Advanced Tuning
I would recommend that new users learn the basics of their machine before attempting to use the advanced tuning techniques.

1. Set the Disc and Notch controls to your desired settings.

2. Set the all metal/discriminate switch to all metal. Pinpoint on
the Excalibur.

3. Tom the Volume control all the way clockwise.

4. Set the Threshold control to a slight hum.
Slowly sweep the search coil on the ground, side to side, while keeping the searchcoil as close to the ground as possible.

5. Find a patch of ground with no metal in it that is large enough to sweep your coil without hearing a metal target.

6. Place the coil on the ground and hold the coil still.

7. Switch the all metal/discriminate switch to discriminate. Disc on
the Excalibur.

8. Tom the sensitivity control all the way clockwise.

9. While slowly sweeping the coil over the ground previously checked for no metal, turn the sensitivity control as far counterclockwise as possible, without going into "Auto", until falsing occurs.

While continuing to sweep slowly, turn the sensitivity control back slightly clockwise to eliminate the falsing.
To the best of my knowledge, the above setting is about as close to maximum sensitivity that you can set this machine .
if you don't like the sweeping method, you can also find a metal free spot just the size of the searchcoil. Hold the coil still and turn the sensitivity control just off of Auto. If falsing occurs, turn the control clockwise until the falsing stops. Then turn back slightly counterclockwise for a positive setting.

Please note that when using the advanced tuning option, you are maximizing your sensitivity for depth and some falsing may occur. If you have too much falsing or the falsing is irritating, you can reduce your sensitivity slightly more to eliminate it.