LawrencetheMDer
Bronze Member
- Joined
- Feb 22, 2014
- Messages
- 1,142
- Reaction score
- 2,979
- Golden Thread
- 0
- Location
- Ohio and Florida
- Detector(s) used
- Minelab Manticore w M8, M11 and M15 coils, , Minelab CTX3030 w 11" and 17" DD coils,
Minelab Excalibur II w 10" coil, Equinox 800 (4) w 11" and 15" coils,
Pointers; Garrett Carrot, Pro Find 35,
- Primary Interest:
- Beach & Shallow Water Hunting
I was watching a video of a local beach to assess environmental conditions and population density. As I was watching the beach, I noticed a Metal Detectorist about ¼ mile away. Immediately, I recognized the infamous pendulum swing – from a ¼ mile away! To those new to the hobby, errr, obsession, the pendulum swing, as the name suggests, is when the coil is swung as if it were a pendulum in front of you – coil at ground level on the center line (e.g., looking straight ahead) and the coil “swings” progressively further and further from the ground as it moves away from the center line. [I believe this type of coil swing developed early in the hobby when detectors lacked arm cuffs and thus were swung in a pendulum fashion.] In contrast, a circular swing is defined as moving the coil a constant level above the ground as you swing the coil left and right. In a sense, with a circular swing the coil moves around you (for illustration of a circular swing, see discussion at: https://www.treasurenet.com/threads...-to-heal-stride-while-metal-detecting.719353/
Since the coil is always the same distance from the ground the Detectorist naturally performs a semi-circular movement. Both types of swing can be exaggerated in an open area – in my case open beach. Of course in closed-in or weeded areas, both types of swing would be limited.
The video observation got me thinking about the surface coverage lost to the metal detector coil and, of course, lost target opportunities when a pendulum swing is performed vs a circular swing.
So I took “scientific measurements” (lol, set-up a tape measure in front of me) and assessed my swing in terms of lateral left-right movement of the Manticore M15 coil (width about the same as 11” coil). For me, I try to hug the ground throughout the swing and try to avoid exceeding about 2” or so above the ground. I also keep the coil parallel to the ground by periodically skimming the sand. I also swing the coil further left and right than most Detectorist; I estimate the angle covered with my elbow the apex at 100 deg. In terms of lateral movement perpendicular to my line of sight, I cover roughly 5 ft with each swing. Individual differences exist.
Next, I tried to mimic a pendulum swing with my coil. For calculation purposes only, I assumed a target can be detected at 5” from the coil edge. So once the coil’s lower edge was 5” above the ground it would signify no detection ability. I found that the pendulum swing, for me, covered about 3 ft laterally before the coil exceeded 5” and would no longer detect a target at the surface. At this point it should be noted that if you have a small circular swing (e.g., 40 deg), the circular swing could equal the pendulum swing in which case...Never mind.
Long story short – swinging a coil in the pendulum fashion compared to the circular fashion would cause the Detectorist (Me) to miss approximately 40% of targets per swing. Of course, everyone would be different and I’m not trying to address every situation. Mainly looking at open beach where the Detectorist can go full throttled; and from observation many do! For me, I like my swing and if you like the pendulum swing by all means continue – continue to offer me 40% of your potential but not realized finds.
Happy Hunting
Since the coil is always the same distance from the ground the Detectorist naturally performs a semi-circular movement. Both types of swing can be exaggerated in an open area – in my case open beach. Of course in closed-in or weeded areas, both types of swing would be limited.
The video observation got me thinking about the surface coverage lost to the metal detector coil and, of course, lost target opportunities when a pendulum swing is performed vs a circular swing.
So I took “scientific measurements” (lol, set-up a tape measure in front of me) and assessed my swing in terms of lateral left-right movement of the Manticore M15 coil (width about the same as 11” coil). For me, I try to hug the ground throughout the swing and try to avoid exceeding about 2” or so above the ground. I also keep the coil parallel to the ground by periodically skimming the sand. I also swing the coil further left and right than most Detectorist; I estimate the angle covered with my elbow the apex at 100 deg. In terms of lateral movement perpendicular to my line of sight, I cover roughly 5 ft with each swing. Individual differences exist.
Next, I tried to mimic a pendulum swing with my coil. For calculation purposes only, I assumed a target can be detected at 5” from the coil edge. So once the coil’s lower edge was 5” above the ground it would signify no detection ability. I found that the pendulum swing, for me, covered about 3 ft laterally before the coil exceeded 5” and would no longer detect a target at the surface. At this point it should be noted that if you have a small circular swing (e.g., 40 deg), the circular swing could equal the pendulum swing in which case...Never mind.
Long story short – swinging a coil in the pendulum fashion compared to the circular fashion would cause the Detectorist (Me) to miss approximately 40% of targets per swing. Of course, everyone would be different and I’m not trying to address every situation. Mainly looking at open beach where the Detectorist can go full throttled; and from observation many do! For me, I like my swing and if you like the pendulum swing by all means continue – continue to offer me 40% of your potential but not realized finds.
Happy Hunting
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