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A Coil Video


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I just happened across this video and thought I'd post it.  

I still find any of these simple videos to not include 'off the coil' sensing of a target.  They show field restricted to just the edges of the coil.  We all know the field is larger than the coil.  I say I'm drawn to some of my targets like a moth to a flame.  Some days I am better at this than others.

It's the FRINGE that can make a difference.

 

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11 minutes ago, mn90403 said:

They show field restricted to just the edges of the coil

I remember this video!

Actually not so much to describe any kind of coil to someone, but If I'm correct, the picture right now visible in the screen is a concentric one.

Way too optimistic shape for the  coil emitted field...Not to mention the invisible upperside...

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On 7/4/2020 at 12:58 AM, mn90403 said:

I just happened across this video and thought I'd post it.  

I still find any of these simple videos to not include 'off the coil' sensing of a target.  They show field restricted to just the edges of the coil.  We all know the field is larger than the coil.  I say I'm drawn to some of my targets like a moth to a flame.  Some days I am better at this than others.

It's the FRINGE that can make a difference.

 

The area under a coil where a target can be detected can be the size of the coil, or larger, or smaller. It depends on the target size. A small ear ring may only signal in an area the size of a tea cup under a 10” coil.

“Fringe“ in my mind is nothing more than “edge of detection depth” where the target fades out and gets weak. Cut a grapefruit in half and put a small plate on top of one half. The plate is the coil. The grapefruit half under the plate is the “detection area“ and the skin or rind is the “fringe detection area.”

Whether or not this area can be sensed by an operator depends on whether or not you use modulated audio. Some detectors boost all targets to a solid beep where everything sounds strong. Binary audio. Beep or not. This is good for people with poor hearing. There are no discernible fringe targets since all targets sound the same. They are full strength beep until they get too weak to detect, then nothing.

Modulated audio keys the volume and/or pitch to the signal strength. Weak targets have weak audio, strong targets have strong audio. So called fringe targets are the ones that deliver a bare whisper most people walk past. These are larger targets right at the edge of detection depth, or very small targets that are very weak, even if only an inch deep. If I ever say “I dug a whisper target” or a “ very weak target”, it is the same as saying “I dug a fringe area target.”

Another way to look at it is that in order to master the detection of really small items, you have to master hunting fringe targets. People new to nugget detecting are often poor at this, and can only hear strong targets. Part of the problem is the many weak ground signals that confuse them, so they only go for the obvious targets. Look in their pouch, and all they have is large stuff, which when nugget detecting usually means trash. To do well a person has to develop an ear for softer “smaller” sounds, that mean small gold nuggets, or large deep nuggets that barely whisper. In any nugget patch, the first gold to go away are the nuggets with  big, easy signals.

I personally do not like to to use a detector without modulated audio. Binary audio delivers little useable target information, and so for me I prefer modulated full tones for maximum target information. Though if you are digging everything anyway, a case can be made for monotone binary audio. Beep, dig.

Long story short, showing the detection area as the same size as the coil is not automatically inaccurate. It depends on the target size used in the example, and by definition you have to assume they size they used produced the detection area displayed. They also need not get into “fringe” areas if the model used employs binary audio, which produces sharp, defined edges to the detection area, instead of the “fuzzy” edges seen with modulated audio. The fuzzy zone being the fringe area.

DD vs Concentric Coils

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41 minutes ago, Steve Herschbach said:

I personally do not like to to use a detector without modulated audio. Binary audio delivers little useable target information, and so for me I prefer modulated full tones for maximum target information. Though if you are digging everything anyway a case can be made for monotone binary audio. Beep, dig.

To this point, I wish that ML had provided the option to select the gold mode modulated audio as an option on the other modes and had provided the option to select tone ID audio with the gold modes.  My solution is to just switch between gold mode and the preferred non-gold search mode profile suitable for the my target objectives and site conditions, as necessary, using the user profile slot. The ability to quickly switch to the user profile slot is an underappreciated bonus feature of the 800 (though I wish the button resided on the face of the control panel) as well as the common misunderstanding that gold mode is primarily only useful for prospecting.

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On 7/4/2020 at 11:18 AM, Steve Herschbach said:

Another way to look at it is that in order to master the detection of really small items, you have to master hunting fringe targets. People new to nugget detecting are often poor at this, and can only hear strong targets. Part of the problem is the many weak ground signals that confuse them, so they only go for the obvious targets. Look in their pouch, and all they have is large stuff, which when nugget detecting usually means trash. To do well a person has to develop an ear for softer “smaller” sounds, that mean small gold nuggets, or large deep nuggets that barely whisper. In any nugget patch, the first gold to go away are the nuggets with  big, easy signals.

(Quoting same section as Phrunt did, but coming from a different angle.)

I find this statement accurate as well for A) coin hunting in trashy sites (and that's all sites where I've found old coins) and B) even for experienced detectorists, not just 'beginners'.  Now I elaborate:

A) the bigger targets (usually 'trash' but this just means the targets you aren't after) slam your brain hard.  It takes concentration to ignore them, and in some cases it can help to just remove them.  For example, most (not all) strong hits in the 19-24 zone of the Equinox (you know the zone for your detector) are either Zinc pennies or aluminum screwcaps.  But those are typically close to the surface and quickly removed, so even if you're only after, for example, higher TID's you may benefit from removing them anyway.  This allows two things -- 1) deeper targets which are truly masked by the large target now have a better chance of being heard/detected, and 2) with the loud target out of the way, your brain can more easily pick up the subtler weaker target.

B) I notice that I tend to be more attune to all sounds when I first start out.  As the hunt progresses, mental fatigue sets in.  Being able to recognize the latter and refocus helps alleviate that to a certain extent.  Sometimes a short water/snack break or even just sit-down-and-rest break helps.  But even then I'm not as sharp as when I first started.  I'm confident this has cost me some good (but soft/subtle) targets later in my hunts.

You often see, and for good reason, the advice to recheck a hole after recovering a target.  What you read/hear less often is to take step back and reswing over the entire left-to-right swath you have just detected before proceding forward to unsearched ground.  Especially after removing a large target (treasure or trash) you give your brain a chance to notice a signal that might have been there all along but from which you were distracted by the loud one. 

All of this is related to the reason (besides unmasking) why hunting a previously hunted site can sometimes pay unexpected dividends.  But there is also the possibility that the previous detectorists just didn't get their coils (centered) over that good target.  Thorough ground coverage is not as easy as mowing the lawn!

Of course some people have just better trained themselves to listen carefully and distinguish, and maybe these techniqus are unnecessary wastes of time for them.  I do know they've helped me.

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18 hours ago, GB_Amateur said:

(Quoting same section as Phrunt did, but coming from a different angle.)

I find this statement accurate as well for A) coin hunting in trashy sites (and that's all sites where I've found old coins) and B) even for experienced detectorists, not just 'beginners'.  Now I elaborate:

A) the bigger targets (usually 'trash' but this just means the targets you aren't after) slam your brain hard.  It takes concentration to ignore them, and in some cases it can help to just remove them.  For example, most (not all) strong hits in the 19-24 zone of the Equinox (you know the zone for your detector) are either Zinc pennies or aluminum screwcaps.  But those are typically close to the surface and quickly removed, so even if you're only after, for example, higher TID's you may benefit from removing them anyway.  This allows two things -- 1) deeper targets which are truly masked by the large target now have a better chance of being heard/detected, and 2) with the loud target out of the way, your brain can more easily pick up the subtler weaker target.

B) I notice that I tend to be more attune to all sounds when I first start out.  As the hunt progresses, mental fatigue sets in.  Being able to recognize the latter and refocus helps alleviate that to a certain extent.  Sometimes a short water/snack break or even just sit-down-and-rest break helps.  But even then I'm not as sharp as when I first started.  I'm confident this has cost me some good (but soft/subtle) targets later in my hunts.

You often see, and for good reason, the advice to recheck a hole after recovering a target.  What you read/hear less often is to take step back and reswing over the entire left-to-right swath you have just detected before proceding forward to unsearched ground.  Especially after removing a large target (treasure or trash) you give your brain a chance to notice a signal that might have been there all along but from which you were distracted by the loud one. 

All of this is related to the reason (besides unmasking) why hunting a previously hunted site can sometimes pay unexpected dividends.  But there is also the possibility that the previous detectorists just didn't get their coils (centered) over that good target.  Thorough ground coverage is not as easy as mowing the lawn!

Of course some people have just better trained themselves to listen carefully and distinguish, and maybe these techniqus are unnecessary wastes of time for them.  I do know they've helped me.

Very true and perhaps the main reason for my decades of success .... along with using a smaller-size coil and working a site slowly-and-methodically.  Having patience helps us along the way, and that's what it takes to do what you related. 

Monte

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