Metal Detecting - Understanding the Technology Is Important

Metal Detecting for fun or profit can be one of thethis technology have two search coils. One coil called
most exciting and rewarding of hobbies. A metalthe 'transmitter coil' transmits electricity rapidly many
detector can cost very little, as low as $50 or highertimes per second, first in one direction around the
that $400 for a top of the line model. This is onecoil, then in the other direction. The other coil called
hobby where you really do get what you pay for,the 'Receiver Coil' acts just like the name implies it
because the more expensive top of the linereceives frequencies or data that come or 'bounce'
detectors use the most advanced technology andback from the objects the transmitter coil detects in
they have the best features available.the search area. This type of Metal Detector is great
Metal Detectors use one of three types offor it's ability for being able to distinguish between
technology:different types of metals.
BFO (Beat Frequency Oscillation) - Metal DetectorsThe first metal detector my wife and I bought
using BFO technology have two coils of wire, onetogether cost about $69.00 it was one of them
large coil is located in the search coil of the detector,cheap ones that used the 'BFO' technology. This was
the other small coil of wire is located within theone of them metal detectors you see in the
System Control Pack. Each coil of wire is connectedmagazines that sell other household items, etc. You
to an oscillator that produces pulses of current.can buy cheap metal detectors like these at most
These pulses of current pass through the coilsRadio Shack stores, and some K Marts and Wal
generating radio waves. A receiver housed within theMarts. The first day we took the metal detector
System Control Pack receives the radio waves andoutside we started finding some neet things and my
makes a series of tones based upon the frequencieswife and I were hooked. We did find our share of
of the radio waves. When the detector search coiljunk items in the yard, like aluminum foil, nails and the
passes over a coin or other metal item a magneticusual pull tabs and junk metal. But we also found 7
field is created around the coin or metal item, thisold diecast cars in great condition. They were all
magnetic field causes interference with thedifferent and were 'TOOTSIE' diecast vehicles. I
frequency of the radio waves generated by thelooked on eBay and the bunch was worth around $15
search coil. And changes the tone produced by theor more. We also found a 1961 silver Roosevelt dime
reciever.in fine condition, in our yard, plus the usual pennies.
Metal Detectors using BFO technology are the onesAfter reading about how the 3 different types of
your likely to get when paying under $100 for, that'sMetal Detector technologies work and differ from
right, the cheapies. The BFO technology is the easiesteach other, you must decide how or what you will
and cheapest to make, thus the prices of thebe mostly using your metal detector for. Will you be
detectors are cheap. The only problem is, BFOhunting for small objects like coins, jewelry and gold
technology is very limited when compared to PI andnuggets, or searching for a large cache or object.
BFO detectors, and the ability to distinguish betweenThe things you may want to use your detector for,
junk metals and silver or other coins is very poor.play one of the most important factors besides
PI (Pulse Induction) - Metal Detectors using PIpricing in deciding what type of detector to buy.
technology sometimes use a single coil or a series ofMost folks want a detector that is great at finding
coils working together as a transmitter and receiver.coins, gold nuggets, and jewelry on the land and in
Short bursts of electrical current are send through asmall creeks and streams, this would be a detector
coil of wire, causing a magnetic field. When the burstusing 'VLF' technology. Almost all of the modern
of electrical current ends the magnetic field reversesdetectors have a waterproof search coil which make
polarity. A sharp electrical spike is created, then moresearching in shallow creeks and streams possible.
pulses are created, the whole process repeats andThere is Computer Software that is made just for
works like a series of echoes, giving a differentthe hobby of Metal Detecting. The software is called:
report or echo depending upon the metal itMetal Detector - Treasure Hunter Professional, and
encounters. This type of metal detector is not verymay be seen at this website address:
good for discrimination between different types ofBy Robert W. Benjamin
metals or coins, but it is good to use where someCopyright © 2005
other types of metal detectors have troubleYou may publish this article in your ezine, newsletter
working, such as in salt-water, and metals can beon your web site as long as it is reprinted in its
detected much deeper with this technology than theentirety and without modification except for
others.formatting needs or grammar corrections.
VLF (Very Low Frequency) - Metal Detectors using