|
 Field
Test Report
 White's
DFX
by Chris Rogers
Without
doubt the biggest problem facing everyone involved in metal detecting is
the choice of the best detector for their needs. It is the one topic
that seems to lead to more discussion and disagreement in the hobby than
any other.
Let’s take just one point in isolation from the many that arise in
those discussions and, ignoring the cost factor, ask the question
“What is better, a simple ‘turn on and go’ detector or an ‘all
dancing and singing’ state of the art computerised machine?” Put
another way, does the operator benefit from the so-called gadgets on a
programmable machine?
 There
is, of course, no definitive answer to this except to say that, in the
case of the latter, the majority of user programmable detectors do have
the facility to simply switch on and go. This is achieved by using the
factory pre-set programmes, which avoid the need to progress further
into the finer details of the detector’s operating capability. In my
experience very few individuals, once bitten by the detecting bug, drop
out and most are soon looking to upgrade their machine to help their
efforts in the field. The more that is learnt about the other factors
that come into play after gaining some search experience, such as
different soil conditions and the varying conductivity of metals, the
need for greater flexibility soon becomes apparent. The ability to
adjust your machine to these changes can make the programmable detector
appear the more desirable option. Whether the individual chooses to
progress to these options could depend on his or her available finances.
Some years back White’s introduced a new detector onto the market
called the XLT. It was a well-balanced, lightweight machine, with easy
to use pre-set programmes. It also had seemingly limitless operator
adjustments for the experienced detectorist, coupled with a rugged
design and super performance. It is not surprising, therefore, that the
XLT came to be one of the most popular and best selling detectors
available. During its existence a couple of modifications were
introduced, but it remained basically the same machine until last year
when the new dual frequency XLT was introduced onto the market, known as
the DFX XLT.
Having used the XLT for hundreds of hours with great success, I found
that a lot of the criticism expressed by the “turn on and go”
fraternity was brought about by their failure to read and understand the
operator’s handbook, which - to be honest - can appear a bit daunting
at first glance. This, when coupled with the retailer who either through
lack of knowledge of the machine and/or time, fails to go through the
different functions shown on the display screen with the prospective
buyer, leads to a lot of the misconception about the XLT and
programmable detectors in general.
With this in mind I have split my report into two halves. The first part
concentrates on the controls and settings while attempting to clarify
some of the terminology used. The second part will be the actual field
test in which I conducted a number of searches using my own and other
recommended settings in a number of different field conditions. My
report pre-supposes that the beginner has carried out some research into
the basics of detecting and is aware of such terms as “motion” and
“non-motion”, “ground minerals”, “discrimination” and
“sensitivity”.
I have not included a beach test of the DFX but hope to be able to
report back on this aspect of the DFX later in the year.
Physical Description
Immediately on opening the sturdy carrying box the DFX XLT is pleasing
to the eye being well constructed and finished. Assembly is
straightforward and takes just minutes to complete. As already stated,
the owner’s guide can appear complicated especially if you do not take
the time and trouble to study it properly. I cannot stress the
importance of reading this booklet thoroughly so that you are fully
aware of what is available to you and how to go about achieving the best
from your detector.
The detector’s looks have not changed much from the earlier XLT, but
the 9.5in coil is now of the Wide Band Multiple Harmonic type. The LCD
meter panel is mounted at the end of a padded handle and under the meter
is a toggle switch, operated by the index finger. This can be used for
pinpointing and depth screen display. The metal control box, which is
fitted below the armrest, has a hinged compartment in which the drop-in
battery pack is housed. The detector’s power is supplied from either
the re-chargeable type Ni-Cad battery (green decal) pack or eight AA
dry-cell batteries fitted into the (blue decal) standard battery box.
The quarter inch headphone jackplug socket is also fitted in the rear of
the control box.
One of the more obvious changes is the logo on the side of the box,
which now reads “White’s DFX Spectrum E-Series”. Also printed on
the control box is the start-up procedure and a target identification
display scale. On the underside is a “Hot Key” shortcut chart that
enables easy access from the search mode to the most needed adjustments.
Among the less obvious changes are: dual frequency operation, four new
user-designed programmes, adjustable sweep speed, and a digital signal
filtration system.
Set
Up
The
pre-set programmes in the DFX allow the user to push a couple of pads to
begin searching while the detector automatically controls the
adjustments for you. Beginners will find this facility the best option
until they become familiar with the many adjustments that the more
accomplished detectorist will want to access.
Looking at the display panel you will see five push button control pads.
Reading from left to right they are marked: Menu, Arrow (down), Enter,
Arrow (up), On/Off. The detector is turned on by pressing the On/Off
pad, at which point an automatic battery test is carried out. The screen
will momentarily show the battery voltage followed by the main menu. To
recheck the voltage, squeeze and hold the trigger while pressing the
down arrow. When the battery strength becomes too low for proper
function of the detector, the words “Low Bat” will automatically
appear on the display.
The main menu offers a number of choices commencing with “Preset
Programmes”. To access this setting simply press Enter after which a
choice of five preset programmes appear on screen with an arrow pointing
to the first “Coins”. By pressing Enter (a bleep signal will be
heard each time it is pressed) and following the instructions on the
screen to raise the search coil to waist level, press Enter again then
lower coil to ground level. The detector will now be correctly ground
balanced and ready for operation in the Coins programme. While the coil
is held at waist level the DFX’s circuitry is measuring air
temperature and other variables that effect electronic circuits. When
lowered to ground level and the Enter pad is pressed again, the DFX is
cancelling out the ground mineralisation effect (or ‘Ground
Balancing’ the detector). In this and the other four preset programmes
no further adjustments are needed. Nevertheless, any number of control
adjustments are available to meet almost any need or style of detecting.
The last screen to appear will be the search screen, at which point you
will also hear the threshold hum. After sweeping the coil across the
ground listen for a repeatable solid signal and look at the display. The
icon will show what is likely to be below the search head and the VDI
(Visual Display Identification) number can be checked against the chart
on the control box. The SignaGraph section of the screen provides even
greater information. Because this is a motion type detector the search
coil must be kept moving to respond to a target. (See Mixed Mode).
Other
Menu Options
We have already covered the first option on the VDU, Preset Programmes.
The other options are: Basic Adjustments, Pro Options, and Custom or
EEPROM programmes. Within these headings there are a number of settings,
such as RACHET PINPOINT, COARSE GEB, PREAMP GAIN and many others that
may not be familiar to users of different makes of detectors. With more
than a little help from the manual, I will try to explain in detail what
these terms mean.
EEPROM stands for Electrical Erasable Programmable Read-Only Memory,
which is a memory chip that allows the storage of up to four custom
programs despite battery changes and years of storage. These four
“memory slots”, along with the five Preset Programs, add up to a
total of nine programs that should fit just about everyone’s needs.
The four EEPROM programmes can be erased and replaced with your own
custom programmes. Setting them is a simple operation and I will cover
this in the field test part of this report.
The first five Preset Programs are in permanent memory, with a similar
looking name of EPROM (notice that one E is missing for Erasable).
Changes made in these programs will return to factory settings when you
change from one program to another or change batteries. However, if you
have made changes and forget to save them in a custom program before
turning off the machine, all is not lost. With a good battery still
intact, squeeze and release the trigger immediately upon turning the
detector back on, and the circuitry will revert to the last settings
used. Otherwise, settings will revert to factory preset.
Preset
Programs
The following is an explanation of each Preset Program.
Coins - All controls are
set to handle rubbish contaminated areas such as parks, responding to
most coins and larger jewellery. Discrimination is high in order to
eliminate signals from items like nails, foil, ring-pulls, and “hot
rocks”. If possible, though, try to start with a program of low
discrimination, as good items can be missed along with the bad. This is
true for all metal detectors due to various reasons such as the
conductive properties of different metals. This program will save you a
lot of digging in badly contaminated areas.
Coins and Jewellery -
This is similar to the Coins program but with less discrimination. This
means you will receive a few more dubious signals but it is recommended
when searching areas where there is less rubbish.
Jewellery and Beach -
Much like the above, but with settings enhanced to keep the false
signals of salt water from spoiling your searching. Use this one on the
beach where gold jewellery can appear anywhere on the display from iron
through to the silver range due to the amount of debasing that has been
used, as well as the length of time the object has been buried, size,
etc.
Relic - Here the
discrimination is really low to permit the acceptance of all metals
except small iron targets such as nails and some stainless steel. It
separates ferrous/non-ferrous by display indications. However, large
pieces of iron such as nails, horseshoes, broken ploughshares and other
fragments will give a positive signal.
Prospecting - This is a
good program if you are looking for gold. All metals will give an audio
signal, but the only ones to give a VDI (number reading) are likely to
be gold. I personally wouldn’t use this programme much in this
country.
Basic Adjustments
Target Volume - Adjusts
for the loudness of the target signal. Some people believe that setting
this very high will bring greater depth, but this isn’t necessarily
true. Always use a setting that doesn’t cause any discomfort.
Audio Threshold - This
is the continuous background hum. Set it to a just audible level that is
right for your hearing. Again, lots of old hands will tell you to have a
high threshold setting for deeper targets - don’t believe them.
Tone (Audio Frequency) -
Quite simply this means pitch of signal. Set it at a pitch that matches
your hearing. I found the higher range best for my hearing.
Audio Discrimination -
Use the OFF position to detect all types of metals. ON rejects rubbish
with different sounds for different types of targets. Trash goes silent
or gives a clipped sound, while better targets produce a solid sound.
Silent Search - I prefer
to have a very low threshold level but for those people who prefer no
background noise this facility will suit them. Others, of course, like
to hear the background hum, to listen for subtle changes in audio such
as the threshold fading over rejected targets, and changes in ground
conditions. As you might expect, AUDIO DISC is ON, and MIXED MODE is
OFF, during SILENT SEARCH.
Mixed Mode - This means
two modes of operation at once with the ALL-METAL NON MOTION and the
MOTION DISCRIMINATE mode both working together - one accepting
everything and the other discriminating rejected targets. For the
advanced user adding TONE ID and/or VCO will lead to better results.
SILENT SEARCH needs to be OFF and AUDIO DISC ON. Discrimination settings
will give a high or low pitch signal while the All Metal mode will give
all targets a low-pitched signal. Together with Motion Discriminate and
All Metal Non-Motion, Mixed Mode provides a third type of operation.
Discriminate requires coil motion, All Metal does not.
A. C. Sensitivity - Sets
sensitivity for the motion discriminate mode. Along with DC SENSITIVITY
and PREAMP GAIN, this control determines how deep the detector will
search. It should be set as high as possible without causing the
detector’s circuits to become unstable and give false signals
(chatter). Experiment with the ground conditions, adjusting this control
and the Preamp Gain to achieve the greatest depth possible.
D.C. Sensitivity - Sets
sensitivity for the ALL METAL NON-MOTION mode for stability and
pinpointing. Shallow targets pinpoint better with a lower setting. MIXED
MODE and VCO AUDIO are also affected by the D.C. Sensitivity setting.
Backlight - The use of
the backlight can be quite a drain on the battery, and this control
allows you to use as little power as possible. In an improvement over
past Spectrum detectors, the DFX stores the setting in the custom
programs. The backlight is used for searching in poor light. In an
emergency hold the trigger and press MENU to turn it on.
Viewing Angle - This is
a control that adjusts the visibility of the display for various
temperatures. The higher numbers speed up the display to improve
visibility in cooler temperatures, while lower numbers work when
detecting in warmer conditions and in strong sunlight. Again, the
settings can be saved in the custom programs.
Pro
Options
I spent a lot of time messing around with these options and found that
it pays to experiment. More details will be given about this in the
actual field test.
Ratchet Pinpointing -
Pinpointing has always been a very personal operation, although a
detector’s ability to pinpoint a target varies greatly between makes.
How many times have you heard people say that they can’t pinpoint
well? This control does the detuning process automatically. The previous
need to release and then re-squeeze the pinpointing trigger as the
centre of the coil approaches the centre of the target is now done by
the detector, reducing the virtual size of the target. Think carefully
before using this facility as some people prefer to judge the size of
the target before detuning.
S.A.T. Speed - This is
an abbreviation for Self Adjusting Threshold, otherwise known as
auto-tune. It keeps the threshold hum even, which is especially
important when hunting in the All Metal mode or when Sensitivity is
high. Generally, faster speeds are for more mineralised ground, and
slower speeds for less mineralised ground. Without this control the
Threshold would drift due to ground changes, and the trigger would have
to be continually re-squeezed. In relation to types of hunting, slower
speeds are for coin hunting, higher speeds are for beach and relic
hunting, and the fastest are for prospecting.
Tone I.D. - Allows each
V.D.I. (target ID) number to have its own tone. The higher the V.D.I.,
the higher the pitch. There are 191 different pitches used in the MOTION
DISCRIMINATION mode. TONE I.D. comes into its own when using the MIXED
MODE.
V.C.O. - Stands for
Voltage Controlled Oscillator, and that means the stronger the target
signal, the higher the tone pitch. This feature is used in the
non-discriminate modes to aid in pinpointing as well as helping in MIXED
MODE. The D.C. SENSITIVITY setting has a direct effect on V.C.O. In
pinpointing, when you hear that pitch at its highest, you know you are
over the centre of a target.
Modulation - This
control determines whether the motion mode gives a strong signal on deep
targets, or a soft one. ON gives lower volume deep responses; OFF
supplies the same volume regardless of how deep the target lies. When
experiencing faint signals, which could mean deep targets and possibly
older finds, this control may be of help,
Autotrac - Automatically
keeps the ground balance setting adjusted while you hunt. The importance
of precise ground balance cannot be over emphasised. The only time you
would want to turn this OFF is if you are over a lot of rusting,
man-made iron. Be aware that TRAC INHIBIT affects AUTOTRAC.
Trac View - The word
TRACK appears on the display when AUTOTRAC adjusts the ground balance.
Preset to OFF, it should really be kept ON to be certain that you have
the correct TRAC SPEED setting. When TRACK appears often on the display,
it could also mean bad ground mineralisation.
Trac Speed - Determines
how often AUTOTRAC regulates the ground balance, by setting how much
change in mineralisation is needed to cause an adjustment. Slower speeds
equal great change; faster speeds equal minor change. Excessive tracking
can cause ground balance errors, and too little does not keep up with
changing ground. When TRACK is seen appearing every three to five coil
sweeps, the TRAC SPEED is correct.
Trac Offset - This
feature is intended to be used by experienced searchers to track
mineralisation either of the extra negative or positive type. Small
metal targets such as gold nuggets in heavy mineralisation would benefit
from a slightly positive setting, while a slightly negative setting can
help reduce “hot rock” signals.
Trac Inhibit - Use OFF
for prospecting and ON for most other detecting situations. It prevents
Autotrac from tracking the ground while the target is detected. ON
reduces the tracking to corrosion of most metals. Since gold does not
corrode, OFF is automatic in the PROSPECTING Program.
Coarse G.E.B. & Fine G.E.B.
- This is for manual ground balancing. Those who opt for manual ground
balance over the exceptionally good automatic ground balance already
know what they are doing. With 255 settings, COARSE is for large
adjustments, while FINE is for small ones. There are times when manual
ground balance can be useful, but the large majority of users will
choose the DFX’s automatic ground balance.
Disc. Edit - Permits
setting each V.D.I. Number to be accepted or rejected by the
discrimination with no apparent loss of depth while using
discrimination. Be aware, though, that the more V.D.I. numbers are
rejected, the greater the possibility of rejecting good targets. The
best advice is to keep discrimination as low as possible, thus accepting
the widest range. V.D.I. numbers (Target ID) can be accepted or rejected
from -95 to +95. While +95 is often associated with a “hot rock”, it
is best to dig if it indicates a deep target on the display.
Block Edit - Allows the
user to change the accepting or rejecting of larger groups of V.D.I.
numbers by dragging ACCEPT or REJECT, using the ARROW controls.
Learn Accept/Reject -
This feature is useful when your program is all set and working well,
but you keep encountering one specific type of trash. Select LEARN
REJECT and sweep the coil over that junk until the signal disappears. On
the other hand, if you were hunting for one specific item - say, a lost
earring - you could reject everything, and then LEARN ACCEPT that one
signal by running the other earring under the coil. Don’t forget to
turn LEARN off, or the detector will be learning to reject or accept
everything the coil passes over.
Recovery Speed - This is
the time it takes your detector to recover from the last target before
it can respond to the next. Faster speeds work best for trashy areas.
Use slower speeds for cleaner areas and better discrimination. The
faster speeds are also good for separating closely spaced targets, but
you will reach a speed where depth and the sounds of discrimination
begin to suffer. A speed just below this seems to work the best.
Bottlecap Reject - Sets how well the detector rejects iron. A higher
number causes more broken sounds on iron targets and thus makes them
easier to identify. Set it too high, though, and good targets will start
to sound bad also, and iron next to a good target will lose both. Start
at preset and experiment from there in the area being hunted.
Hot Rock Reject -
Determines the responses to those rocks with a different mineralisation
than the surrounding soil. A +95 V.D.I. reading is often a hot rock, but
it can also be a deep good target, as noted earlier. This control allows
a range of rejection or acceptance of this V.D.I. number. Instead of
just accepting or rejecting +95, one can run a range from 0 to 20. Zero
accepts +95 while 20 rejects it. This control provides many areas in
between to help give the hot rocks a different sound than real targets.
A negative hot rock is also called a “cold rock”, and the response
will disappear in pinpoint. A positive hot rock will continue to respond
in pinpoint mode. This control could be invaluable in an area with
similar hot rocks.
Sweep Speed - If you
need to move quickly, a higher speed is indicated. Conversely, if you
need to slow down, a slower coil movement is needed. Faster speeds could
be effective in a competition hunt or when you want to cover ground
where targets are fewer. High-trash areas will cause you to slow down,
so a slower sweep speed is best at those sites, or anywhere you need to
do a slow search. Sweep speed is more important than the casual
detectorist would think, so a little more time has to be spent here.
Sweep Speed is related to Recovery Speed and Ground Filtering, and that
relates to depth and discrimination. Basically, a faster sweep goes with
faster Recovery speeds, and vice versa. Some people like to swing the
coil fast, and some slow, never realising that speed affects the depth
and discrimination ability of the detector. A nice feature on the DFX is
this ability to set your own speed. I also mentioned GROUND FILTERING,
and we will get to that in the next section. However, you need to know
that the sweep speed of the DFX is not adjustable when using two
filters, as the detector does that for you. On the other hand, when
using three to six ground filters, you can set the speed yourself if
desired. Too fast a Sweep Speed and it will get ahead of the Recovery
Speed, but you don’t want it too slow either. It’s a matter of
choosing the right width of target signal that the circuitry analyses.
You want a Ground Filter, Recovery, and Sweep Speed that will give you
the best depth and discrimination. A bit of experimenting will reveal
the ideal speed for your preference and type of hunting. If you don’t
have a test area already, bury a few coins away from each other in clean
ground and at various depths. Make all your settings and then try
various sweep speeds to see which provides the best performance.
At this stage it is good to remember, that all these things are for
people who want to tweak up the DFX’s performance. If you are new to
the hobby, don’t get mind boggled. Just let the detector do the work
in the Preset Programs.
Ground Filtering - As
stated earlier, the DFX offers a choice of up to six filters! What does
that mean? Well, it means versatility. It means that you can use the
same machine for both coinshooting in parks and relic hunting in extreme
ground. The two filters will provide a quicker response to separate
closely spaced targets in a trashy area, while the four, five and six
filters will better handle mineralisation - and that means more depth.
White’s use this number system to let you know that as the level of
mineralisation goes up, the depth penetration goes down with the lower
number of ground filters being used.
Visual Disc - When this
feature is on, rejected VDI numbers and ICONS are prevented from
appearing on the display. This keeps the display cleaner for
interpreting other information.
Icons - The ability to
look at the display to see the graphic representation for a ring pull,
nail, screw cap, foil, or various coins is good. It can speed things
along as you walk. However, it does slow down the display for other
indications, which in turn slows down how soon you go to the next
target.
V.D.I. Sensitivity -
This determines the strength of response of a target required to cause a
display indication. It can also provide a third digit to the VDI number
when set to 86 or above. A lower setting brings fewer and more reliable
indications to the display, but may also keep deeper targets from
registering. A higher setting brings more indications to interpret. Try
listening to signals first, and then look at the display to isolate a
good target.
D.C. Phase - Those
people who set their own manual ground balance will find this of use.
When the coil is stopped over a target or ground, the D.C. PHASE is
shown in the display.
Accumulate, Average, & Fade
- These three controls are listed together for convenience. With
ACCUMULATE turned ON, SignaGraph information is gathered from multiple
coil passes. OFF shows information only from the last coil sweep.
AVERAGE is best used with ACCUMULATE to reduce indications from strange
loop or target angles. AVERAGE does what it says, it “averages”
received information for the SignaGraph. FADE is the rate at which old
information is cleared from the SignaGraph. With up to 14 settings, you
can easily choose one that allows enough time to view the SignaGraph
info before it is reset.
Preamp Gain - This was
commonly known as “signal balance” on older machines. It is very
important to the depth capability of the detector. Like Sensitivity, it
needs to be set as high as possible without causing circuit instability.
Unlike Sensitivity, however, it has a great influence on OVERLOAD.
Overload should not be appearing in the display during searching.
White’s limit the PREAMP GAIN settings from 1 to 4. Get it as high as
possible without OVERLOAD. One thing to remember is that every time
PREAMP GAIN is changed, the detector needs to be re-ground balanced.
Multi Frequency Method -
The DFX provides four choices in operating frequencies: two Frequency
Best Data, two Frequency Correlate, one Frequency 3kHz, or one Frequency
15kHz. Only one of these can run at a time. The DFX is offering a choice
of frequency settings and not limiting you to what the manufacturer
provides. No one choice is best for everything. Gold responds better at
higher frequencies, while silver and copper respond better at lower
frequencies. The 3kHz option is great for high iron content black sand
when salt is not present, and gives better depth on higher conductivity
metals like silver. The 15kHz works well in lower mineralisation without
salt for gold and cupronickel range targets. Multi Frequency operation
does a great job in areas with magnetic iron and conductive salt. The
term “BEST DATA” can be misleading as one of the two choices in
multi frequency. It suggests that it is the “best” method to use,
and while that is often true, it is not always the case. CORRELATE
compares data taken from both the 3kHz and 15kHz and rejects those that
do not offer predictable information. For instance, iron does not
compare predictably between the two frequencies, and thus this method
would provide good iron rejection. The BEST DATA multi-frequency method
transmits and processes data at both frequencies just as Correlate does,
but then automatically chooses to accept the data from the most
reliable. Both multi-frequency methods eliminate salt signals. BEST DATA
is the preferred method for most applications.
V.D.I. Normalisation -
Using two frequencies changes where targets show up on the normal VDI
scale. The DFX is automatically set up to account for this when using
one of the multi-frequency methods. But when using one of the
single-frequency methods, the calibration is different. With
NORMALISATION ON, the circuitry recalculates and displays the normal
V.D.I.s we are all used to seeing with the 6.59kHz. When OFF, the
display becomes distorted in that the “Silver” end is expanded and
the lower end compressed when using 3kHz, while just the opposite
happens with 15kHz. This expanded resolution presents a bonus when
seeking specific targets - for example, looking in the “nickel-foil”
range for differences between gold jewellery and aluminium.
As previously stated, please don’t get hung up with all of the
foregoing. The purpose of going through the individual details of the
DFX was simply to take some of the mystery out of the settings available
as well as to show the potential of the detector. Having gone through
all of the technical data, there’s nothing like using a detector for
the real answers and I have tried to do this in the second half of the
report. Just as a taster, after experimenting with some of the
adjustments, I found 127 non-ferrous finds in just four hours detecting!
Previous
or present owners of XLTs will be familiar with most of the programmes
and, with this in mind, I will be concentrating on introducing the
newcomer to the programmable world of the DFX. For those experienced
users who are looking to improve the performance of their machines I
hope that I can give them some ideas that have helped me over the past
few months. I also found that there is a whole mass of information
concerning the DFX on the Internet, including some revised programmes
that may be of assistance to the advanced user.
Getting To Know The DFX
I make no apologies for stressing again the importance of reading
and re-reading the manufacturer’s handbook that is supplied with the
DFX. It is laid out in an easy-to-read format and follows a logical
sequence of directions covering all of the detector’s functions.
Failure to do this could lead you to not fully understanding the
detector’s capabilities and not benefiting from its advanced
technology. Although I had previous experience of using the XLT, I spent
several hours shut away from any distraction with the new detector and a
selection of coins and other metallic objects. I went through the basic
adjustments with the aid of the handbook, familiarising myself with the
controls and readings on the display panel. When you have also done
this, spend the first few weeks getting used to the feel and responses
of the detector in the preset programmes.
In field use one of the most important things is to get the balance
right. I found that I had to keep putting my thumb across the control
buttons to counteract the weight of the coil because I hadn’t adjusted
the shaft to a suitable length. Don’t dig your targets until you are
sure that you understand what the display is telling you, and try going
through all the basic adjustments until you find the ones that are right
for you. Get used to reading the screen and practise your pinpointing
techniques. Use the trigger to determine the depth of the target and,
most importantly, keep your battery fully charged. Avoid progressing to
the Pro options until you have this experience and confidence.
First Moves
I live and detect in the north of East Anglia. While there are some
excellent sites in the area and some good finds to be made here, the
soil conditions in this part of the country are, to say the least,
extreme. You have to work your detector hard to achieve any sort of
result. The soil is sandy and light but is very heavily mineralised. My
experience has shown that getting the correct adjustments to the machine
is vital. The five factory preset programmes in the DFX are very good
and will locate most targets, but in my opinion they are not totally
suitable for British conditions. Certain alterations need to be made -
especially in the discrimination department - if you are serious about
finding the smaller objects such as hammered cut halves and quarters.
With this in mind, and before any testing of the DFX, I looked through
the Custom EEPROM Programme settings and decided that the EEPROM Hi Pro
most closely matched the conditions I was going to be searching in. I
started my tests without any adjustments except to the Tone ID. I prefer
to operate with this in the “Off” position, relying on my experience
to determine the difference between the signals received rather than the
detector’s varying tones with it switched on.
Tests
I learnt a long time ago never to worry about the large targets; if a
detector is picking up the small ones it will certainly pick up the
larger ones. I carried out a number of tests that I have used over the
years when assessing a detector’s “in air” performance. Using a
Henry VI farthing, an Edward III cut halfpenny and a small gold ring, I
received a clear and precise signal from all of these items in this
programme varying in distance from 3-5in from the search coil. I have a
large, heavily mineralised rock that I use when purchasing a new
detector. I am confident that if a machine can find a hammered coin
under this, then it will perform well in the field. It is surprising how
many of the upper price range models I tried failed this test, and I
looked forward to seeing how the DFX would cope.
With the discrimination set to reject iron the DFX picked up the cut
half with a “broken” signal but failed with the ring and farthing. I
then put a full hammered penny under the rock and it was picked up this
time more clearly.
Moving out onto the fields with the same settings, I was happy in the
knowledge that the DFX could cope with the soil conditions. I tried it
firstly on pasture with little finds of interest to comment on. It was
noticeable, though, that I was not picking up any ferrous material.
The second site was mineralised with the added burden of heavy iron
infestation; it had also been previously detected on for around 20
years. The soil was freshly ploughed, with the rough furrow pressed and
very wet. In fact, these were not very nice conditions to be out in.
However, I found a Georgian silver seal matrix at about 6in and this
gave me the necessary boost to carry on.
Overall, my reaction to the DFX was that it was marginally better than
the XLT. But it was not what I was looking for on my difficult sites,
even when tried in all the suggested programmes and settings posted on
the Internet. However, I did have an ace up my sleeve. I had been given
a tip off that White’s had a 10in x 5in elliptical coil available as
an accessory to be used with the DFX in poor ground conditions. I
purchased one and fitted it to the machine.
Before trying the DFX with this different coil and using the experience
gained from the initial testing, I decided to carry out a few minor
adjustments to the basic settings of the preset Prospecting programme.
The settings of the programmes are to be found at the rear of the
handbook in Chapter 5.
Basic
Adjustments To The Preset Programmes
As already mentioned, the Prospecting programme settings are most
suitable for searching in the mineralised and very difficult conditions
described above; but they do need some minor changes. To fine-tune this
programme (shown on page 55 of the handbook), I would suggest the
following procedure:-
- Set
the volume, tone, sensitivity and threshold levels to your personal
preferences.
- Turn
the Audio Disc ON (the prospecting programme is set for gold
searching and therefore needs to be off).
- Scroll
down to Pro Options and alter Auto Track speed from 18 down to 8 or
9.
- Continue
to scroll down to Bottle Cap Reject and increase it from 1 to 3.
- Go
to Rock Reject and adjust to 10.
- Sweep
Speed should also be increased to between 12-15.
- Scroll
on to Pre Amp Gain and adjust to 3.
- Most
importantly go to 2 Frequency Best Data and turn it ON - this will
automatically turn 1 Frequency off in the original programme.
This
is all that I feel is necessary to match our bad British conditions, and
as you become more familiar with the detector it may well be that you
can make even finer tuning pay off. Remember, though, that these
settings will only remain as long as the machine is turned on; when you
switch it off the alterations will be lost and the detector will return
to the factory settings.
To store the changes to the programme it is essential that they are
transferred to one of the EEPROM Programmes. To do this after making the
adjustments do not turn the detector off. Press Menu, which will take
you to the preset programmes. Press Enter and using the down Arrow
scroll down until you reach the Prospecting programme; this will have a
flashing cursor next to it. Carry on scrolling down until you reach any
of the EEPROM Programmes and press Enter. The screen will indicate a
flashing cursor at LOAD. Do not press but continue on to SAVE. Press
Enter again and your personal settings will be saved safely for you to
recall anytime after switching off.
Tests
With Elliptical Coil
Using the same “in air” and “below the rock” tests with the
elliptical coil the DFX picked up all the test pieces with ease. To say
that I was astounded would be an understatement. These were the best
results I had achieved with any of the machines I had tested, and
transformed the DFX in my view from a top range detector to the top
detector.
Over the same ground that has been the graveyard to many machines, I
located 127 non-ferrous finds. These included buttons, musket balls,
pieces of lead, a medieval thimble, jettons, some hammered silver and
two personal seals. This was all in four hours of detecting! Depth was
excellent. I found a hammered penny at a measured 9in, and musket balls
at depths of up to 10in. The discrimination was very good and I dug no
iron at all. On three or four occasions I had doubtful two-way signals,
but these were easily identified as iron on the SignaGraph display.
The
detector was very sensitive to the very tiny finds, which it identified
at good depths. Pinpointing was very easy with both coils. One
interesting fact was that even in the factory preset coin mode the DFX
rejects modern iron centre copper clad 2p and 1p coins.
There are few faults with this detector, and those that exist are more
than made up for by its performance. In certain configurations it is
sensitive to high-tension electricity cables. On two occasions it also
switched off without warning. The other more familiar “bad” design
features of the XLT are still obvious: the control box and battery
housing are at risk of damp when the machine is rested on the ground and
the display screen is prone to scratching; as a result you really need
to purchase covers for both of these components.
Summary
Going back to the original theme of which is the better type of machine
- “turn-on-and-go” or user programmable - the question becomes
redundant when talking about the DFX. Here you have a simple
pre-programmed detector that can be up and running as soon as you get on
site. At the same time it is a machine that can be adjusted to meet the
most demanding of circumstances. Even when using the Pro options that
have been stored in the EEPROM settings you still turn on and go!
My intention was to take some of the mystery out of the technical side
of the DFX, and I hope I have achieved this aim. It is not a difficult
detector to use provided you read the handbook. Sit with the detector
and handbook, and go through each stage again and again until you
understand what you are doing. Don’t attempt too many changes at once,
as you will not be able to tell what differences the changes have had on
performance. Go out with the intention of concentrating on certain
aspects of the settings rather than trying to achieve perfection all in
one go.
My suggestions as to the setting up of the detector are just a start,
and I’m sure that you will rapidly become competent in achieving the
right settings for your personal conditions.
I think that White’s should give you the option of either the 9.5in
concentric or the 10in x 5in elliptical coils when the DFX is first
purchased. I can see a use for both but in my book the elliptical coil
was the winner.
Although the DFX is priced around £850, this is money well spent
and there will be no need to upgrade at a later date. I still have a
long way to go with the DFX - experimenting with the frequencies for
example - and you will find the same. Therefore be patient. I am fully
aware that the cynics will say that this is another “be kind to the
manufacturer” report and that I have exaggerated some of my comments.
But I can assure you that I have never written a field test before,
neither have I had any contact with White’s. I have written about
the detector as I found it….there is no point in doing otherwise.
©
2005 Reproduced
here (with text amendments) by kind permission of ‘Treasure Hunting’
magazine
click
here to
go to the White's DFX Metal Detector
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