BarnacleBill
New member
One of my favorite features of the X70 is the real time updating of the display in GB mode while using auto-tracking. I find that this provides me with good information about the characteristics of the ground I am working in as I walk along surveying it.
In use at a saltwater beach the speed of tracking in beach GB mode is very fast, and if you are at a beach with black sand then the display can be very active. In some sense a single freq VLF is being asked to GB at two spots on a phase curve about 90deg apart at the same time. Whereas a dual or multi-freq can accomplish this in much better fashion.
While testing the new small coils I did take them into the ocean, and on my way into and out of the water passed over the area of the beach where tiny streams and puddles/pools are. For most detectors this can be one of the noisiest parts of the beach as the coil swings over water and then over sand. Even my Fisher CZ-20 8 inch coil can be noisy in these areas as I generally run that bad boy just flat out with sensitivity set at 10(max). So viscerally I knew what to expect, but having always had larger coils on my machines for beach use I could never really isolate the puddle portions from the elevated sand spots.
But having the small coil on the X-machines in auto-tracking and watching the GB change as I walked really clarified this for me. The X-70 got noisier and the GB display really started to rocket around as the machine tried to keep up with the insanity I was forcing on it. Those repeated fast transitions of going from highly magnetic black sand to pure saltwater never allowed the machine to achieve any sort of GB stasis. Then light dawns on marble head, what happens if we keep the coil hovering only over the puddle for 3-4 seconds and then only over the sand for 3-4 seconds. Ah, peace, quiet, and becoming one with the Force.
Now I could hunt those areas quietly with a single freq VLF by exercising a little more intelligence in coil positioning.
But, sadly then my curiosity factor set in which for me usually means more work ahead to better understand what I am seeing. I wanted to understand better what had greater impact on the GB of the machine when presented with magnetic and conductive ground conditions.
As Steve H. says "Science Project Time"!!!!
Methodology:
To simulate what is noted to be the average salinity of ocean saltwater ,50 grams of table salt was mixed with 1 liter of warm water. This was poured into a plastic bowl slightly over 9 inches in diameter which yielded a 1.5 inch deep saltwater surface. The bowl was then placed on top of a plastic bin 20 inches high located outdoors. The X70 was noise canceled for each coil and sensitivity was set at
In use at a saltwater beach the speed of tracking in beach GB mode is very fast, and if you are at a beach with black sand then the display can be very active. In some sense a single freq VLF is being asked to GB at two spots on a phase curve about 90deg apart at the same time. Whereas a dual or multi-freq can accomplish this in much better fashion.
While testing the new small coils I did take them into the ocean, and on my way into and out of the water passed over the area of the beach where tiny streams and puddles/pools are. For most detectors this can be one of the noisiest parts of the beach as the coil swings over water and then over sand. Even my Fisher CZ-20 8 inch coil can be noisy in these areas as I generally run that bad boy just flat out with sensitivity set at 10(max). So viscerally I knew what to expect, but having always had larger coils on my machines for beach use I could never really isolate the puddle portions from the elevated sand spots.
But having the small coil on the X-machines in auto-tracking and watching the GB change as I walked really clarified this for me. The X-70 got noisier and the GB display really started to rocket around as the machine tried to keep up with the insanity I was forcing on it. Those repeated fast transitions of going from highly magnetic black sand to pure saltwater never allowed the machine to achieve any sort of GB stasis. Then light dawns on marble head, what happens if we keep the coil hovering only over the puddle for 3-4 seconds and then only over the sand for 3-4 seconds. Ah, peace, quiet, and becoming one with the Force.
Now I could hunt those areas quietly with a single freq VLF by exercising a little more intelligence in coil positioning.But, sadly then my curiosity factor set in which for me usually means more work ahead to better understand what I am seeing. I wanted to understand better what had greater impact on the GB of the machine when presented with magnetic and conductive ground conditions.
As Steve H. says "Science Project Time"!!!!
Methodology:
To simulate what is noted to be the average salinity of ocean saltwater ,50 grams of table salt was mixed with 1 liter of warm water. This was poured into a plastic bowl slightly over 9 inches in diameter which yielded a 1.5 inch deep saltwater surface. The bowl was then placed on top of a plastic bin 20 inches high located outdoors. The X70 was noise canceled for each coil and sensitivity was set at
