Lot's of helpful info , Guess ill try You-Tube.
Thanks V-Magnum P.I. Car -Guy.
OK, then, here's some tips for the GPX relic hunter (I don't use GPX for prospecting and use it only in hot soil, so that is the basis for my "tips"):
The Key to GPX is understanding what the settings do and getting it to run STABLE. This is highly dependent on what is going on around you and the site conditions, so I avoid use others recommended "settings" because they mean nothing if you do not know what the settings do to machine performance.
This is how I approach my GPX setup for a hot soil relic hunt.
1. Set up your front panel toggle switches correctly (these are based on the 4800):
Search Mode - General (doesn't really matter these positions are just three slots where you can customize settings to your liking the only difference being in the default settings for some parameters)
Soil Timings - Start out in Normal the more complex timings in Special and Enhance mode can be tried later.
Coil/Rx - This just sets the which coil on a Double D coil is used as the receive coil. It has no effect if you are using a mono loop. I use Double D because the target will pinpoint at the center of the coil, the other settings will cause the target to pinpoint off center.
Ground Balance - Tracking is too slow and can cause targets to disappear when trying to pinpoint them. Use fixed and periodically re-balance using the trigger button on the handle.
2. LCD user user settings:
Set Rx Gain at 8 and Motion on Medium for the following adjustments (if you use slow motion then you are locked into slowing the coil swing down, medium allows you to use a normal search swing and you can always slow your swing down to zero in on a target as necessary). I use NRM audio (not deep or boost) and all the other default audio, signal and target volume settings.
3. Find a quiet channel. You can use AutoTune to do this (takes awhile) or dial it manually to a quiet channel. I like to use numbers well away from the default channel when hunting at sites with a lot of other GPX users. Typically a channel number less than 100.
4. Adjust the threshold just high enough to know the machine is alive. Too high and you will miss the squeaker targets and too low you may not hear some faint targets. Again keep the machine running just on the edge of being completely quiet.
5. Do a quick ground balance.
6. Raise your coil in the air at this point and make sure it is on the edge of quiet and adjust threshold as necessary.
7. Put your coil on the ground again and swing, GB as necessary by pumping while pressing on the trigger button. If noise doesn't decrease, something like Rx Gain, Threshold, or Receive Channel may still be off. Adjust as necessary.
8. Leave stabilizer at the default. You can adjust it higher until you hear a change in the threshold and then back off one notch, but I just usually leave it alone.
9. Setting Iron Reject - Too high and you will get blanking on good targets like minie balls so I recommend keep it at 7 max or less. Iron reject won't work on a mono coil.
After you have your machine set up, then recognizing target audio is the key and that comes from getting out there swinging and digging.
There are always exceptions to truisms like minie balls giving a nice smooth low tone with no blanking or buttons giving a nice sharp high tone. Or nails giving you a high tone warble if you swing along the length of a nail vs. swinging across the shank, etc. The best I can tell you is some good targets may sound like nails, some large iron makes good relics (bayonets and swords) and if you get a consistent signal from two 90 degree swings then dig it.
HTH
