Pickup winding....


James8831
Senior Member
Joined: 10/29/01
Posts: 510
I wind my own pickups ( scatter wound- good sound, a bit fragile but comparible to midlevel single coils),
and would like to know if anyone knows if putting a resistor
in one of the conductors would actually have an effect on the PU, and in which way?

To put it bluntly could i get away with a thousand or so winds and get away with putting an appropriate value resistor in to make up impedance/level, instead of having to do X thousand winds.


Thanks for any help.
Accuracy,you say? hmm interesting concept..
# 1
Lordathestrings
Gear Guru
Joined: 01/18/01
Posts: 6,242
I replied to your post in the Gear section, simply because I came across that one first. This section is dedicated to more in-depth discussion, so I can go into a little more detail here.

Impedance is a frequency-dependant characteristic. That's why PU specs quote something like "1.2 k Ohms @ 1 kHz".

The impedance of an inductor is calculated as:

Z = 2 x pi x f x L where

Z is the impedance, in Ohms.
pi is the ratio of a circle's circumference to its diameter.
f is the frequency, in Hertz (cycles per second), and
L is the inductance of the coil, in Henries

You might see this formula written as Z = wL. w is the angular velocity of the current or voltage waveform at a given frequency. It is calculated as 2.pi.f, so you can see it all comes to the same thing.

Resistance is calculated as:

R = E/I where

R is the resistance, in Ohms
E is the voltage (Electromotive force), and
I is the current, in Amperes

You can see that while the impedance of a coil will change in direct proportion with the frequency, its resistance will not.

The resistance and inductance of a coil are fixed values that are determined by its physical properties. Because the two appear in series, the impedance can never be less than the value of the resistance. At DC, the frequency is 0, so there is no impedance due to inductance, but the resistance is always there.

As the frequency increases, the impedance of the coil increases. It usually becomes much larger than the resistance, which remains the same as it was at DC.

Lordathestrings
Guitar Tricks Moderator

www.GuitarTricks.com - Home of Online Guitar Lessons
# 2
James8831
Senior Member
Joined: 10/29/01
Posts: 510

Thanks for your reply, Lordfothestrings (sp) i will try and digest that over a few days and work it out(?)

I'm not good at electronics, but I can do the "sticking it together" bit ok, so i guess it's back to school for me!

Thanks for your very informed answer anyway.

James.
Accuracy,you say? hmm interesting concept..
# 3
James8831
Senior Member
Joined: 10/29/01
Posts: 510
Sorry - shoulda said "Thanks... Lordathestrings..." not Lordfothestrings..
Accuracy,you say? hmm interesting concept..
# 4