Garrett Infinium LS Pulse Induction Metal Detector
The Garrett Infinium LS (Land & Sea) was introduced in 2002
and is still currently in production. I have a particular interest in
the Infinium. I am a metal detecting fanatic, and one thing I want to
see is better technology, and I believe the best way to get that is
through good old competition. Although Minelab makes fantastic ground
balancing pulse induction metal detectors (the SG/GP series) I was
frustrated by the fact that the U.S. manufacturers were bringing nothing
to the table to compete. It seemed to me they had totally ceded that
portion of the market to Minelab.
I was therefore very happy when I was contacted by Garrett
Electronics Engineer Brent Weaver about testing a new metal detector
prototype in Alaska. The prototype was the soon to be Garrett Infinium
LS. Brent wanted to know where we could go where there was really bad
ground mineralization so that he could test the unit. We took the unit
to the Petersville district north of Anchorage, where there is both
highly mineralized bedrock and some very nasty graphitic slate hot
rocks. The Infinium handled both with ease.
I was impressed and was an early adopter of the unit. It
unfortunately was over-hyped prior to release and faced some backlash
from those expecting a "Minelab killer". Eventually the hubbub subsided
and the Infinium has now found a niche as a very versatile ground
balancing pulse induction detector with good performance at a very
reasonable price. What makes the machine remarkable is that it is
waterproof to 200 feet if you get the optional submersible headphones.
Rare also in underwater units is that the Infinium has interchangeable
search coils by way of a watertight connector. Most underwater units are
hardwired with a single coil, limiting their versatility. Obviously the
Infinium can be employed in environments far more adverse than most
I had a lot of success using the Garrett Infinium gold nugget and
jewelry detecting and have several stories about the unit at
Mining Journal. See
Garrett Infinium in Hawaii,
Garrett Infinium at Moore Creek, and
Coin Detecting with the Garrett Infinium. I also published a lot of
tips on operating the unit that are detailed below the specification
Download the Garrett Infinium LS Instruction Manual Here
|Garrett Infinium LS Technical
|Manufacturer Suggested List Price
||Ground Balancing Pulse Induction (GBPI)
||730 Pulses Per Second
||Tracking (Slow or Fast) and Fixed
||Dual tones plus Adjustable Pulse Delay
||Supplied headphones have volume
||One turn control
||One turn control
||Proprietary headphone socket (No
speaker) Headphones supplied
||Yes, holster provided
||14" x 10" DD
||Seven accessory coils available
||8 AA rechargeable and disposables
||10 - 15 hours
||Waterproof to 200 feet (requires
optional submersible headphones).
||The only scuba capable ground
balancing detector currently available from a major manufacturer
Technical Specifications - Detailed notes about the specifications
listed in this chart.
The Garrett Infinium is a very simple
detector to operate, but here are a few tips to help give you a head start.
These are unofficial tips based on my own personal use of the Infinium for
detecting gold nuggets, jewelry, coins, and relics.
First, here is a suggested starting procedure. Make sure the headphones
are just slightly above the minimum setting. The Infinium puts out a very
strong audio. Set the Discriminate control at “0”. Set the Threshold about
“4”. Turn the Power on and set to the Slow ground tracking position. The
machine should beep 4 times indicating fully charged batteries, three times
if less charge, two times if low, once, you’d better replace right now.
A continuous tone indicates the batteries are below operating condition.
No sound? Check your stereo/mono switch and volume controls on your headphones.
Wave the coil over a target and adjust the headphones for a comfortable
sound on the loudest targets. Then tweak the threshold for a barely discernable
Pulse Induction (PI) detectors have extremely sensitive receiver circuits.
This means that they are much more prone to picking up outside electrical
interference than standard metal detectors. This interference can be from
power lines, substations, radio transmitter, lightning, and other metal
detectors, to name a few. In populated areas some kind of faint sounds and
intermittent signals are inevitable. Some areas can be virtually unsearchable
due to interference.
Garrett Infinium Controls
There are several solutions to the problem. First and most important
is the Frequency Adjust control. Rotate the Threshold control as far to
the right as it will go. Then turn the Discriminate control to far left.
Now listen to the detector. The Discriminate control is now actually a Frequency
Adjust control. It has 32 separate positions. Unfortunately, the 32 positions
are not marked! So turn the knob a tiny amount to the right and wait a couple
seconds. The machine interference may be reduced, may increase, or may stay
the same. Then advance again a tiny amount, and listen a couple seconds.
The idea is to slowly advance through the different settings looking for
Once you find the quietest setting, turn the Threshold control back to
about “4”. This will lock in the Frequency setting, and it will remain set
until you adjust it to something else. Be sure and rotate the Discrimination
control back to “0” and you are set to detect.
One thing that helps a lot is to keep the coil flat on the ground. In
town the coil is like an antenna, and lifting it at an angle off the ground
can massively increase the interference. So making the above adjustment
with the coil flat on the ground will usually be the way to go.
In populated areas, you will still be likely to receive faint noises
and spurious false signals. Like most false signals, the key is repeatability.
Real signals repeat over a certain spot, false signals come out of nowhere
and then are gone. I tend to run my VLF detectors on the ragged edge of
performance, with the gain set high. In doing so I get lots of false blips
and tiny signals. So I've long since learned to ignore this kind of noise.
But for beginners it can be difficult to deal with. Remember - repeatable
signals are the real ones.
DD coils are less prone to interference than mono coils, and smaller
coils are less prone than larger coils. So a change of coils may help. Finally,
as most of these false signals are fainter than most genuine targets, reducing
the threshold slightly lower than normal can eliminate most of them while
still getting all but the faintest real signals.
I have been able to operate in town near power lines with quite a bit
of background noise. I set my headphones very quiet and listen more to the
tone of the signals than the volume. Genuine signals simply sound different
than the noise produced by the electrical interference. But if the noise
gets bad enough, it can be a real obstacle to pleasant detecting and some
areas will simply be off-limits to the Infinium. But please do not take
this explanation to mean this is a major issue. It is something all PI detectors
face to varying degrees in areas where there are many electrical sources.
In unpopulated areas the Infinium is very quiet with a very smooth threshold,
except rare blips that may come from distant lightning.
DETECTOR PROSPECTOR FORUM FOR EXPERT ADVICE!
As far as the Power/Tracking settings go, I’ve been able to discern little
difference between the settings. I generally just set my Infinium on “Slow”
and forget about it. In theory, you may be able to hit slightly smaller
or deeper targets by switching to “Fixed” after the machine tracks into
the ground for a couple minutes, but I have noted no real improvement myself.
The “Fast” setting is supposed to help with the worst ground conditions,
but again, I have not seen a situation where I felt it made a difference.
So “Slow” it is for me.
My view of the Discriminate control does not agree at all with what it
is billed as. I’ve played with it a lot, and as far as I am concerned it
acts just like a sensitivity or gain control. At “0” you have max sensitivity
to small items, and max depth. As you advance the control, you lose overall
sensitivity. Low conductive targets are affected the most. So the "Reverse
Discrimination" theory is that if you advance the control all the way
and still get a signal, it is junk. If it disappears, you are supposed to
Well, it does not work that I can see. All that happens in reality is
the weakest signals are eliminated and strong signals remain. Big junk at
the edge of detection depth has a weak signal, and so this “Reverse Discrimination”
method calls it good since the Discrimination control causes it to disappear.
Conversely, a 2 ounce gold nugget an inch down responds no matter what.
So it should not be dug?
Nope, forget all that. The discrimination control can be thought of as
a sensitivity control, just like that on a VLF detector. Reducing the sensitivity
by advancing the control above “0” can reduce ground noise, particularly
in salt water environments. If you are getting lots of ground signals or
hot rocks that will not track out, try advancing the Discriminate control
to eliminate them. If you are having a problem with tiny trash items, advancing
the Discriminate control can eliminate some of them. But the more you advance
the control, the less overall depth you will get on most targets. But just
like lowering sensitivity or gain on a VLF detector can result in smoother
operation and actually better performance, so advancing the Discriminate
control on the Infinium to reduce unwanted signals can result in better
Finally, the best is last. The dual tone discrimination on the Infinium
really does work, and work well. The catch is it might not work like you
think it should!
A hi-lo tone means aluminum, gold, nickels, zinc pennies, and various
wire-like items. Like small, thin nails, bobby pins, and actual wire. Some
thin, flat, flaky rusted steel reads hi-lo. If nugget detecting or beach
detecting, hi-lo tones are the ones to go after to get the gold nuggets
and gold jewelry.
Silver, copper, and clad coins read lo-hi. As does larger steel junk
or relics. Want old silver deeper than any VLF detector will detect? Dig
lo-hi tones. You will come up with larger, heavily rusted items of all sorts
but you will be amazed by the depth you pull up coins with an Infinium.
The worse the ground mineralization, the more advantage the Infinium will
have over VLF detectors. Try digging lo-hi tones only, and you will find
deep coins others are missing. See
Coin Detecting with the Garrett Infinium for details.
You can use the
discriminate control in conjunction with the dual tones to get a bit
more information about the target. I have found
in actual practice, however, that I rely strictly on the tones for making
my digging decisions. Gold - always dig hi-lo tones. Silver coins - always
dig lo-hi tones.
In very trashy locations it pays again
to keep headphone volume low so as not to be overwhelmed by the signals.
I have a favorite freshwater beach I hunt. It is hunted to death, and VLF
detectors can barely find any targets. My Infinium made the beach seem like
it had never been detected. There are signals everywhere. Sure, I’m digging
iron junk, and lots of aluminum. But I’m pulling up old coins passed over
by thousands of detectors. The biggest catch is you need a location where
digging large deep holes is ok… and backfill them! A good pinpointer like
the DetectorPro Uniprobe
is a major help also.
You will also find that on shallow or very large targets the audio will "stick"
or drag on for a longer than normal time. In other words, a deep coin will
give a nice little tone similar to what a VLF might. But the same coin an
inch below the surface will exhibit this "dragging tone" effect.
Bury a quarter at 8" and one at 1" and note the difference. This
effect can be used to determine the size and depth of targets. Be careful
in trashy areas, as closely spaced targets can be "masked" by
the effect. A dragging tone from a shallow junk item can cause an adjacent
deep good item to be missed. Moving very slow in trashy sites helps considerably.
Nugget detecting with the Infinium
is pretty much a no-brainer. Most mining areas will have no interference
issues, except perhaps other detectors. I prefer to hip mount the Infinium
for long hours of detecting. I keep it on the rear of my hip so that I do
not stress the coil wire when bending over. Make sure and get a coil cover
for nugget detecting as rocks and gravel are rough on coils. The stock 14" x 10"
DD coil is probably best for most nugget detecting applications, but it
is nose-heavy when the control box is hip mounted. If ground conditions
allow the 14"x10" mono is lighter and will get slightly better
depth in mild ground. I like the 10" x 5" DD for hip mounting applications,
as the wand/coil combo is very light and works well is steep terrain or
thick brush. If you do get into heavy iron junk, oversize iron reads lo-hi,
while nearly all gold nuggets read hi-lo. But when possible dig it all!
Tidbits... The 14" x 10" mono
coil is much easier to pinpoint with than the DD version and gets a bit
more depth dead center. But it is nosier in areas with electrical interference
and if used nugget detecting will hit hot rocks more than the DD coil. Still,
it is my favorite coil. The 8" round mono coil is very popular with lots
of people. Mono coils are more sensitive around the edges than
in the center, so tiny surface targets will signal at each edge, giving
a double blip. It also makes pinpointing these tiny items hard - try dragging
one edge along the ground. The little 7" x 3" DD is the most sensitive
to small items and is fantastic for working trashy sites, but like most
small coils does not cover ground well and gives up overall depth. I prefer
it for wading at I can pinpoint and scoop so well with it, and it is great
for nugget detecting deep nooks and crannies. To pinpoint excavated items
in a pile of dirt with the elliptical coils, try dragging the coil pointed
end down in the dirt. The target will signal directly off the nose of the
coil. For those so inclined, I cut my Garrett headphones off a few inches
above the waterproof connector. I wired a 1/4" female receptacle onto
the end creating a "dongle" into which I can plug any headphones.
You can put a 1/4" male jack onto the Garrett phones so as not to waste
them. One thing to look out for are large elongated steel items. Like a
steel strap a foot long or a long spike. These can signal well off one end
or the other. Again, a powerful pinpointer can help with un-centered targets.
I hope these notes help. The main thing to remember is that this is a
radically different detector than any VLF machine. In some ways it is like
the early, cruder VLF detectors. Weird operating methods, poor discrimination…
but genuine raw power is the reward. Be patient and dig it all for awhile,
and I promise you will make finds with the Infinium that would not be possible
with a VLF detector. Parting word - keep the coil low, and swing it slow!
PI detectors do not like air space between the coil and ground, and are
slower to respond than VLF detectors.