Pickup Windings

[Rog]

This from Bill Lawrence - pickup maker

Scattered vs Layered

"Scatter-wound" is just another sales slogan like "aged magnets". A more accurate term would be "random-wound," and any multi-layer winding of wire, finer than 38 AWG, is more or less random-wound. Electricity doesn't distinguish between layered and random-wound coils -- what matters is the count of turns-per-square and the relation between the length and cross-section of a coil.

Tensioning

Even the most advanced coil winders need modification to wind elongated pickup bobbins. Oblong bobbins pull different lengths of wire during the phases of each rotation. This requires synchronized changes in tension during each rotation to avoid pressure points at the narrow ends of the bobbin. These pressure points can cause shorts in the coil which create eddy currents.

Hand vs Machine

Do you really believe someone hand-guides 8000 turns of copper wire that is as thin as a human hair on a bobbin to complete, maybe, 30 coils per day and can guaranty any consistency? A well-wound coil is a well-wound coil regardless if it's wound with professional equipment, or if somebody's great-grandmother winds it to an old French recipe with Napoleon's modified coffee grinder and chops off the wire after a mile with an antique guillotine!

[ash]

Electricity doesn't distinguish between layered and random-wound coils -- what matters is the count of turns-per-square and the relation between the length and cross-section of a coil.

Which is exactly what random winding does. It lowers the count of turns-per-square! Random winding also increases the resistance for a given count without altering other parameters. Does Bill have a better way of doing that with layered coils? Bet he's not telling what it is

Do you really believe someone hand-guides 8000 turns of copper wire that is as thin as a human hair on a bobbin to complete, maybe, 30 coils per day and can guaranty any consistency? A well-wound coil is a well-wound coil regardless if it's wound with professional equipment, or if somebody's great-grandmother winds it to an old French recipe with Napoleon's modified coffee grinder and chops off the wire after a mile with an antique guillotine!

Just like Gibson will have you believe that they have millions of dollars of machinery pumping out 80 LPs a day, but the necks are installed by one guy with a chisel. Or the PRSs are "mostly handmade" to quote their DVD, where moments later you see a CNC router carve out a body in a few minutes. There's nothing wrong with CNC manufacturing, there's nothing flash about handmade anything, but if the market kepps getting sucked in by it, they'll all still claim it regardless of the associated truth and lies.

[scottpalmy]

Look at the Rolls Royce Merlin.

Rolls Royce "Hand made" these engines during the war for Spitfires, Hurricanes, et al.

Packard also manufactured the same engine (for P51 Mustangs) on a Production Line.

The Parkard version was cheaper, manufactured to tighter tolerances, and didn't burn / leak oil like the RR version.

Hand made does not necessarily mean superior.

[Rog]

From a purely physical fit aspect, it seems to me that layering the windings in a tight fit OOOOOO with the next layer above and below it also OOOOOO, fitting in the small gaps above & below the Os, would provide the most copper per cross-section, thus the most copper in the flux path, thus, by e-Blv, the greatest emf and thus signal strength to the output.

But that may be too simple....

[ash]

Yes, thats right, Rog. The trick is though, that maximum efficiency orientations like that (in all kinds of applications) are often the ones with the narrowest band and highest peak. The most finely tuned, you might say. I suspect this gives a pickup with output being strong in its resonant region, but lacking in the higher harmonics. So, focussed but not able to reproduce the high order harmonics that give warmth and depth to the sound...

Don't quote me on that, I was just thinking out loud there, but it seems to fit in with alot of the saled pitches of the name brands. Even that is probably grossly simple compared to the real reason!!

[Rog]

I know when I wound pups I tried to layer them, but after a short time they went on more 'sort of' layered - its a tiring, boring job.