Using Non-Normalized Settings to Discriminate Out Junk...

[Neil in West Jersey]

One of the best (and most overlooked) features of the V3 is its ability to discriminate out junk. With a little tweaking you can enhance its ablility to pass over junk items that are a nuisance while reducing the risk of passing up good targets. This is because the V3 has the ability to expand the VDI scale in the jewelry and junk range. This is accomplished by the following easy steps:

1) Change the frequency setting from Multi Frequency, Best Data to 22.5 Khz.

2) Uncheck the box marked "Normalize"

By unchecking the Normalize button, the VDI scale in the lower end where gold and junk targets are typically found is expanded.

For example, Jefferson Nickels and "peel off" pull tabs both respond with a VDI of 19 when using Best Data. By changing the frequency setting to 22.5 KHZ and unchecking the Normalize box, the VDI of the Jefferson Nickel becomes 58, while the pull tab now responds with a VDI of 46! If you are tired of digging those "peel off" tabs, you can safely discriminate out 46 VDI without risking passing up the nickels.

There are a few things to keep in mind though:

1) You will need to learn a new VDI scale. Normalized data automatically changes the VDI numbers to the 7.5Khz scale, which is the White's standard. Non-Normalized data is displayed in its "raw" form. VDI numbers are different in each of the three frequencies and are not modified to the 7.5Khz scale.

2) While the range is expanded in the lower end of the scale, it becomes compressed in the upper end of the scale. Dimes, quarters and pennies become more difficult to ID. By changing the the frequency to 2.5 KHz, Non-Normalized, the opposite becomes true. The scale is expanded in the silver/copper range, and becomes compressed in the gold/jewelry range. This increases the resolution for silver and copper coins. It now becomes easier to distinguish silver from clad. For example a clad and silver Roosevelt Dime typically respond with VDI numbers ranging from 76-80, a difference of 4. By non-normalizing the data in 2.5 KHz, the clad dime's VDI becomes 50, while the silver dime's VDI becomes 56, difference of 6!

3) By discriminating out ANY VDI numbers, you always run the risk of discriminating out good targets. Gold Jewelry can fall anywhere from the negative numbers all the way up to the coin range. It is a gamble, but in areas where there is an abundance of pull tabs, non-normalized data can make the metal detecting experience more enjoyable.

For a chart showing how different targets respond in each frequency in both normalized and "raw" VDI numbers, click here

 

[earthmansurfer]

You guys really have a flexible and powerful detector there. I bet there are so many things that the manufacturer did plan on the detector being able to do, but leaving it so open will allow detectorists to discover some interesting uses.

I checked out your spreadsheet and it's really nicely done. It makes a lot of sense, for example, if you are hunting for silver to run it in 2.5Khz and make sure the data is non normalized. But not just to have better ability discriminate out the junk, but as you said to increase that end of the scale. Wow!

I'm in Europe and most of the coins I dig seem to hit at 57-61 but I know that it is compressed at this range. They probably designed my Omega to be more open at the upper range of the scale. I'm really looking hard at your V3i and with winter on the way I have time to think. I've been reading the manual quite often and am amazed at the flexibility (but also overwhelmed by how complex things can get). I guess using some tried and proven programs would be the way to go. We have heavy iron here so the needs of European detecting is slightly different than over in the States.

Keep the good ideas coming and good luck.

ps - Any word on them creating an emulation program for the pc? It seems like it would be easy since the V3i is basically running it's metal detecting program as software.

 

[Neil in West Jersey]

ps - Any word on them creating an emulation program for the pc? It seems like it would be easy since the V3i is basically running it's metal detecting program as software.

I know at one time there was talk about a dongle, but I think the plan was scrapped. They also dropped the wireless transfer feature that was on the original Vision and V3.

 

[earthmansurfer]

Doing a usb connection for patches, upgrades and transferring programs would have been too easy. It makes me think they left it out for other reasons. For example since the V3i is software based and not hardware, perhaps they were worried what people would do if they had that kind of access?