BarnacleBill
New member
Previous posts have covered the pictures, sizes, & styles etc. so I won't cover those aspects. Before continuing, keep in mind that various individuals with differing hunting styles and geographic locations were asked to examine the coils. I was not aware of who any of the other testers were until after the tests were concluded. i.e. until his recent post I was not aware wpaxt(Bill) had any of the coils and there are probably others that I will never be aware of. I am quite satisfied when testing is done in this manner as there is no cross pollination of ideas, however keep in mind that this may lead to a composite view and not one that is smoothly integrated. So don't be surprised by some contradictions where the reports don't all fit neatly into a nice & tidy intellectual box. In a nutshell, please don't latch onto an isolated portion and go running off with your hair on fire making some ridiculous positive or negative claims about what I've written.
Air Tests
Yeah I know, but you have a certain crowd that looks forward to the tale of the tape in air. But sadly, these air test will be totally blown out of the water by the Saltwater Testing. So sorry, if you put a lot of stock in air tests, they will be crushed in short order.
[attachment 65466 airt.gif]
Land & Freshwater Testing
Being that the main use of these small coils will be detecting in trash I decided to spend most of my time in the iron fields. I have available locations where there is a consistent ramp up of iron within thirty feet. All you have to do is walk in a straight line from a low iron area to one where, if you were wearing magnets on your shoes you'd be stuck in place. The iron is thick enough that a mere 2 inch wiggle of even these small coils reports two adjacent iron targets The low iron areas were used to GB, check Noise etc. etc. Then a slow deliberate march towards the iron pile checking separation, overload etc as conditions worsened. Each coil was tested several times over many days splitting the time equally and retesting paths already traveled by the other coil. Directions were reversed and then cross paths etc to see what more could be extracted. The truly nasty area in question is about 20ftx20ft and has been covered dozens of times by various machines and coil combinations, and as such is NOT virgin ground.
I found that I liked the HF DD better for several reasons:
1. I hunt for low conductors and the HF is better for that.
2. I found the separation to be better.
3. I DID use pinpoint and liked it better on the HF DD. Because the coils do run pretty hot, the pinpoint function is really hot, so I ended up raising the coils during pinpoint which I found to be VERY EFFECTIVE. As a matter of fact I normally don't use the pinpoint function but would with these coils in very heavy iron.
The following should be read with the following in mind, and concerning the 6 inch CC MF coil only, and not the HF DD. I am hunting in my soil matrix, not yours, so do not assume you will ever see this, I am simply making note of it in case you run across it. So take this as a hunting tip should you see the same thing in your soil. This kind of follows along the lines of my volcano with a moat around it experiment. Which is, take any detector you like, bury a U.S. nickel at 4 inches in perfectly smooth dry freshwater sand. Swing the coil over it and you should get a good solid nickel ID. Now dig a nice circular moat 10 inches deep leaving about a six inch diameter column in the middle with the nickel still in it at 4 inches. Re-swing coil and presto, the nickel just turned to iron.
So what I found is that depressions in my soil matrix can cause iron items like nails to wrap around to 46-48 ID. If you smooth the sand over, then the iron falls back into the minus iron. Occasionally a heavily encrusted nail at a severe angle or completely vertical would act the same over smooth sand. Now how to deal with it. In all the above mentioned cases the target had a very specific signature, which was: Visual ID of 46-48, 3 to 4 arrows deep being reported and a very very soft audio response. It's hard to convey how soft the audio is, think marshmallow. If this were a U.S. quarter or silver ring at the reported depth, then the response would be very sharp. In a very short period of time I was able to call these targets easily and dug several just to confirm.
During testing I also covered an area which is a walkway to a beach which about 10ft wide by 20 ft. In the past it has yielded some old silver and I usually hit it every spring to see if the frost has moved anything. There's a pretty fair amount of iron and I've also hit it with several machines and coils. I was using the six inch MF CC when I hit a very strong and clear target. Out popped a real surprise which I have no rational explanation for except that other coils may have been keying on some deep iron.
[attachment 65467 canoe.jpg]
The piece is an ID plate off of a Charles River "1915" model canoe manufactured by the Kennebec Boat & Canoe company. For those not familiar with the "Charles River" it is the major river in Boston, MA USA. The canoe was only produced from 1910 to 1916 and it's too bad someone put a bullet through it.
A final note is that I located some charcoal on the surface which neither coil responded to, which is very good for many of us.
Some off the variety of items found are shown below. Keep in mind I was digging all sorts of targets good and bad to understand how the coils were acting.
[attachment 65470 stuff.jpg]
Prospecting Testing
I am NOT a prospector and don't even play one on TV. But since I figured the HF DD would be aimed at this market I thought I would give it a go. Though the area I live in is mountainous and there is some gold found in streams within 50 miles, it is not noted as there being any near me. The gold that is found in the above mentioned streams is done only with dredges where you can get down to bedrock and consists of flakes for the most part. Nonetheless I packed up my gear and off I went to locate a roadside stream on the slope off an old volcano where quartz and iron laden basalt is common. I had found an area of a stream with a significant vertical drop , but it was spring runoff time, the water high, and absolutely ripping. This being the case I was restricted to wading in the pools between boulders at the edge of the stream, with no way to get to the center of the stream. The HF DD did quite well in taking the abuse of being knocked into rocks and submerged.
I was running the X-70 Prospecting mode with Tracking On and the Sensitivity up in the high 20's. I did get some falsing on the larger pieces of the iron laden basalt which didn't alarm me, in that, using the ground measurement feature of the X70 they read in the 400,000+ range which is quite extreme. So what did I find? Well several very tiny aluminum shards at up to 2 inches deep. And when I say tiny I mean tiny, like if you clipped off a quarter inch long by 1/64 inch wide piece of your little finger nail. I had a heck of a time just trying to find them in a little pile of sand in my hand 'cause the Vibraprobe didn't stand a chance.
Saltwater Testing
First, who in their right mind would use a 6 inch coil to hunt on a saltwater beach? Well believe or not there is one definite circumstance where it would be helpful, and another where you may avail yourself of the smaller coil. This is likely geographically based, but some of the beaches I frequent have piers that when you hunt under or near them are filled with iron. Also many of these have burnt down several times or been destroyed by storms leading to high iron infestation. I have also noted by various posts on forums that cities with boardwalks suffer some of the same conditions.
The second circumstance is rarer and I would not specifically buy a coil to cover it, but if I had one handy, use it as needed. In the photo below is a hot spot on a beach I hunt from time to time. These usually appear after storms and are very temporary in nature, that being, by the next tide change they are gone. This particular beach tends to be a very flat beach with very large distances from high to low tide, so that, the slight shelving seen to the right along the snow line is a significant clue. Also the presence of the larger stones peeking through on this beach is a good sign. When this photo was taken I had gridded this area after having zig-zagged approximately 1/2 mile before hitting it. The ocean being indiscriminate the area was filled with iron and good targets, so in this instance a small coil would have been helpful. Also being at the top of the tide line the saltwater has drained, and this is a transition point where a single freq VLF can come into it's own as you work back and forth across the high tide line.
[attachment 65469 grid3.jpg]
Now down to the business at hand. I traveled to the ocean on the outgoing tide having chosen a beach with black sand. The amount or mix of black sand changes with every tide. So please keep in mind that this is a snapshot in time and the depth figures should be viewed relative to one another, not absolute. I decided to take three U.S. nickels and create a test garden in very soupy sand. First an area was checked for any targets with a Fisher CZ-20, then swept with the X70 with HF elliptical. I also checked the homogeneity of the ground phase by monitoring the X70 in beach tracking mode.
After the preliminary work, the three nickels were spaced 24 inches apart and location marked with a colored cellophane topped toothpick. There were three approximate depths chosen, 4, 6, & 8 inches. I felt the 8 incher was a little ridiculous based on previous tests with other detectors including multi-freqs., but I threw it in their for giggles, and as a control. Now digging the holes was a story in itself, the sand was saturated with water and draining, so as soon as sand was removed the hole filled in immediately. By the time I got to the 8 incher I was saying bad things about the sand's Mother. However I would jam the nickel in the hole and hold it in place with the squared off end of a wooden twelve inch ruler. Therefore I believe we are within a half inch tolerance.
Before looking at the table below I have to say I was flabbergasted by what the small HF DD accomplished. I just didn't believe my ears or eyes at first, to the point that I went back to my car to retrieve another sample of each coil and to re-check them both. The HF DD held up to the initial response. One thing to note though is that if using tracking when you approach the 8 inch deep nickel one would need to switch to manual or it'll GB out in 3 to 4 swings. But no big deal because that's the method I run the X70 with on saltwater anyways. Some of it's performance has to be related to the higher sensitivity level it can be run at over the standard sized coils with typically are in the 15 range on this beach. But that said, the small MF CC could be run at similar levels. Yep that level of performance is the stuff of urban legends, sensitivity at 66%(20) with a six inch coil hitting a nickel in the 8 inch range on a black sand beach. Does this mean that you will find the same type of performance in a particular high mineral content area? That I can't say, it may or may not. And lastly do I suggest you go running off and cover a 2 mile long beach with a six inch coil? Of course not! But the results were certainly interesting!
[attachment 65468 clip1.gif]
HH
BarnacleBill
Air Tests
Yeah I know, but you have a certain crowd that looks forward to the tale of the tape in air. But sadly, these air test will be totally blown out of the water by the Saltwater Testing. So sorry, if you put a lot of stock in air tests, they will be crushed in short order.
[attachment 65466 airt.gif]
Land & Freshwater Testing
Being that the main use of these small coils will be detecting in trash I decided to spend most of my time in the iron fields. I have available locations where there is a consistent ramp up of iron within thirty feet. All you have to do is walk in a straight line from a low iron area to one where, if you were wearing magnets on your shoes you'd be stuck in place. The iron is thick enough that a mere 2 inch wiggle of even these small coils reports two adjacent iron targets The low iron areas were used to GB, check Noise etc. etc. Then a slow deliberate march towards the iron pile checking separation, overload etc as conditions worsened. Each coil was tested several times over many days splitting the time equally and retesting paths already traveled by the other coil. Directions were reversed and then cross paths etc to see what more could be extracted. The truly nasty area in question is about 20ftx20ft and has been covered dozens of times by various machines and coil combinations, and as such is NOT virgin ground.
I found that I liked the HF DD better for several reasons:
1. I hunt for low conductors and the HF is better for that.
2. I found the separation to be better.
3. I DID use pinpoint and liked it better on the HF DD. Because the coils do run pretty hot, the pinpoint function is really hot, so I ended up raising the coils during pinpoint which I found to be VERY EFFECTIVE. As a matter of fact I normally don't use the pinpoint function but would with these coils in very heavy iron.
The following should be read with the following in mind, and concerning the 6 inch CC MF coil only, and not the HF DD. I am hunting in my soil matrix, not yours, so do not assume you will ever see this, I am simply making note of it in case you run across it. So take this as a hunting tip should you see the same thing in your soil. This kind of follows along the lines of my volcano with a moat around it experiment. Which is, take any detector you like, bury a U.S. nickel at 4 inches in perfectly smooth dry freshwater sand. Swing the coil over it and you should get a good solid nickel ID. Now dig a nice circular moat 10 inches deep leaving about a six inch diameter column in the middle with the nickel still in it at 4 inches. Re-swing coil and presto, the nickel just turned to iron.
So what I found is that depressions in my soil matrix can cause iron items like nails to wrap around to 46-48 ID. If you smooth the sand over, then the iron falls back into the minus iron. Occasionally a heavily encrusted nail at a severe angle or completely vertical would act the same over smooth sand. Now how to deal with it. In all the above mentioned cases the target had a very specific signature, which was: Visual ID of 46-48, 3 to 4 arrows deep being reported and a very very soft audio response. It's hard to convey how soft the audio is, think marshmallow. If this were a U.S. quarter or silver ring at the reported depth, then the response would be very sharp. In a very short period of time I was able to call these targets easily and dug several just to confirm.
During testing I also covered an area which is a walkway to a beach which about 10ft wide by 20 ft. In the past it has yielded some old silver and I usually hit it every spring to see if the frost has moved anything. There's a pretty fair amount of iron and I've also hit it with several machines and coils. I was using the six inch MF CC when I hit a very strong and clear target. Out popped a real surprise which I have no rational explanation for except that other coils may have been keying on some deep iron.
[attachment 65467 canoe.jpg]
The piece is an ID plate off of a Charles River "1915" model canoe manufactured by the Kennebec Boat & Canoe company. For those not familiar with the "Charles River" it is the major river in Boston, MA USA. The canoe was only produced from 1910 to 1916 and it's too bad someone put a bullet through it.
A final note is that I located some charcoal on the surface which neither coil responded to, which is very good for many of us.
Some off the variety of items found are shown below. Keep in mind I was digging all sorts of targets good and bad to understand how the coils were acting.
[attachment 65470 stuff.jpg]
Prospecting Testing
I am NOT a prospector and don't even play one on TV. But since I figured the HF DD would be aimed at this market I thought I would give it a go. Though the area I live in is mountainous and there is some gold found in streams within 50 miles, it is not noted as there being any near me. The gold that is found in the above mentioned streams is done only with dredges where you can get down to bedrock and consists of flakes for the most part. Nonetheless I packed up my gear and off I went to locate a roadside stream on the slope off an old volcano where quartz and iron laden basalt is common. I had found an area of a stream with a significant vertical drop , but it was spring runoff time, the water high, and absolutely ripping. This being the case I was restricted to wading in the pools between boulders at the edge of the stream, with no way to get to the center of the stream. The HF DD did quite well in taking the abuse of being knocked into rocks and submerged.
I was running the X-70 Prospecting mode with Tracking On and the Sensitivity up in the high 20's. I did get some falsing on the larger pieces of the iron laden basalt which didn't alarm me, in that, using the ground measurement feature of the X70 they read in the 400,000+ range which is quite extreme. So what did I find? Well several very tiny aluminum shards at up to 2 inches deep. And when I say tiny I mean tiny, like if you clipped off a quarter inch long by 1/64 inch wide piece of your little finger nail. I had a heck of a time just trying to find them in a little pile of sand in my hand 'cause the Vibraprobe didn't stand a chance.
Saltwater Testing
First, who in their right mind would use a 6 inch coil to hunt on a saltwater beach? Well believe or not there is one definite circumstance where it would be helpful, and another where you may avail yourself of the smaller coil. This is likely geographically based, but some of the beaches I frequent have piers that when you hunt under or near them are filled with iron. Also many of these have burnt down several times or been destroyed by storms leading to high iron infestation. I have also noted by various posts on forums that cities with boardwalks suffer some of the same conditions.
The second circumstance is rarer and I would not specifically buy a coil to cover it, but if I had one handy, use it as needed. In the photo below is a hot spot on a beach I hunt from time to time. These usually appear after storms and are very temporary in nature, that being, by the next tide change they are gone. This particular beach tends to be a very flat beach with very large distances from high to low tide, so that, the slight shelving seen to the right along the snow line is a significant clue. Also the presence of the larger stones peeking through on this beach is a good sign. When this photo was taken I had gridded this area after having zig-zagged approximately 1/2 mile before hitting it. The ocean being indiscriminate the area was filled with iron and good targets, so in this instance a small coil would have been helpful. Also being at the top of the tide line the saltwater has drained, and this is a transition point where a single freq VLF can come into it's own as you work back and forth across the high tide line.
[attachment 65469 grid3.jpg]
Now down to the business at hand. I traveled to the ocean on the outgoing tide having chosen a beach with black sand. The amount or mix of black sand changes with every tide. So please keep in mind that this is a snapshot in time and the depth figures should be viewed relative to one another, not absolute. I decided to take three U.S. nickels and create a test garden in very soupy sand. First an area was checked for any targets with a Fisher CZ-20, then swept with the X70 with HF elliptical. I also checked the homogeneity of the ground phase by monitoring the X70 in beach tracking mode.
After the preliminary work, the three nickels were spaced 24 inches apart and location marked with a colored cellophane topped toothpick. There were three approximate depths chosen, 4, 6, & 8 inches. I felt the 8 incher was a little ridiculous based on previous tests with other detectors including multi-freqs., but I threw it in their for giggles, and as a control. Now digging the holes was a story in itself, the sand was saturated with water and draining, so as soon as sand was removed the hole filled in immediately. By the time I got to the 8 incher I was saying bad things about the sand's Mother. However I would jam the nickel in the hole and hold it in place with the squared off end of a wooden twelve inch ruler. Therefore I believe we are within a half inch tolerance.
Before looking at the table below I have to say I was flabbergasted by what the small HF DD accomplished. I just didn't believe my ears or eyes at first, to the point that I went back to my car to retrieve another sample of each coil and to re-check them both. The HF DD held up to the initial response. One thing to note though is that if using tracking when you approach the 8 inch deep nickel one would need to switch to manual or it'll GB out in 3 to 4 swings. But no big deal because that's the method I run the X70 with on saltwater anyways. Some of it's performance has to be related to the higher sensitivity level it can be run at over the standard sized coils with typically are in the 15 range on this beach. But that said, the small MF CC could be run at similar levels. Yep that level of performance is the stuff of urban legends, sensitivity at 66%(20) with a six inch coil hitting a nickel in the 8 inch range on a black sand beach. Does this mean that you will find the same type of performance in a particular high mineral content area? That I can't say, it may or may not. And lastly do I suggest you go running off and cover a 2 mile long beach with a six inch coil? Of course not! But the results were certainly interesting!
[attachment 65468 clip1.gif]
HH
BarnacleBill
You two have done a remarkable job of describing your process and results. Thanks again. HH Randy
