1. Concentric coils use two round antennas, one inside the other. This search coil is used on metal detectors designed for coin, jewelry, and relic hunting. Concentric coils discriminate and pinpoint well because the strongest signal is always in the center of the coil.
2. Widescan coils (also called double-D) coils use two D-shaped
antennas placed back to back. This search coil is less affected by
mineralization than the concentric coil, so it is generally used for
gold prospecting or relic hunting in mineral-rich ground.
3. Larger search coils go deeper than smaller coils, but only on
larger targets. When using a large coil, you may lose sensitivity to
small targets.
4. Smaller coils will concentrate the signal and make the detector
more sensitive to small targets. As a trade-off, smaller coils tend to
lose depth compared to larger coils.
5. Using a search coil cover when storing your metal detector will help keep your coil in top condition.
6. Metal detector bags are a wise purchase that will work to protect your investment from moisture and dust.
7. You will pay more for rechargeable batteries up front. However, consider that you need to replace them far less often than regular batteries.
8. If your metal detector uses 8 AA batteries, regular alkalines
will produce 12 volts, while rechargeables will produce roughly 9.6
volts. This slight difference will not affect the sensitivity and depth
potential of your detector, though it will affect the time that you are
able to hunt.
9. Serious treasure hunters may want to invest in prospecting tools such as trowels, scoops, pans, and other useful field tools.