turns theory.....

[David Schwab]

do you have any of the patent numbers for that? Its an interesting idea, those little strat pickups with tiny coils can be real brigth so doing that would make alot of sense. I'd be interested in knowing exactly how he does it.

5789691 is for a stack, and 5376754 is the closed circuit coil.

He also has 3711619, which uses coaxial coils.

[David Schwab]

I wonder if it's the shorted turns or the gap that he's going for. I think he's into air coils isn't he? I mean several hundred turns would make a nice spacer, sorta.

I haven't seen any air coils from Larwence since his acoustic pickups.

I'd like to see how he does those too.

[Possum]

So, I haven't read the patents yet, but so you would wind a small coil and connect the end of that coil to the start of that small coil, then from the end of that small coil also connected to a new larger coil wound on top of it, is that correct? I"m trying to visualize how this would actually work in real life here. OK I'll go read the patents.

[Possum]

OK, so briefly he is winding another couple layers over his coil and this outer coil is closed and not connected to the primary coil at all? HOw does this work in physics terms? Is it the same as wind a piece of copper foil and connecting the ends over the coil, are are the turns of the outer closed coil killing high frequencies more than one turn of copper foil? Does the outer coil have more induced eddy currents because of more turns of wire than the single layer of copper foil?

[Rosewood]

OK, so briefly he is winding another couple layers over his coil and this outer coil is closed and not connected to the primary coil at all? HOw does this work in physics terms? Is it the same as wind a piece of copper foil and connecting the ends over the coil, are are the turns of the outer closed coil killing high frequencies more than one turn of copper foil? Does the outer coil have more induced eddy currents because of more turns of wire than the single layer of copper foil?

Is the shorted turns grounded? Maybe if we keep talking Bill will jump in and set us straight. I don't understand the shorted turns connected to nothing.

[Possum]

No its connected to nothing. Its a coil wrapped around the inner coil and the ends connected to itself, a closed loop. Maybe Joe Gwinn will tear himself away from his glass of port and turkey sandwich and jump in here. I have one problem pickup this might help out, otherwise its not a real useful trick overall. Useful for small stacked strat type stuff like he does, but then who wants their pickups to sound like Lawrences either.....

[Joe Gwinn]

Is the shorted turns grounded? Maybe if we keep talking Bill will jump in and set us straight. I don't understand the shorted turns connected to nothing.

Consider the Force. Given that a pickup senses the motion of strings through a few millimeters of air, why is a coil connected to nothing any odder?

No visible means of support is required. Nor is grounding, except to reduce electrostatic noise.

No it's connected to nothing. It's a coil wrapped around the inner coil and the ends connected to itself, a closed loop.

Exactly.

Maybe Joe Gwinn will tear himself away from his glass of port and turkey sandwich and jump in here.

Rum. Captain Morgan. Perhaps in eggnog, perhaps not.

[kevinT]

glass of port and turkey sandwich...

hehehe....what a combination

[Possum]

so WHY when overlaying a small coil on top of another one does it only squech the top end when that coil is CLOSED? Current flows in a closed coil? Can't quite figure out whats going on there but it does work....

[Joe Gwinn]

so WHY when overlaying a small coil on top of another one does it only squelch the top end when that coil is CLOSED? Current flows in a closed coil? Can't quite figure out whats going on there but it does work....

The equivalent of eddy currents flows in the closed coil, but cannot flow if the circuit is open.

Put thy faith in The Force, my son.

[Possum]

its still a weird concept eddy currents flowing in a closed coil but not in one with unconnected ends. You'd think there'd still be eddy currents working there because basically you have this mass of copper overlaying the first coil, but NO it has almost no effect when the coil is open. So I guess another way to kill some treble is foil tape and solder it closed, have to try that next. I think SRV did that to his pickups....

[madialex]

its still a weird concept eddy currents flowing in a closed coil but not in one with unconnected ends. You'd think there'd still be eddy currents working there because basically you have this mass of copper overlaying the first coil, but NO it has almost no effect when the coil is open. So I guess another way to kill some treble is foil tape and solder it closed, have to try that next. I think SRV did that to his pickups....

It works, tried it last night on an over bright humbucker using the copper tape, did both coils, 1 wrap each, then used a 1 inch piece on the ends of both and soldered there as well as each coils tape. Took down the highs a very noticeable amount. I think you could infinitely tune PU's this way. Has me thinking now

[Joe Gwinn]

it's still a weird concept eddy currents flowing in a closed coil but not in one with unconnected ends. You'd think there'd still be eddy currents working there because basically you have this mass of copper overlaying the first coil, but NO it has almost no effect when the coil is open.

Well, eddy currents have standards too, and won't flow in any old direction. The rule of thumb is that those eddy currents that can affect a coil flow in a rough image of (parallel to the windings of) that coil. And so currents trying to flow across the width of a foil tape don't get no respect.

[DrStrangelove]

hehehe....what a combination

Yeah, everybody knows you drink a hefty white with turkey
(unless it's during a storm).

-drh