DD?

DD = Double D

Basically the coil has two D shaped wire thinga ma giggs. Do a search online :P

The old term was 2D which had 2 coil windings shaped in the form of the letter D facing back to back and crossing over each other at the front and heal of the coil. The newer DOUBLE D coils are much the same but the 2 coil windings never cross. This way the signal is compressed into the middle of the coil and straight down. They are geat for high mineral content ground and great depth. The drawback is they are hard to pinpoint with and you need a good eal of practice to do it.

i have a DD with my minelab an can pinpoint on a dime with ease, just you the x method.. I can pop a coin out of the ground with a poke of a screwdriver, most times with 1 hit, unless it is more than 3" down, but can still get almost any coin out with a hole no bigger than 3"-4" across