| Metal Detecting for fun or profit can be one of the | | | | this technology have two search coils. One coil called |
| most exciting and rewarding of hobbies. A metal | | | | the 'transmitter coil' transmits electricity rapidly many |
| detector can cost very little, as low as $50 or higher | | | | times per second, first in one direction around the |
| that $400 for a top of the line model. This is one | | | | coil, 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 line | | | | receives frequencies or data that come or 'bounce' |
| detectors use the most advanced technology and | | | | back 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 of | | | | for it's ability for being able to distinguish between |
| technology: | | | | different types of metals. |
| BFO (Beat Frequency Oscillation) - Metal Detectors | | | | The first metal detector my wife and I bought |
| using BFO technology have two coils of wire, one | | | | together 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 the | | | | one of them metal detectors you see in the |
| System Control Pack. Each coil of wire is connected | | | | magazines 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 coils | | | | Radio Shack stores, and some K Marts and Wal |
| generating radio waves. A receiver housed within the | | | | Marts. The first day we took the metal detector |
| System Control Pack receives the radio waves and | | | | outside we started finding some neet things and my |
| makes a series of tones based upon the frequencies | | | | wife and I were hooked. We did find our share of |
| of the radio waves. When the detector search coil | | | | junk items in the yard, like aluminum foil, nails and the |
| passes over a coin or other metal item a magnetic | | | | usual pull tabs and junk metal. But we also found 7 |
| field is created around the coin or metal item, this | | | | old diecast cars in great condition. They were all |
| magnetic field causes interference with the | | | | different and were 'TOOTSIE' diecast vehicles. I |
| frequency of the radio waves generated by the | | | | looked on eBay and the bunch was worth around $15 |
| search coil. And changes the tone produced by the | | | | or 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 ones | | | | After reading about how the 3 different types of |
| your likely to get when paying under $100 for, that's | | | | Metal Detector technologies work and differ from |
| right, the cheapies. The BFO technology is the easiest | | | | each other, you must decide how or what you will |
| and cheapest to make, thus the prices of the | | | | be mostly using your metal detector for. Will you be |
| detectors are cheap. The only problem is, BFO | | | | hunting for small objects like coins, jewelry and gold |
| technology is very limited when compared to PI and | | | | nuggets, or searching for a large cache or object. |
| BFO detectors, and the ability to distinguish between | | | | The 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 PI | | | | pricing in deciding what type of detector to buy. |
| technology sometimes use a single coil or a series of | | | | Most 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 a | | | | small creeks and streams, this would be a detector |
| coil of wire, causing a magnetic field. When the burst | | | | using 'VLF' technology. Almost all of the modern |
| of electrical current ends the magnetic field reverses | | | | detectors have a waterproof search coil which make |
| polarity. A sharp electrical spike is created, then more | | | | searching in shallow creeks and streams possible. |
| pulses are created, the whole process repeats and | | | | There is Computer Software that is made just for |
| works like a series of echoes, giving a different | | | | the hobby of Metal Detecting. The software is called: |
| report or echo depending upon the metal it | | | | Metal Detector - Treasure Hunter Professional, and |
| encounters. This type of metal detector is not very | | | | may be seen at this website address: |
| good for discrimination between different types of | | | | By Robert W. Benjamin |
| metals or coins, but it is good to use where some | | | | Copyright © 2005 |
| other types of metal detectors have trouble | | | | You may publish this article in your ezine, newsletter |
| working, such as in salt-water, and metals can be | | | | on your web site as long as it is reprinted in its |
| detected much deeper with this technology than the | | | | entirety and without modification except for |
| others. | | | | formatting needs or grammar corrections. |
| VLF (Very Low Frequency) - Metal Detectors using | | | | |