A
Anonymous
Guest
Air testing or using a test garden shows one has two extreme ways of setting up the sensitivity and threshold in the field when site conditions are very bad:
Extreme Setup #1) Using a very high sensitivity setting and dialing in very high negative threshold setting to stabilize the audio and allow one to search in mostly silence.
Advantage-This generates a "wide electromagnetic field " and only those targets that do not fall in the notched out areas at a reasonable depth with a decent signal will be detected. Large targets can be detected deeper and small iron, steel, tin, foil will be ignored by the high negative threshold. Very little overlapping is needed for effective coverage since the transmitted field is very wide at high sensitivity settings. The maximum effective depth attainable with this setting will be best in areas with widely scattered surface trash
Drawback- the "wide field of detection" near the surface generated by the high sensitivity setting can degrade target unmasking by the CS and generate high tone falses caused by shallow steel or rusty tin objects. The maximum effective depth attainable with this setting will degrade as the shallow surface trash increases thus blocking the detection of deeper items.
Extreme Setup #2) Using a lower sensitivity setting and very little if any negative threshold to stabilize the audio.
Advantages- Allows better target separation due to the "smaller electromagnetic field of detection", superior unmasking due to not overloading the receiver, allows the DSP to sniff out small amounts of Nonferrous metals, decreases "high tone falses" due to shallow steel shorting the transmitted signal directly into the receive windings when between the two windings and very close. Allows more effective depth as the narrow field can shoot down between shallow targets and detect even deeper targets that would be missed by using higher sensitivity settings. Good targets sound better when using less negative threshold. Smaller targets that generate a weak signal can be detected easier and less likely eliminated by the excessive use of the negative threshold.
Drawback- The width of the field of detection is greatly reduced requiring one to overlap the coil swings by 50-75% to ensure complete coverage without any gaps. Extremely deep targets will be missed as the field of detection is shallow. Will allow detection of small bits of steel, rusty tin, abrupt changes in mineralization or any other small but highly conductive trash because the negative threshold is set very low.
Summary- There is no one perfect setup for a typical site as the amount of mineralization and iron and nonferrous trash are rarely uniform over the entire site. Using 2 or more setups, extreme or otherwise, from 2 or more different directions as you grid off the site and run a tight overlapping pattern, will flush out more goodies missed by previous setups or other detectorist who were there previously.
Extreme Setup #1) Using a very high sensitivity setting and dialing in very high negative threshold setting to stabilize the audio and allow one to search in mostly silence.
Advantage-This generates a "wide electromagnetic field " and only those targets that do not fall in the notched out areas at a reasonable depth with a decent signal will be detected. Large targets can be detected deeper and small iron, steel, tin, foil will be ignored by the high negative threshold. Very little overlapping is needed for effective coverage since the transmitted field is very wide at high sensitivity settings. The maximum effective depth attainable with this setting will be best in areas with widely scattered surface trash
Drawback- the "wide field of detection" near the surface generated by the high sensitivity setting can degrade target unmasking by the CS and generate high tone falses caused by shallow steel or rusty tin objects. The maximum effective depth attainable with this setting will degrade as the shallow surface trash increases thus blocking the detection of deeper items.
Extreme Setup #2) Using a lower sensitivity setting and very little if any negative threshold to stabilize the audio.
Advantages- Allows better target separation due to the "smaller electromagnetic field of detection", superior unmasking due to not overloading the receiver, allows the DSP to sniff out small amounts of Nonferrous metals, decreases "high tone falses" due to shallow steel shorting the transmitted signal directly into the receive windings when between the two windings and very close. Allows more effective depth as the narrow field can shoot down between shallow targets and detect even deeper targets that would be missed by using higher sensitivity settings. Good targets sound better when using less negative threshold. Smaller targets that generate a weak signal can be detected easier and less likely eliminated by the excessive use of the negative threshold.
Drawback- The width of the field of detection is greatly reduced requiring one to overlap the coil swings by 50-75% to ensure complete coverage without any gaps. Extremely deep targets will be missed as the field of detection is shallow. Will allow detection of small bits of steel, rusty tin, abrupt changes in mineralization or any other small but highly conductive trash because the negative threshold is set very low.
Summary- There is no one perfect setup for a typical site as the amount of mineralization and iron and nonferrous trash are rarely uniform over the entire site. Using 2 or more setups, extreme or otherwise, from 2 or more different directions as you grid off the site and run a tight overlapping pattern, will flush out more goodies missed by previous setups or other detectorist who were there previously.