I learned a valuable lesson in my younger days....an old guy with a beatup compass whooped my hiney in a contest at an old abandoned house lot in Tampa, which was totally trashed. This guy, he knew his detector so well, he could hear nonferrous targets within the ferrous and his was no discriminator!
So any detector you take the time to practice with, and learn, will find you good stuff. The coinmasters are especially good to get to know because they are super powerful, super adjustable, and last a long time.
If its out of warranty and you want to experiment, you can try adding 2 more batteries to the pack, it WILL give you increased depth and power. This may cause any weak pints on the circuit board to fry though, fyi...so far I have not had that happen. I have converted c packs to D, and added 4 additional AA bateries to an old coimaster 6db whose pack already took 14 AA batteries!
!!
No kidding, but that addition of 4 more AA made a real big difference.
I also use an easy and cheap amplifier of my own design which works especially well for sound outputs on the coinmasters (Most ALL detectors actually), the plans are still for sale at
www.autodidactics.com (
http://www.autodidactics.com/energy.htm) and will give the user a BIG advantage. There is other good free info at that site too. People I know who use the super booster, as well as yours truly, have gone back over so-called hunted out areas, and with the extra inch or two of depth its amazing what one can find in these places. Amazing.
Good luck,