28 TDI
Pr o
Owner ’s Gui de
The Variable Audio feature can be further interpreted by the tone which it
produces when sweeping over a target. As the search coil passes over a
detected target, the signal will get louder as it gets closer to the center of
the search coil. After the center of the search coil the tone will rise or fall
depending on the decay speed.
Therefore, on a low-conductive target (small to medium gold, nickel coins,
and small iron) the pitch of the audio tone might rise after passing the
center of the search coil.
When the search coil goes over a high-conductive target (large gold, most
silver and copper coins and most large iron) the pitch of the audio tone
might fall after passing the center of the search coil.
The low tone heard over large non-iron targets (large gold, silver, copper)
is usually smoother than the low tone heard over iron targets which can
be irregular. In addition, fl at iron or steel objects, such as tin lids and fl at
sided cans can give a mixed response. Mixed responses sound like low
tone, high tone, low tone as coil passes over the target. The sweep will
have to be slower to notice this mixed response. The high-tone response
is usually stronger and longer, but with time and practice this can be help-
ful to identify fl at iron.
With practice, you will be better able to use your low tone and high tone to
help you get an idea of what kind of target you are detecting and help to
eliminate some trash items. However, it is always better in a new area to
dig everything until you get an idea of what you are likely to fi nd. Keep in
mind that no system is perfect, and when in doubt DIG!
