Dead DeArmond Rhythm Chief 1000

[Mark Norwine]

I have a dead RC1000 on the bench. And not just "dead", but "Really most sincerely dead". Between the glue & the rust, the coil came out in pieces.

Does anyone have a clue the number of windings a.) around the 4-pole and then b.) around the rest?

Any guess on wire size? This stuff feels like spider silk. If I had to guess, I'd say #45 or #46.

Anyone know for sure?

Thanks!

[John_H]

I think board member belwar has done some pretty extensive research on these. You might check with him.

[big_teee]

I have a dead RC1000 on the bench. And not just "dead", but "Really most sincerely dead". Between the glue & the rust, the coil came out in pieces.

Does anyone have a clue the number of windings a.) around the 4-pole and then b.) around the rest?

Any guess on wire size? This stuff feels like spider silk. If I had to guess, I'd say #45 or #46.

Anyone know for sure?

Thanks!

Did you look at this post?
David S. just did this one with pictures.
Don't know if this is the same pickup or not.
http://music-electronics-forum.com/t31801/

[Mark Norwine]

Interesting thread.....yes, that's the same pickup.

I see that he didn't do a separate winding for the E_A_D_G, but decided to just to "one full winding". I may elect to do the same. Indeed, I was contemplating such; this just pushes me further in that direction.

I don't have any #44 in stock...I wonder how many turns of #43 I could fit? Probably enough that the results would be "just fine"....

[big_teee]

You may want to buy a roll of this.
It is handy to have around, even though you don't need it often.
I use it for Strat Sized bridge blade bobbins.
44 AWG Enameled Copper Magnet Wire - Mini Spool Details | Remington Industries

[Mark Norwine]

Indeed, I just may!

The bobbin flanges are thin (.017"). I salvaged the top flange, but the bottom one disintegrated on removal....and the little magnet "blocks" dislodged from both.

I've fabricated a new bottom flange from 2 business cards glued together, and rebuilt the bobbin with the original top flange and some epoxy. I left the E & B magnet block out, in anticipation of rewinding this "stock", but I'm pretty sure I'll glue the B & E block in place & wind like David did....."one, big coil".

So, yeah, having come this far, why dink around with the wrong wire size? I'll get a small spool of #44 and re-wind this as close to correct as I can....

[David Schwab]

Indeed, I just may!

The bobbin flanges are thin (.017"). I salvaged the top flange, but the bottom one disintegrated on removal....and the little magnet "blocks" dislodged from both.

I've fabricated a new bottom flange from 2 business cards glued together, and rebuilt the bobbin with the original top flange and some epoxy. I left the E & B magnet block out, in anticipation of rewinding this "stock", but I'm pretty sure I'll glue the B & E block in place & wind like David did....."one, big coil".

So, yeah, having come this far, why dink around with the wrong wire size? I'll get a small spool of #44 and re-wind this as close to correct as I can....

Did you see my thread here where I rewound a Rhythm Chief?

[big_teee]

Did you see my thread here where I rewound a Rhythm Chief?

You need to start reading from the beginning.
I've already posted your link, and been bragging on your pictures and post!

[David Schwab]

You need to start reading from the beginning.
I've already posted your link, and been bragging on your pictures and post!

I did, but I missed your link.

[Mark Norwine]

ok...here's a dumb question:

Can magnets "die"?

The magnets in this bobbin had almost no "pull" to them at all. After recharging them, they're still.....dead. Won't hardly pick up a razorblade from 1/4" away.

My gauss meter is constructed into a jig for (only) measuring bar magnets, so I can't really get a reading / provide numbers.....but these things are just dead!

Can these magnets have simply had enough? Does that make sense?

EDIT: I just stacked six (6) Neos 3" x 3" x 1/2" and parked this bobbin on top for 5 minutes. Took it off, and........it will not pick up a razor blade from 3/8" away.

Sure sounds dead to me......

EDIT2: So my brain says "hey.....since I don't know what kind of AlNiCo these 6 slugs are, maybe they're an anisotropic and would be happier being charged in the other direction!"

So in the course of setting up my neos to re-re-charge this bobbin, I manage to smash a neo into the delicate bobbin and shatter the original (0.017" phenolic) top plate.

Game over. Time to punt & start over.

We now return you to your regularly-scheduled programing.

[ken]

I tried to fix one of these once too years ago. NEVER AGAIN. I pity you, and you can kiss your sanity goodbye. I had to basically reconstruct the whole thing from scratch.

No, the magnets cannot completely 'die', it's illogical. I thought once possibly only one or two of the bigger 'magnets' were real magnets, and maybe the others were just polepieces? All I knew was that I couldn't magnetize mine either, and after a rewind it still worked.

ken

[Electricdaveyboy]

I did a rewind on a RC1000 there must be pics in a thread somewere on this forum.I still have the pickup, it was fun to do.
If I would have the time I would do a clone but if I rememer right I´ve been thinking on this for more than 5 years now and there is no light in the end of the tunnel.
;-)

[David Schwab]

Short alnico magnets like that can lose their charge. The baseplate on the pickup is steel, which works like a keeper, but the pickup I had in to rewind needed to have the magnets recharged, as they were very weak.

So it is possible for the magnets to lose their charge over time.

All the poles in the RC are magnets.

[Mark Norwine]

lose their charge....of course.

But "completely fail to take a new charge"? These things won't get any stronger from their virtually-dead state.

Granted, they're puny little slugs, but still.

[big_teee]

lose their charge....of course.

But "completely fail to take a new charge"? These things won't get any stronger from their virtually-dead state.

Granted, they're puny little slugs, but still.

Did you test them recharged sitting on the steel baseplate?
They won't have to be real strong if you can get them to hold a charge at all.
You may try reversing the charge and see if they charge up better that way?