22) What does the VDI reading
in prospecting mode really mean?
The
VDI reading is a separate reading from the iron probability output. It is also different from the audio
output. The nugget shooter working with
the MXT needs to learn to use all 3 pieces of information.
Many
small nuggets give no VDI reading at all - their signal response is so small,
the MXT cannot do the analysis needed to calculate a VDI reading. The manual says that small gold nuggets may
give a VDI from -20 to +40. Large
nuggets may give VDI readings from 40 to 80.
Items above 80 on the VDI scale are unlikely to be gold, but still may
be well worth digging (hey, even prospectors drop coins once in a while).
23) What is the best coil
sweep speed for coins and what is the right speed when hunting gold?
The
MXT is not as sensitive as many other detectors to the coil sweep
speed - which is very beneficial to new users as this is a critical item for
many other detectors, but is simply not much of a big deal for the MXT (with one exception - gold nuggets). Because of its quick target response, it
works just fine for coin shooting or relic hunting at a wide variety of coil
movement speeds. As a result, many folks
learn to work their MXT quickly through parks and
schools, as it tends to increase their finds.
However, this does not hold true when prospecting for gold - this is a
case where one needs to go slow or nuggets will be missed - especially the
smaller ones. Slowing down a bit can
also help find the deepest coins near the limit of the detectors ability.
24) Can the VCO pinpoint mode
be used to pinpoint gold nuggets?
The
VCO pinpoint available by pulling the trigger in coin shooting or relic modes
can be used to pinpoint if the gold nugget is large enough. It doesn’t have to be huge, but nuggets below
about 1.5 to 2 grains don't respond well to the VCO pinpoint. Excessive iron in the ground can also cause
problems, but it sometimes it is possible to pick out a target even through
this type of condition. It is far easier
to pinpoint in VCO mode than the regular prospecting mode, and it is easy to
flip from one mode to the other and back again, so its
worth giving it a try.
25) Can the Relic mode be
used to hunt gold nuggets?
Some
folks do prospect with the MXT in relic mode as the two
tone system is easy to use. You do lose
a slight amount of depth, and/or slight sensitivity to small nuggets, but the
loss seems to me pretty slight. Getting
an ID for iron is fairly reliable in relic mode, but the VDI does not tell any
difference between lead or gold - in spite of what the
possible target ID might be saying. You
can get gold nuggets with the same VDI numbers as you might for lead shot,
bullet casings or bullets. The smallest
and deepest gold will not produce any VDI score at all (as the max detectable
depth is slightly deeper than the depth the ID system will work). It is my opinion that relic mode might be
better for prospecting when you are in an area with a very high amount of iron
trash, where the ability to actually discriminate out iron would be needed. When using discrimination while prospecting always
be sure to set the amount of discrimination very low,
or small nuggets can be accidentally eliminated.
One
of the things you can do to try to get the best of all worlds is to switch
modes. One can hunt in prospect, then
when an interesting target is found, switch modes and see what the other modes
say about the target before digging. The
coin/jewelry and Relic modes also offer VCO pinpointing which is handy if your
nugget is large enough to respond to the VCO mode.
26) What about rechargeable batteries?
Although
Whites offers a self-contained rechargeable battery system for the MXT, I have been using NiMH batteries since
I got my MXT and they work just fine. I
get about 20 hours of operation per charge.
If you only use your detector once in a while, it is probably not worth
it to buy the rechargeables, but if you use it at
least 5 or 6 hours per week on average, its worth it
to get them. If you use your detector
often enough, the rechargeables will save you a fair
amount of money.
27) I was running my MXT and the screen
suddenly went completely blank. What
should I do?
A
small percentage of MXTs seem to have this problem
once in a while. I had this problem
intermittently with my MXT, however, after doing it about
25 times over a month or so, it stopped. I
never sent it in, and I have not had it happen even once in the months since,
though I have used it regularly. It
appears to be a contact/connection problem which can be cured by re-seating
some of the ICs. If it gets bad enough
to be worth sending in, it can be easily fixed by Whites. Otherwise, if it only happens once in a great
while, just turn it off and turn it on again - re-booting the computer system
cures the problem.