PAF Pickup Secrets: Resistance, Why does it vary?

In this video Jon Gundry of ThroBak Electronics explains why vintage PAF pickups vary in their resistance reading. The video includes the unboxing of a vintage 1959 ohmmeter. www.throbak.com/paf-pickups.html
Vintage PAF pickups vary in resistance readings due to several factors.
The first of these details is the meter used for measuring resistance used by Gibson in the 1950's. The use of the Allen Electric Equipment ohmmeter meant that assembled pickup resistance readings were limited in accuracy by a .5k resolution ohmmeter scale.
Magnet wire in the 1950's was also subject to 14% variation in outside diameter and ohms per foot within the 42AWG tolerance. Modern min./nom. wire reduces this potential variation to 7%. This makes vintage PAF pickups prone to a wider variation in resistance.
Pickups wound at the Gibson Kalamazoo factory in the 1950's were also wound in a building with temperature variations that affected the consistency and accuracy of ohmmeter measurements of pickup coils. This led to inconsistency in assembled pickups resistance readings since coil readings go up and down with temperature variations.
Because of the use of pickup winding machines both with and without autostop counters, vintage PAF pickups vary in turn count for each coil. This contributes to variation in resistance readings as well.
Finally, variation in turns per layer between pickup winding machines at Gibson in the 1950's further increases the possible variation of pickup coils resistance readings.
www.throbak.com/

[@mikebledsoe2315]

*Jon you have a prodigious amount of knowledge about PAF pickups and pickup manufacturing in general. That's why I'm ordering a set of KZ115's from ThroBak when the stimulus checks are cut.*

[@myvintagesunburst7418]

I've greatfully found the next level of guitar geekdom hero .. thank you sir .

[@gib412]

I want one of these ohm meters! Jon, you're a kindred spirit. Thanks for all of the vids that we guitar geeks can savor like fine wine.

[@RsqSqr]

I just love listening to you!

[@jeffreybranco5702]

So cool and interesting. Great stuff.

[@Alex-nl6sy]

Love your stuff!

[@MrTL666]

Jon love all these videos....

[@11calman]

Wow, just loved this

[@JC-11111]

Whoa. Mail in cards still look exactly like that in 2021. That's crazy!

[@dougmaia]

Awesome info! Greetings from Burst Lovers!

[@therealbeel]

Excellent pickup geekery Jon. Love your dedication! thank you. You make me wonder if temperature differences in performance circumstances actually change resistance and therefore the tone of your pickup. I definitely have experienced mushy tone in hot and humid circumstances and crisper tone in cold and dry. Wasn't sure if it was my mind that became crisp or mushy or what :-). But it's interesting to speculate that the actual electronics could indeed be affected.

[@1972bacosta]

Great video

[@andrewthomaskuster]

Thanks for sharing your knowledge! Fun to watch. Question: since the winding machines wound pretty much as the were set up to, and a range of DCR seems to have been acceptable for Gibson, might the Gibson stations have had those ohmmeters just to test for continuity of the pickup coil (check for no wire shorts or breaks) rather than to target a DCR?

[@ThroBakChannel]

There would be much cheaper ways to test continuity than using a heavy duty ohmmeter. So although it is possible it was only used to show continuity, it seems unlikely.

[@LPCustom3]

Are you going to fill out the registration/warranty card and mail it in? Did Gibson have an LCR meter?

[@fongy200]

I expect the calibration of test equipment wasn't taken as seriously as it is today. The compulsory use of Allen equipment at each winding station would have been about the best calibration they would or could muster at the time. Analogue needle registered vu's are hardly the most reliable too. It's no surprise that Lover's PAF's had such a wide range of output readings Great upload, thank you..

[@ResoBridge]

So how accurate is that Allen meter? I'm assuming its calibration must have drifted a lot since it was made. And did it come with any specifications as to its accuracy? There must be something quite satisfying using these old tools to re-create a product in exactly the same way it was first made all those years ago. I would have thought that pickup makers like Gibson in the 50s would have used resistance measurement of the coils as a quick and simple method of checking there was nothing hugely wrong with the wound coils before they assembled them into the finished pickup. A resistance check would tell you very roughly if there were something close to the right number of turns on the bobbin and would show up and open circuit or any massive shorts. Measuring the inductance and self capacitance of the coils would in those days have required much more expensive, slow and cumbersome equipment, just not suited to production line use by semi-skilled workers. I'm assuming finished coils were never graded in any way, so whether you got a pair of coils on each pickup that were matched, or quite widely different in inductance was purely random happen-stance.

[@ThroBakChannel]

You check the calibration when you turn it on by zeroing it out. It’s easy to adjust the zero point if needed to calibrate. The meter seems accurate and stable.

[@thegolfnut812]

Ohm alone watching informative videos during the year of the virus. Question Jon, you take great detail in making your pickups, I have a 2012 LP with 57 Classic pups wound by ps (sticker on the back) in 2012. Being that there are variations in winding, it's difficult to know if a pickup can sound better unless you take the time and trouble to install them into a guitar to hear the difference between the two. What are your thoughts on this? Thanks.

[@ThroBakChannel]

Your '57 Classics have symmetrically wound coils and are heavily wax potted and do not use true plain enamel wire. These and other non vintage details of current production Gibson pickups mean that ThroBak pickups will have more overtones and dynamics than the '57 Classic pickups in your guitar.

[@thegolfnut812]

@@ThroBakChannel Thanks Jon.

[@LPCustom3]

One meter per station Jon? Is that your short term goal..(?) LOL! Great info! Did Gibson have anything resembling an LCR meter? It'd be great to know what their goal was for pickup specs..

[@ThroBakChannel]

I have seen photos of Seth Lover at Gibson with test equipment, I’m sure he had one. Seth Lover said the spec. was to wind them until the bobbin was full and I think that turn count was left up to the operator. Just as an example the KZ-115 winder will not wind a pickup over 7.8k. You just can’t get more wire on the bobbin the way Gibson set the machine up. By contrast the Leesona 102 can easily make a 9k PAF.

[@LPCustom3]

ThroBak Guitar Lounge Thanks Jon! Nice to know being the geek I am..lol.

[@gib412]

@@ThroBakChannel I did not know this about the KZ-115; Hmm...

[@TheChadPad]

You are a great man. Have you and SDPickups compared notes? If not, I think you should

[@ThroBakChannel]

I can’t think of any reason to compare notes with Dave.

[@TheChadPad]

ThroBak Guitar Lounge I thought it would be like 2 experts combing their knowledge and expertise together. Help each others' craft and whatnot. He seems to be an expert on time period correct alloys and materials and you seem to understand the sonic characteristics of the design intimately. I think if both of those were brought together, you'd both benefit greatly. I am probably generalizing too much. Forgive my ignorance, I just got into this world of vintage electronics, but as a guitarist of 12 years, I am very interested in its growth and development

[@ThroBakChannel]

The first alloy lab tests Dave did were a joint project between him and me that we did in 2008. We split the cost and we both provided vintage parts to be tested. That project was enough for me to NEVER work with him again. After that I did further lab testing and research on my own. I have no interest in seeing any of Dave’s notes. I’m quite sure the ThroBak research has outpaced Dave’s in the 10 years since the first tests. I like to share what I know though and I try to put as much info as I can in these videos without giving up all the secrets.

[@TheChadPad]

Fair enough! Thank you for what you do. I'll be following closely, and I hope to be giving you some business one of these days

[@Ludus4H1]

Nice explanations, I wish you're my neighbor Sir

[@underworld3721]

KOOL!

[@somebodyelseuk]

IF they were measuring at the winding stations, they'd be measuring circa 3.5k. Considering PAFs went in to nearly every guitar... well, you're looking at about 3000 coils just for the 'Burst period' LPs which weren't evem big sellers. I'd think it's more likely they'd calibrate the wire and then maybe check a random coil, rather than testing every pickup.

[@Mark70609]

I prefer the new multimeters, more functions and the input resistance is higher than the old meters, the LCD display is better than the needle, the new meters are more robust too. Those meters couldn't be built with carbon comp resistors as the values would vary and the meter wouldn't be accurate, they must be using wire wound resistors I imagine.

[@ThroBakChannel]

This meter actually very robust. The meter does need to be zeroed out before each use to make sure it is calibrated.

[@Mark70609]

ThroBak Guitar Lounge I forgot about having to zero the ohms function, I bought a Fluke meter and never looked back. What people forget about these old meters is that the best vintage meter for taking voltage measurement was a VTVM (vacuum tube volt meter), the FET input on the new meters gave this performance. Sorry about the rave, some vintage equipment is great other things aren't great.

[@chipsterb4946]

Mark70609 - actually there are times when an analog needle is much more informative than that LED display. A good example is monitoring the B+ on a new amp build, both at startup and after it would have settled down. I love my DMM but also have a FET based multimeter.

[@PurposefulPorpoise]

U measure the entire wire. Wut. Did I hear that right? wow

[@ThroBakChannel]

I measure 10 feet of wire to calculate the ohms per foot.