Copy from FAQ: Posted by Digger
Definitions:
Water resistant: May be splashed, washed, used in drizzling rain, or moved through wet grass. Must not be submersed under water.
Water proof: Submersible to 1 meter. Ideal for shallow water wading and gold prospecting in shallow streams.
6 Concentric
7.5 kHz Coil
All X-TERRA series detectors
Water proof
If there are coins and relics hiding amongst iron junk, this coil is the one that will find them. The best X-TERRA coil for target separation.
6 Double-D
18.75 kHz Coil
X-TERRA 50, 70, 305, 505 and 705 detectors
Water proof
The most sensitive X-TERRA coil available, it is great for sub-gram nuggets, specimens, and gold jewellery. Also ideal for shallow streams.
9 Concentric
7.5 kHz Coil
All X-TERRA series detectors
Water proof
The standard X-TERRA coil for good reason good depth, great target separation and accurate pin-pointing the perfect coin hunting coil.
9 Concentric
18.75 kHz Coil
X-TERRA 50, 70, 305, 505 and 705 detectors
Water proof
Has same properties as the 7.5kHz version, but more sensitive to low conductive targets. Also performs well when detecting for jewellery on ocean beaches.
9 Concentric
3 kHz Coil
X-TERRA 70, 505 and 705 detectors
Water proof
Ideal for highly conductive targets such as silver, copper, large rings and relics. Performs well in all soils with the exception of highly mineralised soil.
10 x 5 Double-D
18.75 kHz Coil
X-TERRA 50, 70, 305, 505 and 705 detectors
Water resistant
This coil has great sensitivity, good ground coverage, and is easy to use in rough terrain. An ideal gold hunting coil, that also performs well for beach work.
10 Round Double-D
7.5 kHz Coil
All X-TERRA series detectors
Water resistant
For improved depth and ground coverage over the standard 9 Concentric, this is the coil to use. It also performs well in mineralised soils.
10 Round Double-D
18.75 kHz Coil
X-TERRA 50, 70, 305, 505 and 705 detectors
Water resistant
An ideal coil for beach work, and open areas, this coil offers good depth and sensitivity, and great stability in mineralised soils and beaches.
Information provided by:
Justin Adams
VP, North America and General Manager, Global Marketing
Minelab Electronics
