Broken pickups that "work"

[rhgwynn]

The Humbucker From Hell, Nancy's Bridge... they give up no ohm readings, yet still "work"....

So, what's going on here??

-Rob

[mcgruff]

Multimeter not switched on?

[copperheadroads]

The Humbucker From Hell, Nancy's Bridge... they give up no ohm readings, yet still "work"....

So, what's going on here??

-Rob

That humbucker is suppose to be about 5.9k ,I'm not familiar with its design ,but I wonder if it uses a cap between the coils to tame the treble ,If so you would not get a dcr reading

[Leo_Gnardo]

That humbucker is suppose to be about 5.9k ,I'm not familiar with its design ,but I wonder if it uses a cap between the coils to tame the treble ,If so you would not get a dcr reading

It's "open coil" and you're hearing "capacitive pickup", probably trebly and rather weak. Can't ever remember seeing a capacitor interposed between pickup coils on purpose. It would block lows & pass highs anyway if there was one there.

[rhgwynn]

Well we've all come across pickups with a break in the coil, and that didnt work one bit, right?? So what caused those to not work at all, and these to work? And yes, Nancy was a very unique sound and very trebly with little to no bass. Apparently, supposedly, that fellow Don Mare has put a lot of work into replicating it?? Just how the hell to you reliably make a "broken" pickup that works, time and again? I mean, aren't these pickups just freaks of nature? Even his dont give up ohm readings just like the original. I bet if you unwound the Nancy bridge, you'd never get it to work again. Can anyone explain this phenomenon in depth?

-Rob

[copperheadroads]

It's "open coil" and you're hearing "capacitive pickup", probably trebly and rather weak. Can't ever remember seeing a capacitor interposed between pickup coils on purpose. It would block lows & pass highs anyway if there was one there.

The capacitor used fir this reason are very small & not noticeable.
Other than that it could be a cold solder joint.
re-flowing the solder on the joints might resolve the problem

[Mike Sulzer]

Well we've all come across pickups with a break in the coil, and that didnt work one bit, right?? So what caused those to not work at all, and these to work?

-Rob

It depends on where the break is. For example, the value of the series capacitance is very small if it occurred right at the connection to the lead wire, but larger inside the coil because of the larger effective area and smaller separation of the two sides of the capacitor.

[Leo_Gnardo]

It depends on where the break is. For example, the value of the series capacitance is very small if it occurred right at the connection to the lead wire, but larger inside the coil because of the larger effective area and smaller separation of the two sides of the capacitor.

Thanks for the explanation Mike. I've never run across this particular pickup and therefor far from expert on it. OTOH if the maker stuck a tiny ceramic cap in series with the coils maybe could get this kind of response and replicate it every time. Heck he might just stop the wind, snip the copper & start the wind again. If you could join those snipped ends together you'd have a working pickup but wouldn't have the thin tone you describe. "There are many strange things in this world." If someone is building purpose-broken PU's and has a market for them (while foxing the experts we have here on MEF) I wouldn't be too surprised.

A) I'd like to see Dave Schwab sound off on this.

B) I see a sort of similarity to those who build or modify purposely lame amps and sell them to the harp crowd who seem to have a ready open wallet for them. They see a need and fulfill it. Doesn't make sense to those of us who try to do everything the "right way" but.... there's a market, even for that. The buyers are happy and the techs are puzzled and that's that. Horses for courses - but in this case it's carnival bumper cars.

[madzub]

I built a tele pup once with a tap at around 5k, 7k on full, and if i had the tap in/out wires not connected to each other, with the full coil engaged, then it got the Nancy tone, and of course a 0 reading on the meter due to the interruption in the coil. I suspect there's the capacitive coupling going on between the inner and outer coils but also perhaps some inductive coupling that fills out the sound better than just using a series capacitor.

[rhgwynn]

So basically, it would have to be a break deep inside the coil where the wires are held together firmly and tight against each other, or all bets are off?

-Rob

[madzub]

the two ends of the break don't need to be held tightly together. this gets me wondering about the capacitive coupling thing. the most coupling there could be between the inner and outer coils is 1 layer, which is aronud 100 turns. that's not a lot of capacitive coupling there. i wonder if most of the coupling, then, is in fact inductive coupling, since you've got 2 coils wound around a common core....

[Leo_Gnardo]

So basically, it would have to be a break deep inside the coil where the wires are held together firmly and tight against each other, or all bets are off?

-Rob

Break deep inside the coil, yes. "Broken" ends of the pickup wire held together firmly & tightly - not so much. I expect the bulk of the wire in the coil will be held together firmly & tightly as in a normal wind. It may not be the usual capacitor model you picture in your mind - two metal plates separated by a non conductive gap as in a disc cap, or a "jellyroll" version of the same as we see in many film & electrolytic caps. In this case, two interleaved coils of very skinny wire separated by a nonconductive "gap" of varnish insulation. It's still two conductive bits separated by a non-conductive gap = a capacitor. See what madzub just posted.

Another possible "test" you might apply, short of unwinding, is this. On the broken-coil pickups I've encountered, the volume control seems to work just fine. BUT the tone control seems to work "backwards."

It would be a hoot to see what a capacitance meter shows when applied to Nancy's Bridge. If you or a friend has one, hook it up & please let us know the results.

If you're set up to wind, why not give it a go yourself? Worst that could happen is you waste a couple bucks worth of winding wire.

If you want to maximize the capacitive effect, might try "bifilar" winding.

[rhgwynn]

Break deep inside the coil, yes. "Broken" ends of the pickup wire held together firmly & tightly - not so much. I expect the bulk of the wire in the coil will be held together firmly & tightly as in a normal wind. It may not be the usual capacitor model you picture in your mind - two metal plates separated by a non conductive gap as in a disc cap, or a "jellyroll" version of the same as we see in many film & electrolytic caps. In this case, two interleaved coils of very skinny wire separated by a nonconductive "gap" of varnish insulation. It's still two conductive bits separated by a non-conductive gap = a capacitor. See what madzub just posted.

Another possible "test" you might apply, short of unwinding, is this. On the broken-coil pickups I've encountered, the volume control seems to work just fine. BUT the tone control seems to work "backwards."

It would be a hoot to see what a capacitance meter shows when applied to Nancy's Bridge. If you or a friend has one, hook it up & please let us know the results.

If you're set up to wind, why not give it a go yourself? Worst that could happen is you waste a couple bucks worth of winding wire.

If you want to maximize the capacitive effect, might try "bifilar" winding.

Don says his Nancy clone has a capacitance of .0035

I didnt mean that the "ends" had to touch. Just that the now two separate strands, had to be laying side-by-side "touching". I wonder if he is braiding/twisting the two strands at all to ensure a "connection"...

I swear though man, I have a beautiful mind or some shet... I've been thinking a LOT about bifilar winding lately... didnt even know it had a name. But I've been wondering how it might change the tone of a pickup...

-Rob

[Leo_Gnardo]

Don says his Nancy clone has a capacitance of .0035

OK, about what we might expect.

I didnt mean that the "ends" had to touch. Just that the now two separate strands, had to be laying side-by-side "touching". I wonder if he is braiding/twisting the two strands at all to ensure a "connection"...

Almost touching, separated by lacquer on the wires. The closer, the more capacitance.

I swear though man, I have a beautiful mind or some shet... I've been thinking a LOT about bifilar winding lately... didnt even know it had a name. But I've been wondering how it might change the tone of a pickup...

Now's your chance to pick up that ball & run with it. Hope you get some worthwhile results.

Send 10% of your profits to .... just kiddin'. Good luck, really!

[big_teee]

It all sounds like Salesmanship to capitolize off the Roy Buchanan's 53 Tele he called Nancy!
I don't know why you would want to make a broke pickup?
Just wind one that sounds good, with measurable turns.
Next we will be discussing the fancy Wraps (Named Rosie, and Roy).
Just my $.02s.
T