ToddB64
Elite Member
Hi All !
Without addressing the word "null" in all it's various forms (noun, verb, adverb, adjective, etc., etc., I think we know that null basically means of no value, zero, non-existent. OK, so that definition is what we usually strive for when adjusting the GB control to null the Threshold "Hum", or whatever description you use to describe your metal detector's Threshold sound.
In addition, due to the level of mineralization in the ground where we decide to hunt, absolute zero Hum may not be possible. Therefore, we adjust the GB control positive or negative to achieve the lowest Hum levels possible as we raise and lower the coil typically from 6" or 8" above the ground, down to about 1" above, repeating this "bobbing" of the coil and noting whether the increase or decrease in Hum level occurs as we lowed or raised the coil and then making the needed GB control adjustments until the Threshold Hum gets as close to 'Spot-on' as possible. However, some detectorists prefer a slightly positive Ground Balance. They believe a tiny bit positive helps the machine run smoother and will work well in more conditions and soil types. I like a 'Spot-on' ground balance setting.
Having said the above, I'll get to the gist of this post. I have a ferrite ring for testing whether or not the GB Variable Resistor (or Variable Potentiometer Control, also referred to as a "POT" in electronics.) in my Tesoro Bandido II µMax control box circuit is functioning correctly. The test involves attempting to null the Threshold Hum while bobbing the coil over the ferrite ring and adjusting the GB control using the method described in the previous paragraph.
I presume a ferrite ring normally contains a much higher degree of iron dust or iron particle saturation than the average ground, and therefore is a more severe test of the GB pot. If the pot passes this test, we can be certain that it is operating correctly and will meet all the ground mineralization challenges normally encountered, at least in the Ohio parks that I hunt.
As always, I welcome your comments.
Thanks,
ToddB64
Without addressing the word "null" in all it's various forms (noun, verb, adverb, adjective, etc., etc., I think we know that null basically means of no value, zero, non-existent. OK, so that definition is what we usually strive for when adjusting the GB control to null the Threshold "Hum", or whatever description you use to describe your metal detector's Threshold sound.
In addition, due to the level of mineralization in the ground where we decide to hunt, absolute zero Hum may not be possible. Therefore, we adjust the GB control positive or negative to achieve the lowest Hum levels possible as we raise and lower the coil typically from 6" or 8" above the ground, down to about 1" above, repeating this "bobbing" of the coil and noting whether the increase or decrease in Hum level occurs as we lowed or raised the coil and then making the needed GB control adjustments until the Threshold Hum gets as close to 'Spot-on' as possible. However, some detectorists prefer a slightly positive Ground Balance. They believe a tiny bit positive helps the machine run smoother and will work well in more conditions and soil types. I like a 'Spot-on' ground balance setting.
Having said the above, I'll get to the gist of this post. I have a ferrite ring for testing whether or not the GB Variable Resistor (or Variable Potentiometer Control, also referred to as a "POT" in electronics.) in my Tesoro Bandido II µMax control box circuit is functioning correctly. The test involves attempting to null the Threshold Hum while bobbing the coil over the ferrite ring and adjusting the GB control using the method described in the previous paragraph.
I presume a ferrite ring normally contains a much higher degree of iron dust or iron particle saturation than the average ground, and therefore is a more severe test of the GB pot. If the pot passes this test, we can be certain that it is operating correctly and will meet all the ground mineralization challenges normally encountered, at least in the Ohio parks that I hunt.
As always, I welcome your comments.
Thanks,
ToddB64