DC Resistance after potting

[MistaT]

Yes I can certainly live with that. However this is the first time I have had that small of a difference in resistance. Usually the difference before and after potting for has been .5k to .9 k This is the first one that was only .2 k difference.

I am trying to figure out what I am doing to have such a big change in resistance in the other pickups, and what I have done on this one pickup that gave me an acceptable change for once.

[MistaT]

Gentlemen,

I think I finally have a handle on my situation. To recap, my problem was that I was seeing a significant resistance increase ( 0.5-0.7k ) after my pickups were potted. For whatever reason, it seems that I need to let my pups sit for an hour or so before I pot them. As has been mentioned earlier, a pickup will show a slightly higher resitance right after being wound (0.1 - 0.2K). So, for me at least, I need to check the resistance right after winding, then wiath until it has cooled. Apparently a good indicator is a 0.1 - 0.2k resistance drop..

I just finished building 3 pickups using this procedure, and I was able to hit my desired resistance every time. What exactly is going on I don't know, perhaps Bill M's theory about too much tension at the beginning of the wind.

Nonetheless, it appears that I have my process under control now. Thanks everyone for all of your help! I greatly appreciate it! I hope to be able to return the favor someday!

-- Mike

[David Schwab]

I just finished building 3 pickups using this procedure, and I was able to hit my desired resistance every time. What exactly is going on I don't know, perhaps Bill M's theory about too much tension at the beginning of the wind.

Mike, generally it's better to wind to a certain number of turns, and not the DC resistance. I check the resistance after I wind a coil to see if the coil is good, since I know what it should read, but I never wind to a resistance.

And yes, the number is sometimes a little higher than "normal" right after winding, but I can wind four coils and have them all right on the mark.

Did you try the pickups out yet?

[MistaT]

Thanks David,

actually it makes more sense to wind to a specific number of turns rather than a specific resistance. Since it seems to to me that more turns = more output, and the fact that the formula for a resonant circuit only involves inductance and capacitance, and not resistance.

Which to me begs another question, why do people seem to place so much emphasis on resistance rather than on number of turns?

As far as trying the pickup out, no I haven't yet. I am still in "learning mode". But I am anxious.

Again thanks for everyone's input! I appreciate it!

-- Mike

[David Schwab]

Since it seems to to me that more turns = more output

All other things being equal, yes.

Which to me begs another question, why do people seem to place so much emphasis on resistance rather than on number of turns?

I would guess that as an end user, that's all the information you have without taking the pickup apart!

So people got used to seeing DC resistance, and if it was a hot PAF type pickup, you could use a standard one to see the relative increase in the amount of wire on the pickup.

So it's a way to give some info without giving away your formula.

[MistaT]

Gotcha!

Thanks again!