Need help with Teisco Gold Foils

[Steven Wheeler]

Good day everyone,

I need assitance with some pickups and was pointed in this direction as the best resource for help.

I've got a pair of gold foils that I over paid for (shocking isn't it, darn you ebay) that are in need of a major overhaul. The guitar they were in was greatly abused and these showed up at my door full of rust. The covers are fair but I'll not be using them. The coils are intact however the paper wrapper is destroyed. The magnets are in about 100 pieces. The cores were rusty but I was able to save them and was also able to remove the pole screws.The base plates are junk and won't be reused.

Where I'm at now. I'm using one of these on a build. I made a new bobbin out of some heavy paper and slipped it inside the coil and then wrapped the coil with some heavy tape. Not the best situation but it seems to work. I placed the wrapped coil on the core and soldered it up with some new leads. Then I constructed a wooden cover and installed some new longer pole screws. Here's a couple of pictures of the pickups current condition.



Now for the help. Firstly, I need magnets. These were 1/4" x 1/4" x 2 1/4" ceramic magnets. I found a source that I have not been in contact with as of yet. They have 1/4" x 1/4" x3" ceramic 5 and the same in alnico 5. Would either of these be a good fit material wise and would one be better than the other?

Secondly, the coil is wound ccw. This is going in a Tele with a standard bridge pickup. Should I flip the coil to be wound clockwise? Should I install the magnets north up or south up?

Thank you very much for any assistance you can offer.

Steve

[Peter Naglitsch]

I would use the slightly longer ceramic magnets without a thought. That’s what’s available and it will hopefully fit and it will for sure work. If you are doing a vintage restoration I would try to find a way to cut the magnet shorter, but in this project, no. Wounderful wooden cover BTW

Coil winding direction is something that is a bit misunderstood. What should be considered is what Jason Lollar call "path to ground". That means if you have a CW pickup not canceling hum together with another pickup you can simply swap the leads and it will be hum cancelling. Flipping the coil will not change anything. Now all this only applies if the magnetic polarities are dis-similar between the pickups. So you need to make sure that this pickup have south up if you tele pickup is north up and vice verse.

[Mike Sulzer]

Flipping the coil will not change anything .

Possible confusion here. Flipping the coil over changes the polarity of the signal if the if the magnet is not changed at the same time. That is, if you would flip a Fender single coil over and try to use it upside down, there woud be no net effect on the signal polarity since both coil and magnets flipped. If you flip over a humbucker coil, leaving the magnet as is, the polarity of the signal from that coil changes . But it is a lot easier to change the leads. (The two ways of changing the coil polarity are not quite the same because the capacitance to ground is a bit different, but that is a very small difference.)

[Steven Wheeler]

Thank you for the replies Peter and Mike,

I hadn't thouht about just switching the wires. That makes things easy. I'll have to trim the magnets to fit in the new cover. I understand cutting the ceramic magnet can be accomplished with a diamond blade on a right angle grinder, both of which I have. Thanks for the compliments on the cover. It's been replaced with one that has the grain running with the guitar body and the e pole piece hole in the correct position.

Steve

[David King]

I don't know what the original pole screws were made from in terms of alloy but your new black cap screws are likely to be a mid to high carbon steel (grade 5 or grade 8 hardness) and the tone may benefit from them being annealed first. Also a newer magnet is likely to be ceramic 8 instead of ceramic 2 or C5 which could have been in there originally.

[Steven Wheeler]

That is interesting David. I didn't know the grade of steel in the pole pieces could have an effect. The magnets I'm looking at are listed as grade 5. The supplier has a minimum order and as I don't need 100 of these I think I'll be getting some alnico rods and Neo blocks. It appears that I may have stumbled upon a long slippery slope to my next stage in guitar building.

Steve

[Sweetfinger]

I don't know what the original pole screws were made from in terms of alloy but your new black cap screws are likely to be a mid to high carbon steel (grade 5 or grade 8 hardness) and the tone may benefit from them being annealed first. Also a newer magnet is likely to be ceramic 8 instead of ceramic 2 or C5 which could have been in there originally.

Having torn apart/fixed/rebuilt a ton of those over the years, whatever they used, it was cheap! Those old Japanese pickups more often than not have really weak ceramic magnets that are nothing like what you would find today. I reassembled a humbucker using the magnet from one of those older foils and it has almost no pull at the poles whatsoever resulting in a guitar that sustains for quite a long time. Another reason those old pickups sound cool is that they are fairly microphonic- lots of loosely fitting keepers, polepieces, and magnets that can slide around.

[David Schwab]

The magnets I'm looking at are listed as grade 5. The supplier has a minimum order and as I don't need 100 of these I think I'll be getting some alnico rods and Neo blocks. It appears that I may have stumbled upon a long slippery slope to my next stage in guitar building.

You can get some fairly weak ceramic magnets at RadioShack that would probably do the trick. If you switch to alnico or neo it won't sound like a gold foil, but would still sound good.

[Steven Wheeler]

Hi David,
I'll be getting the c5's, I'll be adding the other stuff to meet the minum order $$.

Sweetfinger is right, these pickups are cheap and loose. Kind of reminds me of a... (better stop there)
The magnets, what's left of them, are really weak. I didn't know if that was from age or design. I've read of de gaussing alnico's. Is that a possibility with the ceramics or should I quit while I'm ahead?

Steve

[David Schwab]

I've read of de gaussing alnico's. Is that a possibility with the ceramics or should I quit while I'm ahead?

I've recharged weak ceramics with neo magnets.

[Sweetfinger]

Sweetfinger is right, these pickups are cheap and loose. Kind of reminds me of a...

... A Good time!

I've recharged those weak ceramics as well. Dunno about degaussing a modern one. According to data sheets ceramics will croak under moderate heat- less than Alnico.

[David Schwab]

According to data sheets ceramics will croak under moderate heat- less than Alnico.

Yes, and neos are even lower. But can you remagnetize them again after they hit the curie point?

[Sweetfinger]

You mean REmagnetize them? Dunno what happens to a ceramic after it's roasted to a golden black. How much torque was the Discovery designed to take? Nobody knows. Don't let that stop you from blasting out of Jupiter's orbit.

[David Schwab]

You mean REmagnetize them? Dunno what happens to a ceramic after it's roasted to a golden black. How much torque was the Discovery designed to take? Nobody knows. Don't let that stop you from blasting out of Jupiter's orbit.

Yeah.. REmagnatize.

I know with neos once you have heated them too much they are history.

The curie point of ceramics is 860°F. Alnico is 1470°F. Both are pretty damn high.

[Joe Gwinn]

I know with neos once you have heated them too much they are history.

The curie point of neos is very low, like 140 C. You can remagnetize them after they cool, if you have the right equipment. This equipment isn't common or cheap. It takes a lot more field than alnico.