Minelab The Sovereign Manuel du propriétaire télécharger pdf (Page 30)

Techniques and Methods

You can obtain an additional 1 to 3 inches more depth by turning the sensitivity

control to just off the auto position while detecting over lightly mineralized soil or

sand. This might cause the detector to become unstable and produce false signals.

The detector will also have a tendency to ID more nails and elongated iron as good

targets. If this occurs try following the steps outlined in the Advanced Tuning

section.

You can make a fairly accurate judgment on how deep a coin size target is by first

bench testing a dime or a penny to find the distance from the coil they produce a

good but faint signal. Say for example your air test produces a faint signal at eight

inches. At a park you find a probable penny target and when you raise your coil 3

inches you receive and hear that faint air test signal. Your target is probably 5 inches

deep if it's a penny sized object. However, if you had to raise the coil 10 inches

above the ground to hear that same air test signal, you will find that the target isn't a

penny but an object much larger in size.

If you are using the default multi-tone option then this next technique might be

helpful. All targets cause the pitch of the threshold to change to the pitch of the target

encountered. For example if you pass a nickel across the coil the threshold hum will

change it's pitch to that of the nickel. Keep the threshold audio hum low but still loud

enough to hear all pitch changes. On rejected targets the threshold will go silent.

When you are in a concentration of junk the silent threshold is a sign for you to slow

down that searchcoil sweep speed or switch to a smaller coil. A real deep coin target

may not have enough volume to produce a positive signal but the threshold pitch will

change to that of the coin target until the next target changes it again. These kinds of

changes should be investigated further as they can indicate a good target that’s very

deep. Be aware that not hearing a threshold hum may cause you to miss targets. So

when that threshold goes silent remember to really slow down to a crawl to get the

threshold back. One fellow says he has slowed down to 6 seconds per sweep and

found Indian heads etc. that were simply missed because of the masking of the iron

trash.

Searchcoil covers can and do accumulate dirt and water if they aren't sealed in some

fashion. You can keep the dirt and moisture out by wrapping electrical tape around

the coil and cover at the joint. This will also make removing the cover in the future

an easier task.

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Minelab The Sovereign Manuel du propriétaire Page 30