DCR per meter

[jnohlic]

Hello,

There is this pickup I like very much from the EGC guitar brand. The pup was filled with epoxy.
It is a single coil with an aluminum cover. The DCR is 9.

Does anyone know the DC resistance per meter of the different kind of wires so that I can try to reproduce it.
In other terms I would like to deduce the number of turns from the DCR.

Any tips on how to try to reproduce a pickup without unwinding it ?

Thanks

[big_teee]

Can you get us close to what you are trying to reproduce? Like a picture?
Also could you update your profile, to show your location?
We all like to know where guys reside! It helps on part availability, and such!
Thanks,
Mod- T

[jnohlic]

Hello,

I tried to update my profil but it does not seem to be working. I will try again later.
I live in Paris, France.

I will send pictures of this EGC 7 string pickup as soon as I can. It won't be before sunday night as I'm away for the week-end.

But still, I'm wondering : does it make sense to try to deduce the number of turns using the DC resistance per meter ?

thanks,
Julien

[big_teee]

Hi Julien:
Welcome!
I see Paris on your Profile, so yes it did update, thanks.
I have Data for a 7 string humbucker.
I can calculate for a SC if I have bobbin core dimensions?
Here's a 7 string humbucker bobbin. Which will give a little idea.
http://music-electronics-forum.com/a...1-14-05-09.png
T

[J M Fahey]

Hey big tee, congratulations !!

Nice piece of software you wrote

I had thought you Pickup guys went more on the empirical/experience side of things than the Math/Engineering side .

Loved the corrections for "Real World" results (loose/ tight hand winding) , way to go

[big_teee]

Hey big tee, congratulations !!

Nice piece of software you wrote

I had thought you Pickup guys went more on the empirical/experience side of things than the Math/Engineering side .

Loved the corrections for "Real World" results (loose/ tight hand winding) , way to go

I can't take the credit!
The Estimator was Solely written by Salvarsan.
I simply add and remove data with a linux text editor I use, called bluefish editor.
I have a fairly extensive library of pickup data, that I keep just for this B/H Forum use.
I don't post it anywhere but here.
Here is a link to the Salvarsan version.
Coil Estimator
My library version I keep on my laptop.
T

[SonnyW]

Does anyone know the DC resistance per meter of the different kind of wires so that I can try to reproduce it.
In other terms I would like to deduce the number of turns from the DCR.

Any tips on how to try to reproduce a pickup without unwinding it ?

Thanks

To answer the original question, here is a link that I have found to be very useful. Technical Data by Size

I do a lot of rewinds where the original coil is present but it is open. So I weigh the wire out very precisely and use the ohms/gram data from these tables to calculate what the original resistance must have been. To do this I have to also measure the wire diameter to determine which size of wire to look up in the tables. I then use the coil estimator to calculate the number of turns to reproduce it with.

I suppose this method could also be used if you know only the DC resistance of the coil, but you would have to guess at the wire diameter if you can't see it because of epoxy potting or whatever.

[jnohlic]

Thank you for you very interesting answers,
Here is the pup :




The Cover heigth is 16,5 The magnet height is about 14mm (It is not possible to measure properly)
The steel base plate height is at least 4mm but I don't see all of it.

The pole spacing from center to center is 62 mm
Each pole is 5mm diam

The wall thickness of the cover (I can only measure the sides) is : 1,65mm
As said before the DCR is 9.

Thank you

[kayakerca]

Thank you for you very interesting answers,
Here is the pup :

[ATTACH=CONFIG]40592[/ATTACH]
[ATTACH=CONFIG]40593[/ATTACH]

The Cover heigth is 16,5 The magnet height is about 14mm (It is not possible to measure properly)
The steel base plate height is at least 4mm but I don't see all of it.

The pole spacing from center to center is 62 mm
Each pole is 5mm diam

The wall thickness of the cover (I can only measure the sides) is : 1,65mm
As said before the DCR is 9.

Thank you

I rewound a Riki neck pickup a while back that had that same "hole through the magnet" setup as in your photos. It was extremely low output for the DCR. I changed it to a P90 type setup with a pair of A5 bar magnets on either side of the screws, but without a keeper. The output increased many fold and the player loved the tone of the rewind and new magnet configuration.

From:



To:

[mr fab]

the pickup looks like a 7 string p90 with magnet poles

i dont think it would be hard to wind up a set, once you find the source for 7 string p-90 parts

it most likely used awg43 wire given the dcr of 9k

[jnohlic]

Hello,

That is an interesting comment,
What makes you think it is a P90 with magnet poles ?
Can you tell me more abaout P90's with magnet poles ?

@ Kayakerca (but maybe Mr Fab has thought the same) : the base plate is non magnetic, it is just steel or at least looks like it.

I would be curious to learn more about "hole through the magnet" pickups ? But maybe I should start a new thread about that ?

@ Big Tee : I read your message about inches and centimeters after I wrote this one. I will uses inches from now on.
Do you think there are enough data for your software ? The bobbin height is not really clear...

thanks