CoilFisher
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- Jul 17, 2011
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- Metal Detecting
Anyone really notice a great difference in these vs the old concentric. Is it all just hype?
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OldeBeechnut said:My question is, Has anyone scientifically prov-en information showing the "fields" that come off of any coil, I've seen Eric Foster, Prospector Al and several others discuse but no one can measure this type of data from what I have read......... Plus would not the Matrix of the soil/sand affect this from one location to the next?
WOT in Action, deep target? 18/19 inch's possibly, no problem with pinpointing...............
http://www.youtube.com/watch?v=xInLPXijE70
Dave has stated on other forums that the drawings of coil detection fields are not accurate and we have discussed it at length on other forums.Jason in Enid said:M Scott @ FTP said:Frankn said:Jason, The concentric delivers all its transmit power through one coil set while the DD delivers 1/2 its power through each of two coil sets. That's why the concentric goes deeper. My concentric picks up at the extreme edges of the coil which means that picture is wrong because it only shows signal at the center hole. The picture is BS. Try any detector with a concentric and prove this to yourself, if that is possible. My detector will pick up a large object at 2' which tells me that little cone is BS. My comments are based on actual usage over many years not just wild mutterings pulled from the air. Frank
Frank is right-the picture is complete BS created by detector companies marketing departments. Far too many people believe the imaginary detector field because they saw it in a manufacturers catalog.....
Here are some facts from detector designer David J whom has also stated the drawings are BS;
http://www.fisherlab.com/hobby/davejohnson/searchcoils essay revised.htm
DD better depth in bad soil and concentrics are cheaper to manufacture-lots more infor if you read all his essays on the web site.
Mike
That article doesn't say anything about "pictures" being BS or anything close to it.
Geez people, are some of you REALLY that dense?!
The transmit coil puts off signal.
the metal object radiates back its own signal from the transmitted energy
the recieving coil picks up the energy
the detector compares the differences and tell you what it thinks is down there.
Now, WAKE UP! A metal object above, below, or beside a coil will still recieve and re-radiate a signal
the picture that some you are complaining about isn't a fully discriptive picture, it's a representation of DETECTION AREA for small targets, under the coil, where you will typically be seeing them.
Oh, and Frankn... if the detector wasn't seeing differences in radiated frequency, it would never detect anything. No returned signal will ever be stronger than the field from the transmit coil, therefore if it is only seeing ONE frequency, it is blind.
I'm done trying to explain such a simple concept to such dense people.
Treasure_Hunter said:M Scott @ FTP said:Frank is right-the picture is complete BS created by detector companies marketing departments. Far too many people believe the imaginary detector field because they saw it in a manufacturers catalog.....
Here are some facts from detector designer David J whom has also stated the drawings are BS;
http://www.fisherlab.com/hobby/davejohnson/searchcoils essay revised.htm
DD better depth in bad soil and concentrics are cheaper to manufacture-lots more infor if you read all his essays on the web site.
Mike
Mike you better go back and read your reference, no where in it AT ALL does he say they are BS, in fact he praises them...
"The advantages of the DD are greater depth in mineralized soil, a broad sweep pattern, and narrower target response. Its primary disadvantages from a user's point of view are multiple responses on shallow targets and poor discrimination of flat iron objects. Designing and manufacturing them is more difficult because their lack of radial symmetry makes them prone to drift which the design and the manufacturing process must minimize. Manufacturing cost is higher because the coils cannot be wound on high-speed winding equipment."
I have been using large DD coils for over 4 years, they simply rock..... I have found .06 of a gram gold rings with them, the depth is fantasitc, the foot print makes cover areas so much easier, I am have absolutely no problem pinpointing with them, or recovering multiple targets under the 15 inch footprint most of mine have......
Treasure_Hunter said:Sorry, I still disagree, I started with concentric coils and have been using DD coils for over 4 years now, I have seen the advantage they have over concentric coils......
gleaner1 said:Treasure_Hunter said:Sorry, I still disagree, I started with concentric coils and have been using DD coils for over 4 years now, I have seen the advantage they have over concentric coils......
Is the advantage the heavier weight, or the lack of depth? T-Hunter, the masses need to know.
gleaner1 said:Okay, but I still do not understand how the huge dd you use in the salt surf is better than the 8" concentric I use in the ancient amusement park in the woods. Your insults not withstanding.
Treasure_Hunter said:gleaner1 said:Okay, but I still do not understand how the huge dd you use in the salt surf is better than the 8" concentric I use in the ancient amusement park in the woods. Your insults not withstanding.
Gleamer, it wasn't meant as an insult it was a joke which is why I used the " ".... Weight is not an issue....As far as the 15 inch, my DD coils gives twice the footprint, you do not have to overlap like you do with a concentric coil and it gives more than twice the depth of an 8' concentric coil.... I have hunted city and couty parks with it and I have no problem at all with pinpointing with them nor with multiple targets under the coil, I pinpoint each target and recover it till there is nothing there.
Jason in Enid said:It is also better in mineralization because it sees less percentage of soil at any given time.
gleaner1 said:Jason in Enid said:It is also better in mineralization because it sees less percentage of soil at any given time.
Jason, how can any particular coil that sees a lesser percentage of the soil be better? By logic, that coil would therefore see less percentage of targets. How can a shallow coil be better? Replace your most beloved big dd with a concentric, slow down and re-discover tectin. This does not apply to 100% of detectorists in 100% of soils. It's a case by case situation. I get best results with concentrics, they are hot on deep crap in my mild loam and I'm not in a hurry. For others, its all dd. It's a never ending discussion.
TH .. The reason you have no problem pin pointing is you spend most of your time in the water or on a sandy beach...........................Treasure_Hunter said:Sorry, I still disagree, I started with concentric coils and have been using DD coils for over 4 years now, I have seen the advantage they have over concentric coils......
Keppy said:TH .. The reason you have no problem pin pointing is you spend most of your time in the water or on a sandy beach...........................Treasure_Hunter said:Sorry, I still disagree, I started with concentric coils and have been using DD coils for over 4 years now, I have seen the advantage they have over concentric coils......