Fender noisless same magnetic polarity on top and bottom

[the great waldo]

Hi all

Iwonder if anyone has noticed the fact that fender scn pickups have the same magnetic polarity on top as well as bottom ? Any comments?

Cheers

Andrew

[Mark Hammer]

I think you need to also ask "What's in the middle?". These would appear to be dual-coil pickups, with a slightly taller profile, and three leads. P90s have a pair of bar magnets coupled at the keeper in the middle of the pickup, with the same pole facing outward. No reason why one couldn't have a six-pak of small rare-earth mags of opposite orientation meet in the middle, such that each coil has its own set of polepieces.

[Mike Sulzer]

But if these are stacked humbuckers, and each coil has its own pole pieces, why take the trouble to put opposing magnets in between the ends of the the top and bottom pole pieces? Not only would this be hard to assemble, there would be some loss of field strength, and the bottom pole pieces do not need to be magnetized in any case. Another explanation would be that they are fed from the side (like a P-90) at the middle, so that if north is in, then both top and bottom would then be north. Presumably there is some magnetic shielding, etc, as is commonly used in modern stacked pickups, and so the overall design is not so simple to understand.

I think you need to also ask "What's in the middle?". These would appear to be dual-coil pickups, with a slightly taller profile, and three leads. P90s have a pair of bar magnets coupled at the keeper in the middle of the pickup, with the same pole facing outward. No reason why one couldn't have a six-pak of small rare-earth mags of opposite orientation meet in the middle, such that each coil has its own set of polepieces.

[Mark Hammer]

Well, here's the patent document. I'll let you folks figure it out. Bill Lawrence: Patent

[Mike Sulzer]

Yes, the drawings and explanation show that the pole pieces pass through both coils and are magnetized from the side similar to a P-90 by inward pointing magnets with the same polarity "in" on both sides. The additional feature is that the magnets do not directly touch the pole pieces, but rather attach to the outside of high permeability bars that contact the pole pieces. The purpose of these bars is to provide isolation between the coils. Flux from the vibrating string passing down through the top coil is diverted outward and back up around rather than going through the bottom coil, at least to some extent. A very nice, clean, simple idea and design. Some BS in the patent, of course, they all have it. Why SMC rather than less expensive stronger neo? What's in a fancy sounding name? Neo would work great.

Well, here's the patent document. I'll let you folks figure it out. Bill Lawrence: Patent

[big_teee]

Looks like magnets on the bottom, would make it a lot easier.

[Mark Hammer]

The Bill Lawrence site (or a document I found just prior to finding the patent document, and I can't seem to relocate at the moment) actually discusses why SC instead of Neo, and there seem to be some fairly pragmatic reasons underlying the choice. I think rust was one of them.