White’s Electronics MXT 300 User Manual

Page 12

Chapter 4 MXT 300 Display

Prospecting MODE

The Prospecting MODE changes the display infor-

mation signiﬁ cantly.

Gold in it's natural state can be any size and shape

from very tiny pinhead size ﬂ akes to large placer

gold nuggets as well as veins of various size in

quartz rocks. The Prospecting MODE takes these

facts into consideration and changes the display

accordingly. When prospecting an operator must

expect to dig nonferrous (not of iron) trash metals

such as aluminum foil, lead, and small brass. Any

of these metals can and do elicit the same response

as gold and MUST BE DUG. Attempts should be

made to avoid only IRON targets and only when

possible. The MXT 300 displays information which

is intended to help the user determine whether the

target is NON-IRON (dig) or IRON (don't dig). In

heavy mineralized ground tiny pieces of gold can

sometimes look like IRON to a metal detector and

small pieces of IRON can look like gold. The VDI

numbers and Iron Probability scale both provide

help in determining when to dig.

The Prospecting MODE provides four signiﬁ cant

display indications.

1. VDI - The VDI number is listed on the display

and referenced on the label below the display. Gold

can indicate anywhere from slightly negative to +80

on the scale, however, most small nuggets indicate

in the -20 to +40 range. Metals that indicate above

+80, or below -20 are highly unlikely to be gold

unless they are conglomerated with highly unusual

alloys. If the VDI number tends to jump back and

forth from small negative numbers to small positive

numbers it is usually a small piece of some metal

and should be investigated by digging. Remember,

small ﬂ akes of gold in bad ground can read into the

small negative range. A magnet on your digging

pick can sort out a small shard of iron quickly.

2. IRON TARGET? - Indicates the likelihood the

target is ferrous (iron) expressed in a %. This indi-

cation can be different in different areas depending

upon the degree of mineralization. As a general rule

targets registering 60%, 70%, 80%, 90% are going

to be iron. 80% and over will produce the audio

grunt in the primary (Trigger Center) mode. Targets

that register 10%, 20%, 30% or 40% are going to be

gold or (lead, copper, aluminum, brass). All targets

registering 50% or below should be investigated.

As mentioned under the VDI section, iron ground

mineralization can distort the way the detector re-

acts to gold. It is always a good idea to place a test

nugget just under the surface of the ground where-

ever you are going to be prospecting and note how

it reacts to the IRON TARGET %. This will give

you a gauge as to what to expect. The degree of de-

pendability is affected by ground minerals and the

size of the target. It is not uncommon for a small

piece of gold in very bad ground to read 70% prob-

ability of being iron. Remember when in doubt...

DIG. Use both the VDI and % IRON PROBABIL-

ITY. Dig often at ﬁ rst, till you get a feel for the area

and accuracy in that ground.

NOTE: The display reading above would indicate a
target with a proper VDI number for gold and a low
enough iron target percentage to dig.

Mode toggle
switch Down for
Prospecting