Changing Coil AWG Mid-Wind

[PoorMan]

I have a particular coil that I'm going to need to use 43 AWG to get a DC rating I'm after and I'm considering switching to 42AWG mid-wind to increase the size of the coil (coil will be smallish with all 43AWG and I can't get enough wire on it with 42AWG)

I can't imagine I'm the first to try this...Has anyone here experimented with this? What were your findings?

[David Schwab]

Why do you need a certain DC resistance?

[NightWinder]

Fusion

Thats what I call a fusion wind. Welding 2 different wire sizes after forsaid amout of turns. Very risky for shorts, but as long as you reinsulate your weld properly and do not weaken the wire with too much heat, you'll be ok. You'll need to pot this one. Hopefully time is on your side as well, whatever method you use to insulate will take time- Perhaps 3 coatings for insurance purpouses.
You can always simply strip it off and start over...

[PoorMan]

Why do you need a certain DC resistance?

I'm trying to get modern P-90 output on a small Strat style bobbin. It's one of those S-90 designs with dual ceramic mags on the bottom and fillisters. In trying to keep as much like a P-90 as possible (within the limitations of the design), I want a big coil with 8k+ wire on it. But I can't get 8k of 42 on it and I suspect (I haven't tried yet) 43 will make a small coil.

I realize the coil will not be anywhere near the size of a real P-90 either way...just trying to do all I can.

[SK66]

I've done similar to get a hotter pickup without overly choking the tone. Or to get a coil shape desired (also important to tone) BTW, output is determined by turns, not dcr. I think that's why David was questioning. To get the coil size you could first wrap the coil with tape or similar, but this will have some affect on tone.
I simply coat the joint in superglue (1 coat) and then glue it to the rest of the coil with another drop (I use poly primarily). Wrap it a few turns by hand to prevent stretching the joint and proceed normally. Of course, the coil is then non-repairable due to the glue, but I find it very reliable and does not need potting any more than any other coil with similar windings.

[SK66]

I'm trying to get modern P-90 output on a small Strat style bobbin. It's one of those S-90 designs with dual ceramic mags on the bottom and fillisters. In trying to keep as much like a P-90 as possible (within the limitations of the design), I want a big coil with 8k+ wire on it. But I can't get 8k of 42 on it and I suspect (I haven't tried yet) 43 will make a small coil.

I realize the coil will not be anywhere near the size of a real P-90 either way...just trying to do all I can.

Just stuff it full if using 43.

[PoorMan]

I've done similar to get a hotter pickup without overly choking the tone. Or to get a coil shape desired (also important to tone) BTW, output is determined by turns, not dcr. I think that's why David was questioning. To get the coil size you could first wrap the coil with tape or similar, but this will have some affect on tone.
I simply coat the joint in superglue (1 coat) and then glue it to the rest of the coil with another drop (I use poly primarily). Wrap it a few turns by hand to prevent stretching the joint and proceed normally. Of course, the coil is then non-repairable due to the glue, but I find it very reliable and does not need potting any more than any other coil with similar windings.

Ah! Excellent point. I misunderstood the nature of David's question (and didn't really think through what I was saying either).

[Dave Kerr]

Someone else had a nifty solution to this - add a 3rd eyelet, terminate the inside portion and begin the second portion from there.

[SK66]

Someone else had a nifty solution to this - add a 3rd eyelet, terminate the inside portion and begin the second portion from there.

That also gives you the option of two "output levels".
I've done this for cases where someone wanted both a high gain pickup AND a vintage low output pickup in one. This is truely what a "coil tap" is. (switching a HB into a singlecoil is "coil cutting")

[PoorMan]

Just stuff it full if using 43.

That won't push me past the range of typical P-90 output? (I guess I can always try and find out)

[SK66]

No, you'll be lucky to get enough turns in there to get the same tone/character. 43awg to 10k is about right. (P-90=10,000 turns 42)
I usually overwind a bit from there due to coil shape/size to get the right character (aprox 12k).

[PoorMan]

No, you'll be lucky to get enough turns in there to get the same tone/character. 43awg to 10k is about right. (P-90=10,000 turns 42)
I usually overwind a bit from there due to coil shape/size to get the right character (aprox 12k).

Great info! Thanks SK!

[David Schwab]

BTW, output is determined by turns, not dcr. I think that's why David was questioning.

Yes, that was it.

But I didn't know what he had in mind.

[David Schwab]

No, you'll be lucky to get enough turns in there to get the same tone/character.

Maybe with 44 AWG?

[SK66]

Maybe with 44 AWG?

I generally try not to go more than 1 step from "original" if I'm trying to retain the same tone/character... It can be done with 43 with technique (it won't allow for a lot of scatter)