mxt usage

Iam using the mxt all the time now,nothin fantastic as other users report ,but it goes deep,finds very small items and i am getting more comfortable using it.My question is,why am i finding nickles between 18 - 24 range I thought the machine would be more exact. Rusty nickles read differently and can be anywhere in that range at least on my machine.It may be the 6x10 i am using.I am looking for gold in all the wrong places.All i need to do is dig everything,which is an awlful lot of work,i'd be better off getting a job and buyin it 8/

BOWSER link=topic=6457.msg75386#msg75386 date=1310957112 said:

My question is, why am i finding nickles between 18 - 24 range I thought the machine would be more exact.

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Before I throw my $0.02 worth into your question, let me editorialize a bit and ask why you care? The 18-24 normalized VDI range is where much of the higher carat gold jewelry resides anyway. I always dig anything in that range. If it's a nickel...okay. If not...even better.

Like you, I've pondered the 18-24 range question a bit myself. Here are a few thoughts I've had over the years.

I have an older MXT (not the Pro) which I hunt exclusively using Alternate Relic Mode (not available on the Pro model) with a 6 X 10 coil. In ARM, my MXT reads a post-war nickel at VDI of 18 about 95% of the time. However, I know several folks whose older MXT's will read nickels at 24 about half the time. (Please remember that 18-24 is really only a span of four VDI readings, as the numbers are only even.) I attribute my results to the fact that I hunt at very high gain...the edge of insanity.

Remember that the VDI scale on all White's machines is based on the original (XLT) operation frequency of 6.67KHz, and ALL other machines are normalized to this scale. Normalization is simply a mathematical computation that occurs within the firmware of a particular machine. Different operating frequencies (above and below 6.67KHz) will tend to yield normalized VDI ranges that vary slightly from the original...mostly due to the math.

For example: The 15KHz (MXT operating frequency) normalization process widens the VDI separation for gold targets...giving the user a wider range for gold targets while narrowing the separation of coins. On the other hand, a frequency of 3KHz (below the 6.67KHz standard) will widen the separation of coins and narrow the gold VDI range.

From the above, we can see that operation frequencies closer to the XLT's 6.67KHz will tend to be better all around machines and not show the variation such as your nickel example. However, gold (being a low conductivity target) responds better to frequencies much higher than 6.67KHz (My Gold Bug II operates on 71KHz). The MXT's 15KHz is a compromise that leans toward the higher (gold) frequency. It's still within a reasonable VDI range for all-around hunting, but the user has a better range for gold targets.

(OBW: If the VDI is a solid 8...DIG IT!!!)

Thanks so much john, my fear was, not being a very smart individual, i was thinking the detector had developed a slight problem.I am the kinda guy that can't tell a hammer from a drill press.Thanks for all you're help.Idig all 8 vdi's and so far i only get siver foil discs. all my best jim

The VDI=8 advice was given to me by a good friend when I first started using an MXT. Like you, I've dug a lot of foil, but have several nice pieces of high-carat weight jewelry that have hit hard at 8.