This GB adjustment is not difficult to understand but I do need to clarify that from the onset, I recommended any SPP owner to add the high/low conductivity switch. With that switch life becomes easier to understand because signals can be separated.
Now, with that said, when you adjust the GB, you can change most of the ground signals or basalt from a high tone to a low tone easily. Usually, it takes just a slight adjustment from perfect GB. Also, any "hot spots" that sound off as a high tone can also easily be changed to a low tone with a slight GB adjustment. Again, basalt can also be changed from a high tone to a low tone easily and usually it takes just a little GB adjustment. At the same time, all small gold will remain a high tone throughout the GB adjustment. So, changing the problem signals from a high tone to a low tone and switching to high tone only, the only the gold or other small non gold objects will be detected.
So, if you switch to a low conductor mode (high tone only), and you adjust basalt and/or hot spots to a low tone, then you will be able to easily hear small gold signals but not hear any hot spots or basalt signals if the GB is adjusted properly. The result is, gold signals will come through clear but basalt and hot spots are ignored. This is what is displayed in lukeozdigger's video(s) and in one of those videos, he says, he could do this all day long, referring to how smooth the threshold is and lack of signals from the ground hot spots.
This makes hunting in areas where the ground changes quickly or basalt is very common extremely easy to do because basalt and hot spot ground signals will simply be ignored while you can still detect small gold or other gold that responds as a high tone which can often include large specimen or less pure gold. Now, some depth may be lost but that is a small price to pay if it makes detecting such areas much easier to do.
Next, the question was asked of the autotune feature would help keep the threshold steady under these conditions. The answer is yes, providing a person tries to keep the coil level and sweeps smoothly. Poor sweep techniques can further reduce depth of detection of gold signals.
Again, this GB offset allows a person to hunt in basalt infested areas and not chase non gold signals caused by the basalt or hot spot ground signals and still detect the gold signals.
The question was also asked why in the world operate this way? Well, if you test thoroughly, you will find advancing the delay will cause more small gold to be ignored and it would require operating with a later delay all the time in basalt infested areas. The selection of low conductor mode allows one to ignore any ground signal or basalt signal that is converted to a low tone by simply advancing the GB just enough to do the job. This technique keeps the threshold much smoother overall.
Either the GB or the delay method will work and can be easily used once a person understands what is needed to be done. So, either method could be used on the SPP, SL, or TDI in areas that can cause big problems for other PI's that don't have a feature to allow one to ignore basalt or lots of hot spots. I do recommend people try both methods until they understand what is going on. This simple feature adds versatility to the White's PI's not available on most other brands.
Keep in mind that either method mentioned should only be used in problematic areas. Ideally, perfect GB is recommended. However, in certain areas, that may not be the best solution and the delay or GB offset technique may be a better choice.
One final note, this GB shift is used here in the US when hunting silver and copper coins, but uses the high conductor mode and reduces the GB sufficiently to cause iron objects to transition to a high tone. Then shutting off the high tones minimizes iron junk from being detected, while providing good signals from old high conductor coins.
Reg
Now, with that said, when you adjust the GB, you can change most of the ground signals or basalt from a high tone to a low tone easily. Usually, it takes just a slight adjustment from perfect GB. Also, any "hot spots" that sound off as a high tone can also easily be changed to a low tone with a slight GB adjustment. Again, basalt can also be changed from a high tone to a low tone easily and usually it takes just a little GB adjustment. At the same time, all small gold will remain a high tone throughout the GB adjustment. So, changing the problem signals from a high tone to a low tone and switching to high tone only, the only the gold or other small non gold objects will be detected.
So, if you switch to a low conductor mode (high tone only), and you adjust basalt and/or hot spots to a low tone, then you will be able to easily hear small gold signals but not hear any hot spots or basalt signals if the GB is adjusted properly. The result is, gold signals will come through clear but basalt and hot spots are ignored. This is what is displayed in lukeozdigger's video(s) and in one of those videos, he says, he could do this all day long, referring to how smooth the threshold is and lack of signals from the ground hot spots.
This makes hunting in areas where the ground changes quickly or basalt is very common extremely easy to do because basalt and hot spot ground signals will simply be ignored while you can still detect small gold or other gold that responds as a high tone which can often include large specimen or less pure gold. Now, some depth may be lost but that is a small price to pay if it makes detecting such areas much easier to do.
Next, the question was asked of the autotune feature would help keep the threshold steady under these conditions. The answer is yes, providing a person tries to keep the coil level and sweeps smoothly. Poor sweep techniques can further reduce depth of detection of gold signals.
Again, this GB offset allows a person to hunt in basalt infested areas and not chase non gold signals caused by the basalt or hot spot ground signals and still detect the gold signals.
The question was also asked why in the world operate this way? Well, if you test thoroughly, you will find advancing the delay will cause more small gold to be ignored and it would require operating with a later delay all the time in basalt infested areas. The selection of low conductor mode allows one to ignore any ground signal or basalt signal that is converted to a low tone by simply advancing the GB just enough to do the job. This technique keeps the threshold much smoother overall.
Either the GB or the delay method will work and can be easily used once a person understands what is needed to be done. So, either method could be used on the SPP, SL, or TDI in areas that can cause big problems for other PI's that don't have a feature to allow one to ignore basalt or lots of hot spots. I do recommend people try both methods until they understand what is going on. This simple feature adds versatility to the White's PI's not available on most other brands.
Keep in mind that either method mentioned should only be used in problematic areas. Ideally, perfect GB is recommended. However, in certain areas, that may not be the best solution and the delay or GB offset technique may be a better choice.
One final note, this GB shift is used here in the US when hunting silver and copper coins, but uses the high conductor mode and reduces the GB sufficiently to cause iron objects to transition to a high tone. Then shutting off the high tones minimizes iron junk from being detected, while providing good signals from old high conductor coins.
Reg
