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