Pickup (single coil) placement determination

[rjb]

Some places, companies, make product, then sort them out...
Transistors, sorted for gain and other characteristics, then labeled.

True.

Common sense would dictate the bridge pickup would need higher output because of the strings have less movement. Hence, height adjustments and/or higher output pickup. If i put a lower resonate frequency pickup there, can i throw out turns count (resistance)out the window?

Another reason for putting higher turns on the bridge pickup is to counteract "pingy-ness" by lowering f_c.
Higher Turns -> Higher Inductance -> Lower Resonant Frequency.

[John Kolbeck]

You could just wind them all the same so that you have a fairly uniform resonant peak and Q from position to position, and then control the relative volumes by adjusting the pickup heights.

[mozz]

So inductance differences of 10% won't be heard,but a resistance change of 5% will be? Isn't there a formula for turns and inductance with square roots or something,too lazy to look it up.

[John Kolbeck]

So inductance differences of 10% won't be heard,but a resistance change of 5% will be? Isn't there a formula for turns and inductance with square roots or something,too lazy to look it up.

Resonant Frequency Calculator

Just set the capacitance to 500 picofarads, since that value is dependent upon the guitar cable anyway, set an inductance of 2.5 henries, then hit "calculate" to see the initial value, then tweak the henries value by however much and recalculate to see how much of a difference it makes.

[rjb]

So inductance differences of 10% won't be heard,but a resistance change of 5% will be?

Who said that?
For two coils with the same number of turns, resistance can differ more than 5% just because of differences in winding tension.
Pickup resistance will change by more than 5%, just by playing outdoors in Summer vs indoors in the AC.
(Temperature coefficient of copper is .3862% per degree C)
Temperature Coefficient of Copper

Isn't there a formula for turns and inductance with square roots or something, too lazy to look it up.

So much for the quest for knowledge!

Seeya,
-rb

EDIT:
People these days want everything handed to them!
I remember when we had to bicycle (too far to walk) to the library (uphill into the wind, both ways), to look up information in books made of paper. :grumpy old man:

[John Kolbeck]

Does tension actually increase the resistance, as in, stretch the wire so as to make it a thinner gauge than when it leaves the spool?

[rjb]

Does tension actually increase the resistance, as in, stretch the wire so as to make it a thinner gauge than when it leaves the spool?

Yea, it can.

EDIT:
Even ignoring stretching, the "ohms per 1000 ft" tolerance for #42 wire is about +8.6%/-7.5% from nominal.
http://www.mwswire.com/pdf_files/mws..._5_6_33_34.pdf

Putting it another way, worrying about differences of the magnitude we've been discussing is like picking fly specks* out of pepper.

* euphimism


EDIT II:
Putting it more directly, a 5% difference in resistance don't mean diddly.

[big_teee]

IME magnet wire doesn't stretch too well, it just breaks.
T

[rjb]

Below are recommended winding tension for round magnet wire with Copper and Aluminum conductors. They are strictly recommendations and it is suggested that you use your own validation tests to ensure that the wire is not stretched during your production process.

http://www.mwswire.com/pdf_files/mws...ook/page36.pdf

[John Kolbeck]

That's very interesting. I wonder if mass production pickup winding machines maintain a higher tension on average than hand guided pickups. If that's the case, it could represent a substantive difference between hand guided and machine made pickups that's a lot more credible than scatter winding.

[Lollar Jason]

if you pull slowly on a longish piece of magnet wire intending to break it youll see it stretch before it breaks. Difference in tension could also result in a larger diameter coil if its really loose- a larger perimeter means a longer loop of wire per turn- longer length means more resistance so stretching the wire isnt always the reason for higher comparative ohms. I wouldnt say "production winders" maintain higher tension. Tensioning requires monitoring to make it consistent