| Author |
Topic: Pickup Question |
Richard Sinkler
From:
aka: Rusty Strings -- Missoula, Montana
|
Posted 26 Apr 2015 8:49 am |
|
This is strictly for my own education.
In the Pedal Steel section, Dave Zirbel asked bout one string being dead in his pickup.
http://bb.steelguitarforum.com/viewtopic.php?t=283450
On a pickup like Dave has, Is each pole piece wrapped in it's own coil? If one coil wraps all pole pieces, how could a pickup need rewinding (as someone mentioned might be the problem) if only one pole piece is not working.
_________________
Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, Recording King Professional Dobro, NV400, NV112,Ibanez Gio guitar, Epiphone SG Special (open D slide guitar) . Playing for 55 years and still counting. |
|
|
|
James Hartman
From:
Pennsylvania, USA
|
Posted 26 Apr 2015 9:50 am
|
|
Pretty sure the pickup in question is standard Gibson humbucker construction, although for 8 strings. In which case, the pole pieces are steel slugs in one coil and screws in the other, two coils with a single bar magnet beneath the coils.
There have been a few pickups made with independent coils for each string but the only such I'm aware of were custom built for boutique instruments.
You ask a reasonable question. If a coil (or both coils?) sustained damage it (they) would not function for any of the strings. I can't figure out how an electrical fault would not effect the whole coil and thus all strings.
No one's offered a plausible answer to the question asked in the thread you cite. Nor can I. I'm curious if there is actually no signal as stated or, rather, a weak signal from the one string. Has that one pole piece somehow lost contact with the magnet?
Puzzling... |
|
|
|
Stephen Cowell
From:
Round Rock, Texas, USA
|
Posted 26 Apr 2015 10:02 am
|
|
Richard, either one or two magnets do everything, or there's one magnet for each pole. Nobody winds a separate coil for each string.
The pickup shown in the link is typically a humbucker, with one magnet between the pole pieces... here's a picture:
The gray bar in the middle is an alnico 2 magnet, polarized for north on one coil and south on the other (across the short dimension).
If one string appears dead on this type of pickup then the magnet may be cracked, loose, or have lost magnetism on part of it. It is also possible that the coil has become shorted/open, and the weakest string shows the deficit the most... that would normally be the high string on the end.
Magnets can be re-magnetized... ceramic magnets normally don't need this, but alnico is known to degrade over time.
_________________
Too much junk to list... always getting more. |
|
|
|
Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
|
Posted 26 Apr 2015 10:08 am
|
|
Interesting thread.
One could tap on each magnet with a small steel screwdriver and expect to hear clicks in the speaker if the magnet is doing its job. I suspect the pole piece has lost contact with the main magnet, or depending on the construction, lost its magnetism. This can happen if the pole piece has been struck with a hard object or subjected to heat. Both seem unlikely.
Hpoe we get to hear how the story ends.
Craig Baker 706-485-8792
cmbakerelectronics@gmail.com
C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024
_________________
"Make America Great Again". . . The Only Country With Dream After Its Name. |
|
|
|
Richard Sinkler
From:
aka: Rusty Strings -- Missoula, Montana
|
Posted 26 Apr 2015 10:11 am
|
|
Thanks guys.
_________________
Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, Recording King Professional Dobro, NV400, NV112,Ibanez Gio guitar, Epiphone SG Special (open D slide guitar) . Playing for 55 years and still counting. |
|
|
|
Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
|
Posted 26 Apr 2015 10:24 am
|
|
Stephen,
Great drawing. Really breaks it down and makes it easy to explain.
Craig
_________________
"Make America Great Again". . . The Only Country With Dream After Its Name. |
|
|
|
