Trying To Find True Mono For TDI

[GeoBill]

My recollection is Reg's and then miner John's 'folded mono' design, folded single coil,  was to avoid White's patent for the dual field where "multiple coplanar wire coils of different diameters connected in series...". From what I read Miner John's coil seemed to get great reviews and in high demand. Have any other coil manufacturers followed up on either the White's or folded mono designs and were there any real advantages over the single loop mono?

[Jim in Idaho]

Bill, I think the advantage was better coverage under the coil, especially for really small gold. You are correct about getting around the patent. Now we have the spiral-wound coils which accomplish the same thing. Apparently lots of ways to skin that cat. That said, I have both a 7 1/2DF, and a straight mono 8 x 6 Sadie, and can tell very little difference between them, though if I had to choose, I'd give the very slight edge to the DF, thoughit might be my bias showing...LOL

Jim

[Mark Gillespie]

I really like the 7 1/2" DF coil.  Its found me some nice items including a gold ring.