Critterhunter
New member
Frank, thanks for the info. So I would assume by the sound of it you can null the coil pretty well with the TX/RX overlap in the center? Maybe more fuzzy to get things precise than using a small null loop, but possible? I always read it was far easier to balance the TX/RX windings in a DD than a concentric, than that a DD was far less picky about perfect windings alignment.
Far as the smaller trash coils go for the BBS unit, owned the 5.5" S-5 and wasn't happy with my experiences in terms of it's left/right separation. To me, it *appeard* not nearly as sharp of a DD line as any of my other much larger coils. No doubt though it will shine in terms of length wise separation.
The Excelerators? There was at one time both the 5 and 6" versions for the BBS units. The 6" is very hard to find for the BBS models as compared to the FBS units, because it wasn't carried very long in the US. The 5" model is no longer carried in US markets either, and even if it was I've dug up enough field reports on it to not be too impressed. Seems the 6" is the favored trash coil for the FBS units, with outstanding separation while still punching deep.
Just recently picked up a new eight inch Tornado, which is only 7.25" in actual size. I had read outstanding reports of it's separation, being a good bit smaller than typical true 8 or 9" sized "trash" coils on most machines. I've also heard of depth reports on a coin with it for some in some soils approaching 10 to 12", which is fantastic, at least in some soils. Read of one guy who used it at a "dead" trasy site in like I think a 12x12 foot area for several hours and ended up with numerous silvers where he was sure none existed anymore by the sound of it.
I've only used the 8" Tornado once since the weather has been bad since I got it, but in that short hours time in an iron mine field I've beat to death with numerous machines and coils over many years I managed to pull two copper memorials in the 4 or 5" range masked badly by a "ring" of trash around them. One had a large piece of iron right near it that I'm sure would glare any larger coil blind not to see that coin.
Seems this little odd shaped sub-8" coil has the ability to unmask well, yet still enough size to punch super deep to see a deep coin in the midst of say a 8" diameter of trash. That's where I think it'll shine and am looking forward to using it at long since "dead" high trash sites. The 12x10 will separate left/right wise like no coil I ever used, but no doubt if the trash is ringed around a coin in say a 8" diameter only a sub-8" coil will see it unless you hit the coin at just the right angle to avoid all the surrounding trash with the DD line. This is where I think this little coil might do some damage, wiithout the need to grid a spot from numerous angles as much.
All this said, I still want to build a extreme sniper coil, for say super heavy trash or working right up against fence lines. That's also why I'm shooting for a 4" or sub that length, and perhaps a 2 to 3" width. I can find nothing commercial for any machine this small (?) that I have found. Smallest I've seen is a 4.5" round DD for the Garretts. Yes, not sure if a DD can be built in a 4x3" size or even smaller, but only one way to find out I guess. Who knows, with more time on this 8" Tornado I might find it'll snug right up against fence lines and posts like I want, and also it's separation in heavy trash or iron will be so good that I see no need for yet a smaller coil. More time to sort that out, but no doubt a extremely small sniper coil will also have it's place in some situations.
Thanks again to everybody for all their input. I'll report back on this project when I have some useful info to share...
Far as the smaller trash coils go for the BBS unit, owned the 5.5" S-5 and wasn't happy with my experiences in terms of it's left/right separation. To me, it *appeard* not nearly as sharp of a DD line as any of my other much larger coils. No doubt though it will shine in terms of length wise separation.
The Excelerators? There was at one time both the 5 and 6" versions for the BBS units. The 6" is very hard to find for the BBS models as compared to the FBS units, because it wasn't carried very long in the US. The 5" model is no longer carried in US markets either, and even if it was I've dug up enough field reports on it to not be too impressed. Seems the 6" is the favored trash coil for the FBS units, with outstanding separation while still punching deep.
Just recently picked up a new eight inch Tornado, which is only 7.25" in actual size. I had read outstanding reports of it's separation, being a good bit smaller than typical true 8 or 9" sized "trash" coils on most machines. I've also heard of depth reports on a coin with it for some in some soils approaching 10 to 12", which is fantastic, at least in some soils. Read of one guy who used it at a "dead" trasy site in like I think a 12x12 foot area for several hours and ended up with numerous silvers where he was sure none existed anymore by the sound of it.
I've only used the 8" Tornado once since the weather has been bad since I got it, but in that short hours time in an iron mine field I've beat to death with numerous machines and coils over many years I managed to pull two copper memorials in the 4 or 5" range masked badly by a "ring" of trash around them. One had a large piece of iron right near it that I'm sure would glare any larger coil blind not to see that coin.
Seems this little odd shaped sub-8" coil has the ability to unmask well, yet still enough size to punch super deep to see a deep coin in the midst of say a 8" diameter of trash. That's where I think it'll shine and am looking forward to using it at long since "dead" high trash sites. The 12x10 will separate left/right wise like no coil I ever used, but no doubt if the trash is ringed around a coin in say a 8" diameter only a sub-8" coil will see it unless you hit the coin at just the right angle to avoid all the surrounding trash with the DD line. This is where I think this little coil might do some damage, wiithout the need to grid a spot from numerous angles as much.
All this said, I still want to build a extreme sniper coil, for say super heavy trash or working right up against fence lines. That's also why I'm shooting for a 4" or sub that length, and perhaps a 2 to 3" width. I can find nothing commercial for any machine this small (?) that I have found. Smallest I've seen is a 4.5" round DD for the Garretts. Yes, not sure if a DD can be built in a 4x3" size or even smaller, but only one way to find out I guess. Who knows, with more time on this 8" Tornado I might find it'll snug right up against fence lines and posts like I want, and also it's separation in heavy trash or iron will be so good that I see no need for yet a smaller coil. More time to sort that out, but no doubt a extremely small sniper coil will also have it's place in some situations.
Thanks again to everybody for all their input. I'll report back on this project when I have some useful info to share...
