Author Topic: Rewinding Rhodes Pickups  (Read 8915 times)

Offline eallen4

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Rewinding Rhodes Pickups
« on: December 19, 2010, 10:01:25 AM »
Hi folks - after 5 months of not being used, it appears that 3 dead pickups have developed on my Mark I Stage 73 Rhodes.  i have found the helpful info on pickup maintenance and rewinding at "http://www.fenderrhodes.com/service/rewinding-pickups.php" but it doesn't describe a total rewinding of a pickup.

what i'm looking for is the correct wire gauge and the number of windings that should be used.

if anyone has that information or a link, i'd sure appreciate it. 

i am curious why this problem would "suddenly" develop after owning the instrument for 25 years, and whether this indicates future problems to come with the other pickups (like a materials problem).

thanks - ed in  orlando

Offline sean

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Re: Rewinding Rhodes Pickups
« Reply #1 on: December 20, 2010, 11:35:49 AM »

Hey Ed,

If I were you, I would try 38AWG enameled wire.  The hardest part will be constructing a little jig to make the winding practical.  If you build a little jig that can be driven by a hand-drill, we would love to see pictures of it.

You will definitely spend more time and money than just purchasing new pickups.

From an old post:
Well, I unwrapped two pickups, one from a 1981 white-tape-wrapped lot, and another from a 1973 clear-tape lot.
Both wires measure ~0.0045 inches in diameter, measured with a dial caliper that is is of reasonable accuracy. 
So, my guess is that it was 38 AWG enamelled wire, supposedly .004" in diameter.
36 AWG would be .005" in diameter, and will probably work fine.
I wouldn't really want to use anything smaller (too delicate).  My guess is that it is less than 2500 windings, but I will let somebody else count that.
(From http://ep-forum.com/smf/index.php?topic=5055.msg24955#msg24955)

=============

The pickups do die from old age.  They don't like to be near moisure, salt, nor Disney World.  So, you see, well....

If the enamel gets scratched or worn off, then the copper wire will eventually corrode.  Sometimes you can see the little green dot of corrosion on the pickup where the wire bends over the edge of the bobbin to connect to the solder terminal.  Sometimes the wire will corrode all the way through, sometimes the wire will simply get weakened and die from exposure to heat (a hot afternoon in the car might expand the bobbin enough to stretch the wire past the breaking point).

The later seventies pickups seem to be the worst.  I guess the enamel wire that was used in the early years had adequate thick enamel coating.  The wire used in the late seventies seems to have failed more often.

Sean




Offline eallen4

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Re: Rewinding Rhodes Pickups
« Reply #2 on: December 21, 2010, 09:10:25 PM »
sean - thanks for the help and the reference info from the forum.  i see that guitar pickups typically use 42 AWG wire, but based on the data from the two pickups cited, i think i'll try it with 36 AWG first.

on one of the three dead pickups, i can see a green dot where a wire turns the corner of the pickup bobbin and figured that was copper corrosion.  given the fact that i'm about 15 miles away from Disney World, i am starting to worry about the life of this very great sounding keyboard.  the worst case scenario is buying pickups at $15 a pop time 73 notes = a cool thousand semolians!  (or going into the pickup rewinding business as a sideline to playing music).

thanks again - ed

Offline vanityduluoz

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Re: Rewinding Rhodes Pickups
« Reply #3 on: January 17, 2011, 09:28:49 PM »
Hey Ed,

Did you have any success rewinding your Rhodes pickups?

I just purchased a Rhodes piano that I knew had pick-up issues. The seller was out of Tampa, Fl, and the Rhodes was stored in a garage for a few months. I think the Florida humidity just wrecks these guys. When I got the Rhodes home, I tested the resistance/inductance of the pickups only to discover that I had 43 dead pickups (far more than I ever imagined). I examined a pickup under a microscope and noticed the green oxidation on the copper wire as well.

I am going to try rewinding the pick-ups as well, because I am definitely not financially able to replace all the pickups.

I hope you are successful with getting these pickups up and running again. Any tips or tricks you discover would be sincerely appreciated.

K


Offline 4kinga

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Re: Rewinding Rhodes Pickups
« Reply #4 on: January 18, 2011, 01:27:40 PM »
vanityduluoz:

You can try a method I've employed with some success:

If the break is close to the post, you can
- scrape the enamel from the wire and fold over. 
- Create a short leader from spare wire and scrape the end. 
- Create a loop/hoop on the leader.
- Thread the pick-up wired through the loop on the leader and solder.
- Solder the leader to the post.

Measure the pick-up with you dvm. 

Not sure how well it stands up to heavy touring, but in controlled environments, it works well.

There was a short discussion a while ago about a possible preventative method, but I don't believe it got far.

Also, while you're doing all that, you might as well replace all grommets since the pick-up jobs going to be allot easier with the tine off.

Offline eallen4

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Re: Rewinding Rhodes Pickups
« Reply #5 on: February 13, 2011, 04:57:43 PM »
K - a wise friend suggested i buy three scavenged pickups to the replace the three dead ones, and then experiment with the rewinding process.  i have just replaced all three successfully. 
i first tried doing the J-hook process to bridge the oxided point on the magnet wire but have to say that this was about as challenging as neuro-surgery for me (although i've never tried the latter).  suffice to say that didn't work. 
i'll try to get back to this forum after i've tried rewinding them, but it may be awhile since the keyboard works now. 
good luck with your piano. - ed

Offline eallen4

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Re: Rewinding Rhodes Pickups
« Reply #6 on: February 16, 2011, 10:07:05 PM »
 :o Just for info, i measured the wire diameter of one of the pickups removed 0.0045 inches which agrees with info posted by someone else on the forum.  this is exactly AWG 37.  FYI - Ed

Offline vanityduluoz

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Re: Rewinding Rhodes Pickups
« Reply #7 on: February 22, 2011, 01:38:22 PM »
Thanks so much for the info!

By any chance, do any know what type of wire is used to connect the pick-ups? I see that it is available on the vintage vibe website:

http://www.vintagevibe.com/p-722-pick-up-wire.aspx

I purchased a couple feet, but I think I may need more to replace all 43 dead pick-ups. It may be more economical for me to purchase a spool through a electronic supply store rather than by the foot through vintage vibe.

Offline Rhodesman73

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Re: Rewinding Rhodes Pickups
« Reply #8 on: August 08, 2012, 11:51:31 AM »
I have some extra pickups for sale on eBay for $5 each plus mailing.  They've been cleaned and have been checked.
sean - thanks for the help and the reference info from the forum.  i see that guitar pickups typically use 42 AWG wire, but based on the data from the two pickups cited, i think i'll try it with 36 AWG first.

on one of the three dead pickups, i can see a green dot where a wire turns the corner of the pickup bobbin and figured that was copper corrosion.  given the fact that i'm about 15 miles away from Disney World, i am starting to worry about the life of this very great sounding keyboard.  the worst case scenario is buying pickups at $15 a pop time 73 notes = a cool thousand semolians!  (or going into the pickup rewinding business as a sideline to playing music).

thanks again - ed