Almost every beginner starts by cranking sensitivity to maximum. The logic is obvious: more sensitivity, more depth. In practice more sensitivity means more triggers from grass, from your spade hitting the ground, and from a power line a couple of kilometres away.
The goal of the first setup isn't depth. It's for the machine to stay quiet when there's nothing under the coil. Everything else is measured from that silence.
Sensitivity
Turn it down until the threshold is even. Yes, you lose some very deep targets — precisely the ones you would not have dug anyway, because you would never have heard them through the phantoms. In exchange you stop digging nothing, which across an outing adds up to considerably more finds.
Worth remembering separately: the setting isn't permanent. After rain, on different ground, or with a different coil fitted, sensitivity needs re-seating.
Ground balance
On mineralised soil and on beaches, a machine without ground balance will scream constantly, and no amount of sensitivity adjustment will fix it.
Balance on clean ground with no target under the coil, and re-check when you move to a different zone. Auto ground balance is convenient but doesn't remove the need to listen: if the threshold is still uneven after auto-GB, it's time to do it by hand.
Discrimination
The great temptation of day one is to notch out half the scale so you stop digging rubbish. Don't: along with the nails you'll notch out non-ferrous targets lying next to iron or standing on edge.
The right order is the reverse — first learn to hear iron, then decide what to mask. Detail in the VDI guide.
Recovery speed
If your machine has it, in trash it matters more than maximum sensitivity: the detector has to let go of one target in time to take the next. On clean ground you can afford a little more depth — but only with a stable threshold.
The test garden: ten minutes that pay back
- Bury a nail, a bottle cap, a copper coin and something silver in familiar soil.
- Sweep each one and memorise the tone, not just the number.
- Write down the VDI and the mode.
- Carry the habit into the field — and don't change three parameters at once, or you won't know which one did it.
Write your settings down
After the test garden, save in the outing note: program, sensitivity, ground balance mode, discrimination, coil. In a month you'll be comparing facts instead of impressions — especially useful when the ground changes or new firmware lands.
Before you start the grid
- Ground balance done on the ground you're standing on.
- Sensitivity stable, not "99".
- Discrimination not floored.
- Headphones comfortable.
- Pinpointer on and tested.
FAQ
Beach and salt — what changes?
Stable ground balance, weather sealing, and patience with quiet non-ferrous signals: gold on a beach sounds modest. A woodland setup with no beach mode is best left at home.
Heavy iron trash?
Recovery speed and your ears matter more than maximum sensitivity. See VDI and tactics.
Mineralisation screaming — broken machine?
Almost never. Usually it's a skipped ground balance or sensitivity set too high — go back to the Ground balance and Sensitivity sections above.
Hunt in storms or at night?
In a thunderstorm, no, and that isn't about finds but about sense. See the safety guide.
Odd finds (bi-metal, stones)?
Cleaning is in special restoration cases. In the field, photos only and no chemistry.
Does one universal mode work everywhere?
Rarely. Salt, trash and clean pasture want different things, and the result of each program change is worth logging — otherwise in a month you'll be guessing again.