Mythbusters Vintage Magnet Wire.

[Spence]

There's a lot of vintage wire smuggling going on here in the UK.
This is a photo of a few of the wire smuggling Mafioso checking out some gear:
Beware, the crusty old geezer is the Godfather of the family and takes no prisoners!

[the great waldo]

There's a lot of vintage wire smuggling going on here in the UK.
This is a photo of a few of the wire smuggling Mafioso checking out some gear:
Beware, the crusty old geezer is the Godfather of the family and takes no prisoners!
[ATTACH]8657[/ATTACH]

Definitely a resemblance to Ronnie Biggs, there are´nt a couple of mail bags under the table by any chance ?

Cheers
Andrew

[Possum]

....

Shifty looking lot, I bet bags of drugs and machine guns are under the table...

I think the Korean connection idea is worth pursuing, I can't afford that on my own for sure. The spools I have don't have a maker's name on them unfortunately, but if anyone is interested I could do some research and take that a step further.

[Spence]

Shifty looking lot, I bet bags of drugs and machine guns are under the table...

I think the Korean connection idea is worth pursuing, I can't afford that on my own for sure. The spools I have don't have a maker's name on them unfortunately, but if anyone is interested I could do some research and take that a step further.

Jonson can put you in touch with the Jopok over there.

[Billy Bones]

I have been having pups made for me in Korea. I got the winder to source pe for them. They sound really right. Its cool to hear that the Korean pe may have a thinner coat. No idea what the copper mix or process is like though. I don't even know who is making it.

[Possum]

....

Well since you have an "in" over there why not find out?

[JGundry]

I don't know if this is enough to account for any coating difference, but I would assume there is some dry down factor with plain enamel wire. The Benzene is probably intended to evaporate out to cure the enamel coating. Do you suppose that the older wire has simply fumed out more over time so the coating is thinner? If this is the case then having a batch done with a thinner coating will not be the same 50 years from now.

[voodoochild]

I don't know if this is enough to account for any coating difference, but I would assume there is some dry down factor with plain enamel wire. The Benzene is probably intended to evaporate out to cure the enamel coating. Do you suppose that the older wire has simply fumed out more over time so the coating is thinner? If this is the case then having a batch done with a thinner coating will not be the same 50 years from now.

That makes good common sense. It does smell when new so like lacquer it should continue to shrink as the solvent evaporates.

[Billy Bones]

I'll see what I can find out. I'm slow at this stuff though!

Billy

[Possum]

.....

Well its possible, but heck, a new pickup six months later sounds totally different anyway. Some of the samples I sent were previously encased in wax. The solvents are there simply to liquify whatever gook they were using, the wire is heated to dry it, so that theory is dubious. Coating methods were totally different than now. I don't think having thinner insulation wire made is going to equal everything else that was different too, like less pure copper and less annealing. I actually have some wire that is single formvar with a very thin insulation and it gets rather dull over a certain amount of turns. But then it is formvar too, not PE.

[JGundry]

I just though of the dry down thing because the dry down for something like Nitro is considerable over time. It might make sense for magnet wire. I think PE would be an evaporative finish. Since we are talking about very tiny differences in coating the difference could be a combination of dry down and and reduction of coating with felt tensioners.

Maybe the annealing difference is work hardening from winding also?

[Possum]

...

If the dry down thing was true then you wouldn't see vintage coils that are still tight probably. No, the annealing diff is from the way it was made, winding does work harden it some, but he told me before even seeing the samples that they didn't anneal the same and the copper wasn't as pure either...

[JGundry]

Could be, but lets say a little a tiny bit of coating is removed from felt tensioning before it ever gets on the coil and then over the years you get tiny bit more from dry down you might still have a very tight coil. If there is such a thing as butyrate bobbin shrinkage that does not seem to leave loose coils.

[Possum]

...

I think buty may shrink as I have seen coils real loose at the start and tight on the outside. I'll dig out whats left of my Korean wire and take another look at that stuff. Everything I wound with it sounded really good back then. The very last of the nom-min REA PE was real strange and was among the test stuff, had about 10 pts coating and real difficult in buckers, with too much brightness...

[JGundry]

I thought I would resurrect this thread after some revealing testing I did the last few days that I think pretty much busts the myth of vintage magnet wire being higher resistance than modern wire relative to O.D. from Copper impurities.

Today I decided to do some ohms per foot testing of AWC and REA magnet wire I have stock piled over the years. I also unwound a 61'or 60' P.A.F., a 52' P-90 Soap Bar out of my 52' LP, and a 56' P-90 soap bar out of my 56' LP. In short I was easily able to find modern wire matches in resistance per foot and outside diameter to all three vintage wire samples. It was quickly apparent that the ohms per foot labels on the REA wire were off. I did all of these readings today under controlled temperature. There are only 3 samples but they cover pretty much the entire vintage PE wire era. All of the pickups were unmolested prior to me getting my hands on them. Below are the results.

52' LP soap bar P-90.
Wire O.D. .00255
Wire res./ft. 1.85ohm
AWC wire equivalent .00255 O.D. and 1.88ohm per foot.

56' LP soap bar P-90
Wire O.D. .0027
Wire res./ft. 1.74ohm
AWC wire equivalent .0027-.00275 and 1.74ohm per foot.

61' P.A.F.
Wire O.D. .00265
Wire res./ft. 1.84ohm
REA wire equivalent .0027 and 1.85 per foot. I'm pretty sure I could find a closer match with a bit more searching of my wire stock.

Basically I don't see any evidence from the readings I got to back up the resistance problem that Possum claims of the modern wire.

I revisited this because as part of my P-90 tests the last few days I realized that the higher resistance REA wire was giving the test pickups lower inductance and higher capacitance than the readings I was getting from the vintage 56' soap bar I was copying. I decided to unwind 10 feet of magnet wire off the 56' soap bar to confirm what was up. Sure enough the vintage wire is way lower resistance than what I was using. I easily found AWC that matched the diameter and ohms reading of the 56' P-90 wire. I loaded the AWC spool on the machine and did a 10,000 turn test that frankly kind of shocked me. The vintage pickup resistance was 7.8K and the 10,000 turn test bobbin came in at 7.88K. With the prior higher resistance wire I was getting 7.85K with 9300 turns. I took 40 turns off the test bobbin and assembled a P-90 with the vintage repro parts I made. Bobbins, baseplates, keeper bar everything made with vintage dimensions and metal specs.. I tool LCR meter readings and the inductance and capacitance were now right on target. In fact LCR readings at 120hz and 1khz for the vintage and test pickups and every parameter of the test pickup was within 1% of the vintage P-90. Most importantly I A/B'd the pickups in my test Gibson R6 and they are indistinguishable in feel and tone. TPL and magnets were the same for vintage and test pickups.

I then decided to take 10 feet off the 52' P-90 and a 61' P.A.F. for an ohms per foot reading and O.D. reading it and see if I had a problem finding modern wire with the same ohms per foot and O.D. for those. No problem at all. I have a bunch of other vintage wire samples I have O.D. reading for but not resistance. I may try and unravel to get a good ohms per foot reading but it won't be fun.

After this I think the evidence is pretty clear that as far as O.D. and resistance goes there is no problem matching modern wire to a vintage wire sample. Now I can't measure coating thickness or Copper purity but I would expect if there were important differences between the two that I would not be able to get a tonal match or get LCR readings that were within 1% of each other for vintage and repro. pickups and bobbins.

Personally I think the resistance per foot varies from batch to batch and always has and the best way to deal with it have a large variety of wire to sort it by O.D. and resistance per foot and to periodically check it though the spool. I have always done sorting by O.D. but have been more lax with the resistance per foot as they correlate to some degree but I think I may change my tune on the resistance sorting.