Is there a way to ID a pickup magnet?

Roxy13

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I've been wondering this for some time based on 2 sets of pickups I have that I can't 100% confirm the model of. What would a guass meter tell me about them? Is there any other way?

Yesterday I dissected this pickup from a 1982 Greco. I've learned this much: it is in fact a Maxon from 1982 on production line 8. The neck reads 7.56k ohm and the bridge reads 7.93k ohm. The guitar is very likely an EGC 500 so the pickups should be ceramic magnet U-1000 or UD, but to me they look more like AlNiCo magnets. The bottom of the magnet is shinier than the top although the pickups are lightly wax potted and those black areas might be wax and dirt. I tried to test for continuity in 2 or 3 places and got an open/infinite circuit so maybe they really are ceramic.

I'll post a photo I took of it as well, but still going back to my original question: is there a sure fire way to ID magnets? The other pair I want to ID either has AlNiCo 3 or 5. None of the magnets are stamped or color coded.

IMG_20200103_161609791.jpg
 

LtKojak

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Your initial assumption is correct: ceramic magnets don't produce continuity when poked with a Multimeter. Alnico ones do.
 

Roxy13

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Your initial assumption is correct: ceramic magnets don't produce continuity when poked with a Multimeter. Alnico ones do.
Does the wax potting interfere at all with trying to check the continuity?
 

Roxy13

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If you do it right, no.
What do you suggest since I've never done it before yesterday? I set my multimeter to continuity and crossed the leads to check it. It showed near 0 and beeped at me. But when I touched both probes to the magnet in a couple/three places it read open.
 

cooljuk

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If you send them to someone with the proper tools, they can be identified to a good degree of certainty, non-destructively, and returned to their as-received charge levels after.

Ceramic is plastic and AlNiCo is mostly iron. You should be able to tell the difference by weight, just between those two.

Really, between AlNiCo 3, 5, and ceramic, the differences should be pretty obvious to your ears, when you install them all in the same pickup, one after the other. ....presuming they are all fully charged and you have a reasonably clear pickup, at least.
 

RAG7890

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When I have the spare time, I'm going to measure the 1950's Vintage Mags I own.............although I might leave it just the 3 x Sets I have that are unused vs. pulling them out of Vintage PU's.

This is what I'd use XRF.................completely non destructive testing & perfect for Alnico Magnets: -



James are you in?

Cheers, Rudi
 

cooljuk

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When I have the spare time, I'm going to measure the 1950's Vintage Mags I own.............although I might leave it just the 3 x Sets I have that are unused vs. pulling them out of Vintage PU's.

This is what I'd use XRF.................completely non destructive testing & perfect for Alnico Magnets: -



James are you in?

Cheers, Rudi
They make a little handheld version of those, used in the construction industry. Some building codes or laws, apparently, require individual materials testing of every load bearing structure's steel. Right now, they are $10k+ meters, but they have already come down in price to less than half of what they first were. I'd love to have one, when they get a bit more reasonable. ....or at least a friend with one. ;)
 

Roxy13

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Well, the ones I think have A3s don't sound quite the same as the Dry Zs that have A3s, but they are a later version of Dry 82s, made after they ran out of certain parts like the 50s wire I guess.

I'll compare the weight of the above magnets with other alnico ones I have here I guess and see what I can tell from that. If those are lighter I'll chalk them up to being ceramic.

@RAG7890 I think that is a little out of my potential spending for a set of pickups that probably have little value, lol!
 

cooljuk

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To use your ears, you would have to compare the magnets all in the same pickup/height/setup/strings/rig/settings/etc. back-to-back. Using different pickups will give you unclear results.
 

cooljuk

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If you want to drop the magnets in the mail to me, I'll hook you up. Just cover the return shipping.
 

Roxy13

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If you want to drop the magnets in the mail to me, I'll hook you up. Just cover the return shipping.
I may have to take you up on that! Could both that "ceramic" one and the probable A3 go in the same box together?

I figured you had to use the magnets in the same pickup and same guitar to really decide what suits it all best.

I did the comparison with the supposed Dry 82s to the Dry Zs just because they are supposedly pretty close pickups, but I'm not certain those really are Dry 82s, and even if they are they are a later version of them after original parts ran out.

So my curiosity can go to extreme lengths maybe wanting to know for certain what both of these sets of pickups really are.

I have even considered getting some more magnets and comparing those with the magnets in it. Like putting a known A3 into a pickup I think has the A3 and seeing how close they are, and then trying some others in it to see how close/different they are. I have some of your short A2s, James, that came extra with one set of your pickups I've bought used, but no extra A3, A4 or A5 without pulling them out of extra pickups here.
 

cooljuk

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You can ship them together. Just keep them separated by a few inches. If you email me, I'll reply with my address and a form to include.
 

Mick51

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Or, you could just use the "refrigerator door" method to determine the relative strength of each magnet. Slap them each on the side of a refrigerator, and see how much force is required to pull them back off. If they're each anything like normal charge, that should give you some sense of relative strength.
 


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