The Garrett ADS Groundhog is a vintage metal detector that is still in use by hobbyists who use it to locate buried historical treasure such as old coins or metallic artifacts. Building and plumbing professionals also use it to locate underground gas pipes and electric or communications cables that must be dealt with before building or repair can commence on a new site. This metal detector can either be tuned manually or automatically. You need to tune it manually the first time even if you intend to use it in automatic tuning mode.
Turn the power knob of the Garrett Groundhog, which is located at the top right of the four-knob control panel, fully clockwise to the "On" position.
Flip the tuning selector switch in the middle of the control panel to your choice of "Manual" or "Automatic." Press the "Master control switch" at the end of the handgrip if you have chosen the manual tuning mode.
Rotate the tuning knob, which is located to the left of the power knob, away from the "Null" or quiet zone until you hear a faint buzzing sound. This is the optimum tuning setting for the Garrett Groundhog.
Press the "Master control switch" to the left for one second if you are operating your detector in the "VLF Ground Cancel" mode or to the right for one second in the "TR Discriminating Mode" to keep your detector tuned when you have set it for manual tuning. It will tune automatically if you have chosen automatic tuning.
Reset the optimum tuning point at any time while you are using your detector by repeating Steps One through Four.