Real NOS PAF era plain enamel wire....

[JGundry]

I would think you'd need to measure a good long section, more than a foot then average it out since just a one foot piece is unlikely to match same from other parts of the roll. The actual insulation measurement can make your ohms measurement meaningless if its different from your other stock, so your wire could sound real bright or dark but have close ohm specs.

Possum it sounds to me like you have not really given much attention to experimenting with reading ohm per foot for yourself in a controlled way. You really should. First wrap 10' of magnet wire around a foot long ruler, make sure you are always in the same ambient temperature, take your reading, divide by 10, done. Easily done for all of your wire new or old and more reliable relative to the readings on a spool if there. Taken with an inductance reading of a control test coil you can extrapolate coating thickness relative to ohms per foot if you want. As far as reading wire from a wound coil or off a spool, from my tests if you keep the tension around 20 grams you don't get any difference in ohm per foot after winding. Maybe a .01 ohm added at 25 grams. IMHO Gibson vintage stuff was wound below 25 grams sometimes well below 25 grams of tension.

[Possum]

No, I haven't because I have Elektrisola's specs on every kind of wire thats been made since 2002 among the modern PE offerings, including what MWS sells now, Essex, REA, Korean PE, a few others. Plus every vintage sample of PE I collected over ten years, multiple PAF examples, P90's, a Nocaster, 50's steel guitar from Fender, P13's, minibuckers, CC pickup, CBS Strat etc. etc. So all the wire I currently have new and old I have lab specs on. I just plain don't use it in practice, it was highly educational to see that up until 1965 PE was different then it changed more to what we buy now. I mic every new roll to make sure nothing changed and I QC all my pickups so if there's a sudden change in final reading I know something is wrong or the wire changed. But since Elektrisola makes PE now there have been no variations in wire I buy. When REA was making wire it changed every six months and screwed me up many times. I don't know exactly how Elektrisola's lab reads ohms per foot but they were able to do it on cut off coils with not much length at all. I've only done a measurement once and ran out about 20 feet of new and vintage wire and even then there was a difference, but I realized its just too hard to control a consistent temperature in a home environment so didn't pay alot of attention to it. Just the fact that you're breathing near it or have a light on near your work would invalidate things if you want to get picky. My own work table lights always heat the coils up enough that the readings change from winder to work station. All my pickup recipes are turns counts and I know each one by heart and know which wire to use. Ohms per foot was just a research tool, just like insulation thickness and bare wire sizes of vintage wire were, but in day to day production I don't use it at all.

[JGundry]

Possum, ohms per foot is one of your best QC and research tools when it comes to magnet wire. Having your own in house standard for testing it is worth the effort IMHO. Test everything old and new and mic it as well is my advice.

[Possum]

Elektrisola never varies, and since I use turn counts I know what the DCR of the finished product should be, no need for anything further than that. Its the same thing anyway, 5000 winds in a recipe equals a certain DCR in known wire, if it starts coming out noticeably different then something went wrong in the coil. I know Wolfe is really into ohms per foot last I heard but then that was in REA days when it would of been helpful. I kind of don't see the point anyway since I'm not winding to "ohms." I don't need it and its all on lab printouts anyway if I ever did. Even then if we were getting variations in wire or had other companies making it my bottom line is my turn count because that determines what your actual voltage output is, so if there was other wire available all I would do is wind it to the same turn count and see how it sounds, mic it, and read the total DCR. I really don't need anything else. With the NOS 50's roll of wire, thats exactly what I'll be doing, I already mic'd it, so will wind to a recipe and see what DCR it comes out and probably check the peak rez too and a frequency analysis vs. an identical coil in modern wire. I'm kinda swamped with projects so its going to be awhile before I wind that wire, there's not much of it so need to have some space to test it out.

[JGundry]

Possum, it sounds like you have it all figured for yourself. But I think you are missing the bigger picture. Say you own a pickup you like, you unwind 10 feet of magnet wire from it and take an ohms per foot reading, find duplicate diameter and ohms per foot wire, do a test coil then calculate your turn count. Confirm with an inductance reading. That is great starting point if you are working on cloning a pickup. Call it turn count, call it ohms.... if you can control the temperature you can get and apply extremely useful data with ohms per foot and mic readings. Applying the data just means having a good variety of wire on hand and having a temp. controlled environment.

[Possum]

Its rather pointless though, because we are stuck with the wire that is being made NOW, the fact is that the most common diameter I found in 99% of PAF's I unwound isn't being made currently. They will make it custom for you if you want to buy 100 pounds of wire, but really it wouldn't be a huge difference anyway. So that choice isn't available, though yeah I do have some old stock thats in the that diameter I don't use it because there's not enough of it to consistently make the same recipe for the next five years, and I tend to save it for important rewinds. Besides the PAF tone simply isn't in one single part of the pickup, the coils are important but they are only one piece of the whole. I'm very happy with the wire we're getting, its consistent and I can rely on it not to make some dramatic change like REA's stuff did. I've really got everything nailed down in every part of the pickup and making it all do exactly what I want it to. There is one odd thing about Elektrisola's wire is that their measurements are very conservative and I sometimes wonder if their laser is a bit off the mark, because historically all the other wire that was being made wasn't what they tend to make as far as common diameter goes. It'll be interesting to see finally what this old 50's wire sounds like, I'll post when I get to it in probably a month or so....

[Joe Gwinn]

There is no reason one cannot measure ohms per foot accurately (1% or 0.1%) at home, using only a digital multimeter (that has a 50 ohm range), a ruler, and a thermometer.

[big_teee]

There is no reason one cannot measure ohms per foot accurately (1% or 0.1%) at home, using only a digital multimeter (that has a 50 ohm range), a ruler, and a thermometer.

I never did understand the argument against measuring.
It makes logical sense to me if the wire is a given OD and a Given ohms per 10 ft at a given Temp?
WTF? You have to be in the Ball Park?
I measure everything that comes through here, and every roll is a bit different, some a lot different.
T

[Fuzzy Logic]

I just scored a 5lb. roll of PE from 1971 for $16, its 40 gauge. Very modern stuff. You have to be careful about this ohms per foot stuff. The data I got from Elektrisola was done in a lab, I'm not real sure you can get accurate measurements at home, I'm sure they have some kind of temperature controlled device and a high tech meter of some sort. The REA stuff always had ohms per foot written on each roll usually. I would think you'd need to measure a good long section, more than a foot then average it out since just a one foot piece is unlikely to match same from other parts of the roll. The actual insulation measurement can make your ohms measurement meaningless if its different from your other stock, so your wire could sound real bright or dark but have close ohm specs. Then there's bare wire spec which also varies, you have to acid strip the insulation or your measurement will be wrong. Elektrisola uses lasers to measure their specs and a simple micrometer is just not very accurate overall. I always mic new rolls of wire but in the end only winding coils and listening to a new batch is the final word.

Actually, one does not really have to acid strip the insulation in order to figure out the diameter of the bare copper wire. If one knows the ohms/foot the calculation of the diameter of the bare copper wire is relatively easy.

Ohms/foot = (ohm-circular mil/foot) / (cross section of wire in circular mils)

The standard value for the resistivity (ohm-circular mil/foot) at 20 degrees celsius is: 10.371 ohm-circular mil/foot.

The NBS copper wire tables of 1956 and 1966 indicate that the value of 10.371 would appear to be a correct value to use (unless very high quality wire, in terms of resistivity or conductivity, was used in those days for winding pickups, which I doubt) when assessing "vintage wire" as used in the fifties and sixties. According to the specifications as found on their website, this is also the correct value to use for assessing modern MWS wire.

The cross section of a bare copper wire in circular mils is the square of (diameter wire / 0.001).

From the above follows:

diameter bare copper wire = 0.001 x square root (10.371 / (ohm/foot))

And if one is able to measure the outer diameter of the insulated copper wire with sufficient precision, the insulation thickness is the difference between this measured value and the diameter of the bare wire as calculated above divided by two.

Since you have done a lot of lab testing, I guess it would be quite easy for you to verify the claims as made above.

BTW: for the most accurate results the standard value of 10.371 should be adjusted to 10.328 for modern Elektrisola wire (0.0024 size wire) and to 10.325 for their AWG 42 size wire.

[SonnyW]

Actually, one does not really have to acid strip the insulation in order to figure out the diameter of the bare copper wire. If one knows the ohms/foot the calculation of the diameter of the bare copper wire is relatively easy.

Ohms/foot = (ohm-circular mil/foot) / (cross section of wire in circular mils)

The standard value for the resistivity (ohm-circular mil/foot) at 20 degrees celsius is: 10.371 ohm-circular mil/foot.

The NBS copper wire tables of 1956 and 1966 indicate that the value of 10.371 would appear to be a correct value to use (unless very high quality wire, in terms of resistivity or conductivity, was used in those days for winding pickups, which I doubt) when assessing "vintage wire" as used in the fifties and sixties. According to the specifications as found on their website, this is also the correct value to use for assessing modern MWS wire.

The cross section of a bare copper wire in circular mils is the square of (diameter wire / 0.001).

From the above follows:

diameter bare copper wire = 0.001 x square root (10.371 / (ohm/foot))

And if one is able to measure the outer diameter of the insulated copper wire with sufficient precision, the insulation thickness is the difference between this measured value and the diameter of the bare wire as calculated above divided by two.

Since you have done a lot of lab testing, I guess it would be quite easy for you to verify the claims as made above.

BTW: for the most accurate results the standard value of 10.371 should be adjusted to 10.328 for modern Elektrisola wire (0.0024 size wire) and to 10.325 for their AWG 42 size wire.

This publication from Phelps-Dodge verifies that the 10.371 was the standard in 1961 - see paragraph C page 2.
http://bnordgren.org/seismo/wire.pdf

I believe that 10.371 is also the current International Annealed Copper Standard (IACS) value for 100% conductivity.
Table 1 Equivalent Resistivity Values For Copper
Conductivity at 20°C (68°F), percent IACS...................100.00
VOLUME RESISTIVITY
Ohm-Circular mil/f ..................................................10.371 000
0hm-mm2/meter................................................... ....0.017241

Elektriksola specifies a volume resistivity of 0.0171 ohm-mm2/meter which is lower than the IACS value, so I understand why the value should be corrected for Elektriksola wire, but why the difference between the two gauges?
Copper

Also
Here's a handy chart to correct the resistance
Attachment 19729

This is another useful publication I have used for years:
Technical Data

I measure the temperature at my workstation with an inexpensive but accurate Cole-Parmer digital thermometer, and correct all my published resistances to 20C using the chart from REA, or the equivalent formula which is built into my data worksheet.

[Possum]

Thats all well if you think that published charts are accurate at all ;-) There are standards for bare wire and O.D. for every gauge, but then there are wide range tolerances for those standards. You really can't accurately measure wire diameter with a micrometer anyway, it gets you in the ball park but only a laser is going to give you real accuracy. Bare wire diameter depends on who made it and what stage of wear the drawing dies are in. Then you're not considering if the wire was stretched when it was wound onto the roll, if it was then your charts don't mean anything. From my experience every roll of wire I've bought was stretched at the beginning of the roll due to higher toque from the smaller core diameter pulling on the wire. Some rolls radically change diameter when you get down to the core. Elektrisola's wire is no different and the wire is always fattest on the outside of a new roll of wire. That too, makes it kind of pointless to go around measuring how many ohms a foot of wire measures. Do you measure a piece from the start, middle or end?
If you use turn counts in your recipe, that never changes from pickup to pickup, so you have a very long length of wire thats relatively the same on every pickup and you note how many ohms the whole length is. With current wire, I get very close results every time and if there's a noticeable difference it means a short happened so I wind it over. Thats why I don't bother with ohms per foot, its just not practical for my work. For research, yes I wanted to know exactly what their lab said, because I had PE from about a 50 year spread and many of them were the same total O.D. But among those, insulation thickness varied more with the vintage stuff before '65. They also told me the earlier wire copper was less pure due to technology of the time, so ohms per foot back then was higher than currrent wire, but there's more to that than just copper purity......Unfortunately too, we can't really know what dielectric effects the old recipe for PE was vs. what they use now. We've had that argument before ;-) Currently EPA regulations change how the insulation enamel is made and what its made of, back then didn't matter. Some PAF's I got the wire really smelled good ;-) I even had a PAF where the insulation was never properly cured and it was still sticky all through the entire coil. Elektrisola told me they think the insulation never changed, but then they also told me the guys who make that stuff refuse to talk about the processes at all, uh huh.....

[JGundry]

Possum, everything has a tolerance. A reasonable tolerance for ohms per foot readings, charts etc.. is to be expected. But as far as the tolerance for speculation and assumption that is extremely wide and is not real useful in terms of making pickups.

[Possum]

Ohms per foot has no use for me in making pickups, is my bottom line. Total turns recipe = known resistance in known wire for known product. Thats all I need in a practical day to day situation, why make it more complex? I already know what all the specs for the wire I use, direct from Elektrisola's own lab done on their own wire, plus any other PE you care to mention, new or old, been there done that; it was research, but that work is done. Why spend time measuring lengths of wire when its not going to be the same at the beginning of a new roll as the end of the roll, its going to change as the roll gets used up, so literally you would have to measure every time you wound a new set of pickups ;-) and to what purpose? A turns recipe gives you a DCR thats going to only vary maybe .2K if that, and its the only thing you need to check in final QT. If you suddenly get a jump in the reading, plus or minus, your coil went sour and should be cut off and done over. Those are my methods and what I use day to day, simple, effective and quick. If ohms per foot has some value for you in making pickups then use it, but for me it has no actual production value; I know what my wire is and use what I know. I actually repurpose rolls when they get near the end and when wire gets thinner, and use it for a different purposes. You just have to "roll" with the roll ;-)

[David Schwab]

Ohms per foot has no use for me in making pickups, is my bottom line.

I think the point was to measure the resistance of the wire to determine it's diameter as compared to another sample.

[Fuzzy Logic]

.......
Elektriksola specifies a volume resistivity of 0.0171 ohm-mm2/meter which is lower than the IACS value, so I understand why the value should be corrected for Elektriksola wire, but why the difference between the two gauges?
Copper
.....

In the overview below, the ohms/1000 feet are listed for three manufacturers of magnet wire and for two AWG sizes in the order "Max d", "Nom d" and "Min d" where "d" is the diameter of the wire.

MWS

AWG 42: 1534, 1659, 1801
AWG 42.5: 1659, 1801, 1960

Values are based on a resistivity of 10.371 ohms per circular mil/ft (100% IACS conductivity).
Ref: http://www.mwswire.com/pdf_files/mws...Book082011.pdf

Essex

AWG 42: 1510, 1659, 1801
AWG 42.5: 1633, 1801, 1960

Minimum resistance values are based on maximum bare diameter ("Max d") and 101.6% IACS conductivity.
Nominal and maximum resistance values ("Nom d" and "Min d") are based on nominal bare diameter and 100.0% IACS conductivity.
Ref: http://www.spsx.com/uploadedFiles/Ma...ook_linked.pdf

Elektrisola

AWG 42: 1504, 1652, 1801
AWG 42.5: 1626, 1793, 1960

For "Min d": Resistance based upon copper conductivity of 100% IACS. Actual values for "Min d" may be up to 102% IACS.
Ref: http://www.elektrisola.com/fileadmin...asheet_eng.pdf
Note: Elektrisola specifies they use copper base material with a resistivity of 10.286 ohms per circular mil/ft (volume resistivity of 0.0171 ohm-mm2/meter).

Now what do we have here.

MWS specifies their ohms/1000 feet based on 10.371 ohms per circular mil/ft (100% IACS conductivity) and they do this for the whole range of "Max d" to "Min d" of a given AWG wire size.

Essex notes that they base their ohms/1000 feet value for "Max d" on 101.6% IACS conductivity and that "Nom d" and "Min d" values are based on a IACS value of 100%. So the resistivity is not really a constant value.

Elektrisola notes that they base their ohms/1000 feet value of "Min d" on 100% IACS conductivity but that actual values may be up to 102% IACS. Furthermore, when using the 10.286 ohms per circular mil/ft which they specify for their copper and the ohms/1000 feet listed on their website for AWG 42/42.5, the resulting diameter of the wire is less accurate than expected. From all this it appears that the resistivity of Elektrisola wire is even less constant than in the case of Essex wire. That is why I listed a value for two different wire sizes. The resistivity values I mentioned are based on the AWG size and corresponding ohms/1000 feet which they list on their website.

The only reason (imho) why the resistivity values are not that constant for Elektrisola wire may be that their wire is probably not as fully annealed as compared to the wire which MWS sells. Essex is probably somewhere in between these two.

This appears to be confirmed by the maximum recommended winding tensions for these three manufacturers: 34 gr. for Elektrisola, 27 gr. for Essex and 22 gr. for MWS. The higher the maximum recommended winding tension, the higher the tensile strength of the wire is and this indicates that the tensile strength which has been obtained during the hard drawing of the wire is not as much reduced by the annealing process for Elektrisola wire as in the case of MWS/Essex wire.

Technically the Elektrisola wire is the better wire because it has a high tensile strength combined with an overall better resistivity value. It will probably handle better and also break less. However, at the same time is also a wider spread in the ohms/1000 feet across the range of "Max d" and "Min d" for a given AWG size as compared to MWS/Essex wire. And if one is set to wind to a specific or fixed DCR one will need put a bit more wire on the bobbin when using Elektrisola wire.

All this is based on published specifications of the various manufacturers, in real life your mileage may vary.....

And since we are all sharing links here:

United States (National Bureau of Standards), 1914. Copper Wire Tables, NBS Circular 31
Copper wire tables : United States. National Bureau of Standards : Free Download & Streaming : Internet Archive

United States (National Bureau of Standards), 1966. Copper Wire Tables, NBS Handbook 100
http://library.bldrdoc.gov/docs/nbshb100.pdf

The NBS copper wire tables of 1956 used to be viewable/downloadable in Google books, but that link has disappeared....

[Possum]

Its the "real life" part that only concerns me. You just have to buy from different sources and wind the stuff to really know what it is and what you can use it for.
REA spools used to all have ohms per foot specs written on them for each spool.

I just opened a new roll last night. The outer windings are a whole .0001" thicker than the last roll's inner windings. Doesn't sound like much but makes a big difference in size of coils when you got thousands of turns on the pickup, that small difference adds up fast. I try to burn off the thicker part of the rolls on pickups like Tele bridges etc. to get down to the diameters I need. Everyone's wire is a little different, Wirenetics for example sells Elektrisola product but its like they buy the cast off over-spec spools or something because the diameters on everything they sell it seems are overboard sizes, FAT. But for certain pickups you WANT fat wire, so I go to them.

Fralin used to say that they would wind a test pickup on every new roll of wire they got in, but its not really a great method because of the stretched wire in the core of the roll. But the only way to know any wire isn't by reading specs, you have to work with it and it'll let you know real fast whats its good for and what its not good for.

[SonnyW]

The only reason (imho) why the resistivity values are not that constant for Elektrisola wire may be that their wire is probably not as fully annealed as compared to the wire which MWS sells. Essex is probably somewhere in between these two.

This appears to be confirmed by the maximum recommended winding tensions for these three manufacturers: 34 gr. for Elektrisola, 27 gr. for Essex and 22 gr. for MWS. The higher the maximum recommended winding tension, the higher the tensile strength of the wire is and this indicates that the tensile strength which has been obtained during the hard drawing of the wire is not as much reduced by the annealing process for Elektrisola wire as in the case of MWS/Essex wire.

Technically the Elektrisola wire is the better wire because it has a high tensile strength combined with an overall better resistivity value. It will probably handle better and also break less. However, at the same time is also a wider spread in the ohms/1000 feet across the range of "Max d" and "Min d" for a given AWG size as compared to MWS/Essex wire. And if one is set to wind to a specific or fixed DCR one will need put a bit more wire on the bobbin when using Elektrisola wire.
....

Thanks. I'm not sure, but I think I am a bit less confused now....maybe.

[Possum]

Just remember that stretched wire has higher ohms per foot, so by the time you get to the end of a 6lb. roll, ohms per foot has changed, and so has diameter, and so has work hardening....

[RedHouse]

I never did understand the argument against measuring...

Easy, consider the source! (LOL)

[RedHouse]

Just remember that stretched wire has higher ohms per foot, so by the time you get to the end of a 6lb. roll, ohms per foot has changed, and so has diameter, and so has work hardening....

So what makes you think the "end" of the spool had a differrent stretching/stretched factor than the rest of the spool?.

And BTW when you say "by the time you get to the end of a 6lb. roll" don't you really mean "by the time you get to the start of a 6lb. roll"?
(just wondering)

[Steve Conner]

If the spool was wound with constant torque on the spindle, the inside layers would be tensioned more than the outside.

[RedHouse]

Yes, that's quite true, but they're not wound by torquing the spool but using elaborate tensioning-wire-guide apparatus.

BTW, I love your sig-note, "douchebaggery" what a word!
(and how true it is)

[Fuzzy Logic]

This is Rola enameled wire data from 1954. And, as to save some people the trouble of downloading the attachment, it is not data of "plain" enameled wire and this wire was not made in the USA but in Australia.

Nevertheless, of few things may be of interest.

1. On page 5 it can be observed that the diameter values of the wire gauges 41-44 differ from the "official" or "published" values. AWG 42 is on this page defined as having a diameter of 0.0024" (instead of 0.0025"). On the other hand, on page 11 they use 0.0025" for the AWG 42 wire size of their new wire. There appears to be a transitional thing going on here.

2. The permissable enamel addition is specified on page 5 as being 0.0002" to 0.0004" for AWG 42. Nowadays it is more like 0.0002" to 0.0003".

3. On page 11 the ohms/1000 foot for AWG 42 is specified as being 1673 Ohms (a conductivity which is a little below 100% IACS).

[Fuzzy Logic]

Its the "real life" part that only concerns me. You just have to buy from different sources and wind the stuff to really know what it is and what you can use it for.
REA spools used to all have ohms per foot specs written on them for each spool.

I just opened a new roll last night. The outer windings are a whole .0001" thicker than the last roll's inner windings. Doesn't sound like much but makes a big difference in size of coils when you got thousands of turns on the pickup, that small difference adds up fast. I try to burn off the thicker part of the rolls on pickups like Tele bridges etc. to get down to the diameters I need. Everyone's wire is a little different, Wirenetics for example sells Elektrisola product but its like they buy the cast off over-spec spools or something because the diameters on everything they sell it seems are overboard sizes, FAT. But for certain pickups you WANT fat wire, so I go to them.

Fralin used to say that they would wind a test pickup on every new roll of wire they got in, but its not really a great method because of the stretched wire in the core of the roll. But the only way to know any wire isn't by reading specs, you have to work with it and it'll let you know real fast whats its good for and what its not good for.

But isn't that 0.0001" difference in diameter less than the inherent tolerance for the wire size you buy, provided that the diameters of those two wires are somewhere within the range of 0.0024" - 0.0026" (for AWG 42) ? Even when buying min-nom or nom-max (I have no idea if you can actually buy min-nom or nom-max Elektrisola wire) one should not be offended by a difference of 0.0001" between two spools (or even within the spool).

BTW; I think that coil size differences due to an increase/decrease in wire diameter are more directly related to the number of layers instead of to the total number of turns on a bobbin.

[David Schwab]

But isn't that 0.0001" difference in diameter less than the inherent tolerance for the wire size you buy, provided that the diameters of those two wires are somewhere within the range of 0.0024" - 0.0026" (for AWG 42) ? Even when buying min-nom or nom-max (I have no idea if you can actually buy min-nom or nom-max Elektrisola wire) one should not be offended by a difference of 0.0001" between two spools (or even within the spool).

I use mostly Elektrasola wire, and the label says "min nom" and they write the actual measured diameter for that roll in pencil. So clearly there is a variation in sizes within the min nom tolerance.

I have never heard any difference in tone from one roll to another.

BTW; I think that coil size differences due to an increase/decrease in wire diameter are more directly related to the number of layers instead of to the total number of turns on a bobbin.

Probably. Different size wires sure to give a different tone, as do wire insulation thickness. I'd bet if anyone hears a difference in insulation types it's because of the thickness of the insulation.

[JGundry]

This is Rola enameled wire data from 1954. And, as to save some people the trouble of downloading the attachment, it is not data of "plain" enameled wire and this wire was not made in the USA but in Australia.

Nevertheless, of few things may be of interest.

1. On page 5 it can be observed that the diameter values of the wire gauges 41-44 differ from the "official" or "published" values. AWG 42 is on this page defined as having a diameter of 0.0024" (instead of 0.0025"). On the other hand, on page 11 they use 0.0025" for the AWG 42 wire size of their new wire. There appears to be a transitional thing going on here.

2. The permissable enamel addition is specified on page 5 as being 0.0002" to 0.0004" for AWG 42. Nowadays it is more like 0.0002" to 0.0003".

3. On page 11 the ohms/1000 foot for AWG 42 is specified as being 1673 Ohms (a conductivity which is a little below 100% IACS).

An interesting fact as it relates to overseas magnet wire. When I bought my old Gibson made winder from Heritage Guitar they still had boxes of 44AWG Poly wire from the Gibson days. The wire was made in Italy and it was on what I believe were pressed fiber spools and I would guess they were from the 60's or 70's. Why did Gibson buy 44 AWG wire from Italy? Probably because they could save a buck on it. My point with this is perhaps this explains the smaller diameter wire that is on some hotter 59' era P.A.F.'s. Maybe it was 42 AWG from an overseas wire maker that had a different min. tolerance for 42AWG that a USA wire maker would have. Just a thought.

[Possum]

That .0001" difference blows the coil SIZE up very noticeably when using a standard turns count recipe. If you have limited space it can be a problem.
I've heard various theories about why the PAF wire diameter changed, the dies wore out etc. etc. no one really knows. But we saw the same thing with REA Magnet wire, it went from being very thin to being very thick wire in the space of about 3 years, all from one company. It totally played hell with what I was making at the time.

[WolfeMacleod]

Elektrisola never varies, and since I use turn counts I know what the DCR of the finished product should be, no need for anything further than that. Its the same thing anyway, 5000 winds in a recipe equals a certain DCR in known wire, if it starts coming out noticeably different then something went wrong in the coil. I know Wolfe is really into ohms per foot last I heard but then that was in REA days when it would of been helpful. I kind of don't see the point anyway since I'm not winding to "ohms." .

I still pay attention to Ohms Per Foot, and yes, Elektrisola does vary, and quite a bit. I have a very specific range of wire I will accept, plus or minus about 10ohms per 1000 feet. Anything over that, and I have to add or subtract turns. Ohms + Turns counts = consistency, and I know that if I have "X" turns = "X" ohms at "X" degrees that my tension is also "pretty damn close"

[Possum]

With the varying diameter thru the spool I personally stick with turn count recipes. So pickups from the start of the spool measure a little lower in ohms, and higher at the end of the spool, but its not enough to concern me. I think things like capacitance and the various spooky eddy current things probably remain pretty constant with using turns counts because I don't hear dramatic changes in tone enough to be concerned about. My Elektrisola spools diameter at beginning and end of the spools since they started making PE for MWS has all been very stable in size, am really thankful for that.....