to them about the pinpointing. Seems like it's user error. Marry assured me the two are completely different processing units and would not pinpoint the same. Don't get me wrong, the pinpointed works, just seems SUPER sensitive.

As far as the VDIs. Possibly user error again.

Doing an air test, the VX3 is dead on. Especially waving the target above the coil. But in the garden, it's not good. EMI? I don't know. I'm taking it out today and will see if it reacts the same in a different location.

BTW, I'm using the 950 on the VX3 and a 4X6 on the MXT. I actually switched them. The 4X6 is not V rated, but seemed to work fine with the VX3. No overload or anything. Not sure how to confirm if it's optimized for it.

thanks

 

[Larry (IL)]

If the 4X6 is optimised for the V series, it will have a V at the start of the date code on one of the mounting ears.

 

[Daugela]

If the 4X6 is optimised for the V series, it will have a V at the start of the date code on one of the mounting ears.

Yeah, my 950 is obviously optimized. I was just saying that the "MX" serial number on the 4X6 seems to work fine with the VX3...

 

[Rob (IL)]

I don't understand the difference between your MXT and VX3. I used a MXT 4 or 5 years. If I had your VDI problems I would never have switched to the V3I. I only difference I ever noticed is the the nickles usually were 20 on my MXT and are usually more often 19 on my V3i. The VDI on the V3I are no more erratic as your's are.

It doesn't sound right.

 

[grumpyjohn]

With the V series of detectors a good ground balance is essential. Are you sure this is the case with your detector! If it is balanced properly I would suspect a machine fault.

 

[Rob (IL)]

RX makes signals bigger ot smaller, it is a pre amp. Disc is an adjustment to see smaller signals (more signals) or only larger signals ( bigger or shallower).
[attachment 257344 2013-02-16_182838.jpg]

 

[yukonbuck]

Check your vdi disc settings. You will have to accept the value your ring is showing (-5-+10) it seems some of the presets werent set up to accept all the proper targets. Mine was rejecting pennies.

 

[Rob (IL)]

Check your vdi disc settings. You will have to accept the value your ring is showing (-5-+10) it seems some of the presets werent set up to accept all the proper targets. Mine was rejecting pennies.

Let us know which program you are talking about. The coin program would not except -5 to +10 but that would not be a mistake. The C/J should except pennies of both kinds. Which VDI were rejected on your detector.

 

[yukonbuck]

Well since rings vary so much I was suggesting that reading the VDI number that the ring produces and then accepting those numbers would allow him to get it to hit. On my VX3 the detector was rejecting my penny so I saw what VDI it was I went in the disc menu and saw it was not accepted. I think it was registering at 56 or so in the zinc range. The CJ would however accept it from factory, it was the coin preset that was not. I did this test in doors and may have had emi or too much metal around which could have caused the lower reading, however I think it was the factory set program that was wrong but it was an easy fix. I prefer the Hi Pro because it accepts many more targets and I can hear the tone and read the VDI and decide for myself. It's a good idea to air test your targets anyway and see the detectors response, right?

 

[Rob (IL)]

Until you find a good solid repeatable beep, don't pay too much attention to the display. Some random display indications are expected and "not of interest". Unless accompanied by a somewhat solid repeatable audio response, all display indication are suspect for being external noise or ground noise.

No need to consult the display until a repeatable audio signal is located, then sweep (its center) several times while consulting the display indication. Pinpointing the target and then sweeping with the center of the coil gives the most accurate reading.

Again, a display indication "without reasonably repeatable audio" is typically not of interest. So go audio first, then consult the display.

[attachment 258376 2013-02-16_182838.jpg]