Oil City Pickups: early 60s Strat pickup rewind

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TheGuitarWeaselTheGuitarWeasel Frets: 2732
edited July 2016 in Made in the UK
To some this is the holy grail of Strat pickups, the last flowering of the 'pre CBS' era ... so when it popped onto my bench for a rewind I thought I'd share the story of the rebuild of this this iconic bit of history. It'll be in several parts so please be patient :-)
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The cover is gloriously manky ... just what you'd expect ... but the rust around the poles hints at the reason we are looking at a dead pickup.

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The first thing that strikes me ... aside from the rust ... is the gloriously aged, honey coloured 'Heavy Formvar' wire; by the mid sixties replaced with chocolate brown 'plain enamel' ... and the slightly crazy winding pattern ... indicative of a true hand winding process ... not the machine wind that the mid/late sixties brought.
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Next time stripping and measuring ...
Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
Oil City Pickups  ... The Guitar Weasel blog

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  • TheGuitarWeaselTheGuitarWeasel Frets: 2732
    edited July 2016
    Just before we get to the nitty gritty of getting inside this pickup, a bit of a Fender Strat pickups history to put this particular pickup's importance in perspective:

    The most important changeover in Fender's history was the take over by CBS in 1964, prior to this, with a few minor output changes (and a polarity swap from 'all north up' to 'all south up'), things were pretty much the same as 1954 when the first Strat was made. All the pickups had black fibre flatwork, alnico 5 staggered magnets with small bevels, and were hand wound with 'heavy Formvar' wire.

    The sea change in 1964 was pretty much immediately to swap to PVA coated 'plain enamel' wire, and ditch the hand winding for machine winding.
    Heavy Formvar by the way, is a trade name for a specific 'double build' heavy insulation wire that went out business many years ago ... so if you hear a modern pickup maker describe his wire as 'Heavy Formvar' it is being used as a generic term ... like 'Hoover' to mean vacuum cleaner. It is simply 'heavy build' wire ... every bit as good as the original ... but not actually 'Formvar'.

    The 'deal' with Formvar is the very thick insulation separates the wires out in the coil, this extra room helps break down effects of distributed capacitance (as does the hand winding process),  making a pickup hollow and detailed sounding while still being fat and smooth at the bass end.  
    This pickup is one of the last of the 'early' formula Strat pickups and so very sought after.

    Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
    Oil City Pickups  ... The Guitar Weasel blog

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  • Right ... on with the work! All that Heavy Formvar has to come off!

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    Difficult to see on the picture but there was a fair amount of wax potting apparent on the windings ... but it hadn't soaked all the way to the core, which would have helped to prevent this ...

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    Corrosion on the magnets, spreading down from where sweat and atmospheric moisture has tracked inside the top flatwork. There was no glue used to seal the joint, and no tape used on the pickup core to prevent the inner windings from being attacked by the moisture and acid. When the pickup is rewound tape will be placed in such a way as it doesn't prevent the free flow of wax inside the pickup, but does stop the core wires from touching each bare magnet by a few thousandths of an inch. 
    In common with late fifties/early sixties pickups this will be wound 'right facing, top coming' and south polarity. This is the standard I have adopted for all my own Strat pickups by the way ... except of course RWRP middles.
    Tape insulation fixed, the bobbin is mounted in 'Tweedle Dee' one of my two CNC winding machines, but for this pickup hand scatter winding will be used.

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    The wire is guided by my fingers in the foreground, using a wide scatter pattern and building up the coil to replicate the shape of the original. 

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    Coil wound, and the DCR came out bang on the correct spec for the year. The thick Formvar makes for a very fat coil, and there's very little room for over-winding.
    The hookup wires were very short and so were replaced with period correct cloth covered hookup wire. A difficult job on vintage Fender pickups, as the base flatwork hole it passes through is considerably tighter than on modern pickups.
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    Last job is to lightly relic the hookup wires to help them blend in.

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    And there we go ... back together and ready for another 40+years of playing.
    As is usual with these jobs, the measurements and little quirks I discover in these rewinds will feed back into 'true vintage' replica sets ... so watch this space :-)
    Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
    Oil City Pickups  ... The Guitar Weasel blog

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  • earwighoneyearwighoney Frets: 1291
    Superb. 



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  • These pre-CBS Strat pickups have a smooth and warm character all of their own: a shade more powerful than some later units, they manage to combine a hollow ring with lots of harmonic overtones. Very versatile.
    Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
    Oil City Pickups  ... The Guitar Weasel blog

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  • PVO_DavePVO_Dave Frets: 1159
    Excellent as usual Ash!
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  • TheGuitarWeaselTheGuitarWeasel Frets: 2732
    edited July 2016
    The interesting thing is there is a Strat pickup in Fender's history to suit everyone and pretty much every player and genre ... that's without over-winding and clever switching ... add that, and the Strat becomes an awesome tool.
    Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
    Oil City Pickups  ... The Guitar Weasel blog

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  • ElectroDanElectroDan Frets: 546
    Cool thread.
    How did you get the broken wraps off? Other than CAREFULLY!
    Thanks for posting it.
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  • TheGuitarWeaselTheGuitarWeasel Frets: 2732
    edited July 2016
    As the wire was gone at the core I used a narrow bladed craft knife to sever the bulk of it ... tough to photograph yourself doing ... plus a tiny pair of very sharp nail scissors that I keep just for that purpose, to get the remaining wire.
    Were I unwrapping a machine wound pickup, or one I didn't know the turn count/DCR/ wire gauge for, I would have unwrapped a few layers by hand to measure the wire diameter and calculate the turns per layer.
    Professional pickup winder, horse-testpilot and recovering Chocolate Hobnob addict.
    Oil City Pickups  ... The Guitar Weasel blog

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