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Post by Runewalker on Apr 14, 2006 7:29:41 GMT -5
Getting too many Pups from strips and excess inventory. Need to catalog and store properly.
A. Testing. Is there a test (available to the hobbyist who does not have access to the R&D dept of National Instruments) to identify polarity and wind direction? I assume wind direction on single is really just color coding, but how do you assess the the Polarity? I have what I suspect is a mid RWRP, but would not know currently without installing it.
B. Proper storage. All that north-south stuff would suggest there is an alignment protocol when storing pups adjacent to each other, such that magnetism remains unaltered over a storage life span. But what is the proper way to line these sucker up. Stack them on top of each other, output wires on the same side? Next to each other in a row? Back to back, left to right, end to end? Now I'm lost.
Thanks in Advance, Nutz.
RW
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Post by sumgai on Apr 14, 2006 16:13:31 GMT -5
Rune, There is one fairly easy test, with a small proviso.... This test is much easier if you have an older, or even a new but cheap, analog multimeter. That way, you can watch the direction the needle swings, instead of having to watch the digital meter's face for the negative sign. Set the meter to it's lowest AC voltage range, and connect up it to the pickup. Presumably, there's a black pickup lead intended to be called ground, so that'll go to the meter's negative test lead. Tap a pole piece, and see which direction the needle swings. (If it went "lower than zero", don't worry, you're just interested in the direction, not the absolute value.) Now hook up a similar pickup the same way, and tap that one. Did the needle swing the same direction, or the opposite? Try all of them until you have a fair idea of which coils are "normal", and which ones are more likely to be "RWRP". Alternatively, compare them with absolute known good pickups than can be readily identified as to polarity, etc. Store them as if they were in a display box on a retail store counter or shelf. The spacing you find in those boxes is good enough to ensure that the magnets won't "leak down" in strength over the next several years. "But that takes up too much space in my intended storage area", you retort. Well, that's why they say that eBay is your friend!  HTH sumgai |
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Post by dunkelfalke on Apr 14, 2006 17:43:16 GMT -5
there is an easier possibility for finding out the rwrp ones.
just take a pickup you know is normal wounded and try to stick it do the pickup you want to test.
if it sticks it is rwrp.
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Post by ChrisK on Apr 14, 2006 19:08:45 GMT -5
I could be misinformed, but I don't give a hoot about wiring polarity.
What matters is magnet polarity alone, unless you're dealing with a shielded (braided) one conductor pickup cable. Then you can have grounding issues.
The magnet polarity determines the flux polarity. The string's instantaneous direction thru such determines the induced voltage in the coil (right hand rule). Wires can be switched aboot with general abandon.
What matters is magnet polarity alone.
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Post by Runewalker on Apr 14, 2006 21:38:42 GMT -5
I'll defer to the folks like CK who know about this stuff. You just see RW with the RP (RWRP) on the mid singles of 3 single sets. Do you know how to physically reverse a single coil's polarity? The ones with ceramics I see normally have a slab of ceramic glued to the bottom of the bobbin, sometimes 2 small ones on either side of the poles sticking below the bobbin flat. So that is pretty easy to see what component needs to be turned 180 degress, assuming you can release the glue. I am looking at some alnicos and see only the bobbin, top and bottom flats, 42 or 43 g winding and six staggered pole extending throught the middle of the bobbing. Is there a way to reverse the polarity in these? I guess I can't see the bar magnet in the alnicos, that your would turn 180degrees. pix us.st11.yimg.com/store1.yimg.com/I/yhst-50206111187217_1891_5417683What am I missing here? |
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Post by sumgai on Apr 15, 2006 0:12:47 GMT -5
Rune, I don't know that you're missing anything, at least, not in my experience. Alnico magnets are much stronger, ounce for ounce, than ceramic ones. I've never seen a single coil pickup with any kind of "helper" magnet hanging off the underside - the pole pieces themselves are the magnets. (In the vast majority of humbuckers, what I just said is not true.) All that said, Chris would be upset if he continued to "not care" about which way the wiring goes, thinking that he can reverse it at will. Chris, you quoted the 'right-hand rule', and you were correct to do that, but in point of fact, winding a coil in reverse of the ordinary direction is really just keeping the winding direction in concert with the magnetic direction. All pickups (within one given guitar) are generating current flow in the same direction, but due to the magnetic reversal, the current flows are opposite each other, thanks to the right-hand rule! A single coil doesn't matter, even when compared to an adjacent single coil pup. However, when we set out to design a humbucker, we simply must take these facts into account. If we don't, we get what you and I call "out of phase" sounds. I'm sure you'll agree, these are not what the general buying/playing public is looking for, nor expecting either.  If nothing else, I'd like to pose one question to you. If the wiring direction made no difference, then why would virtually all pickup winders reverse the winding direction when they reverse the magnetic field? I would find it hard to believe that there's been a "little man behind the curtain" all this time, and that we've been fed a bunch of "clean hogs", as unklmickey would put it.  Just trying to start something here, that's all.  This goes to the heart of modding one's guitar in search of usable tones. If we're just poking around in the dark, then we'll never find what we're after, right? Let's see if we can't nail this puppy down and get it right. I'd rather eat crow now, if I'm wrong, than continue designing circuits based on faulty knowledge. sumgai |
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Post by ChrisK on Apr 15, 2006 16:54:23 GMT -5
Well,
...is in fact a fairly profound simple statement.
The thing that's hard(er) to change is the magnet polarity. An AlNiCo single coil often has the wire wound directly over the bar magnets, which are electrically conductive. Don't try to mechanically fool with these.
You can reverse the magnetic polarity thru exposure to a stronger magnet. StewMac sells a neodymium magnet and kit for this porpose, but I can't speak to its effectivity.
Ceramic single coils have a (non-conductive ceramic) slab affixed underneath to plain steel pole bars, if you can get this off, you can reverse the magnetic polarity.
Side by side humbuckers, aahh! Yep, one can indeed remove and reverse the slab magnets. I've done it often enough to have looked for a wax re potting method that doesn't involve a double boiler (you all DID use one and not just a single pan paraffin fire bomb), it's called a hair dryer, an aluminum pie pan, and wee bits of wax.
As to , I stand uncorrected.
If the magnetic polarity is correct (opposite) betwixt two coils regardless of where they live (a side by side humbucker or two single coils), then, and only then, reversing the wiring on one coil (and hence its phase) is all that's needed to ensure some degree of hum canceling. Winding direction is meaningless externally. It's a coil, of a given winding direction, terminated to two (hopefully) externally ambidextrous wires.
If I have two AC transformers with the inputs wired in phase, then the outputs, if connected together, must also be in phase. If I wire the inputs out of phase, then the outputs must also be out of phase, for the result to be in phase.
Two RWRP pickups have three phase relative components; the first is the magnet polarity (RP), the second is the wiring direction (RW), and the third is the instantaneous string vibrational direction. Since the third is difficult to change (unless you're doing some serious hyperspace dewobbulation), the first two are of interest.
Since the magnetic polarity is much more of a pain to reverse, while the coil is eminently reversible, for the general rewiring hobbiest......
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Post by wolf on Apr 15, 2006 22:55:09 GMT -5
The windings of the 2 coils in a humbucker actually go in the same direction. Please visit my website page here: www.1728.com/guitar1a.htmand start reading at the part that says ... The other requirement for a humbucking pickup is that the coils are reverse wired in relation to one another. Actually, this is a misnomer ... Actually, I learned this by accident. I asked someone from the DiMarzio Pickup Company to take a look at my website. They thought I explained humbuckers pretty well except they wanted to know why (at the time) the graphic showed one coil with clockwise winding and the other coil with counter-clockwise winding. I said well the 2 coils are reverse wound, correct? They said (as far as they knew) they manufacture ALL their humbuckers with both coils wound in the same direction. Read the first section on my website to see what "reverse wired" really means. |
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Post by ChrisK on Apr 16, 2006 13:31:59 GMT -5
Wolf,
Yep, If so, it's eminently reversible;
Pickups would have been so much more understandable if the makers included PHASE dots (instantaneous polarity, like transformers) on the coil(s) and magnet POLARITY on the magnet structure. Then, if a particular maker would state the general (hopefully consistent) PHASING used throughout their product line, all we would need to remember is the relative phasing of a particular vendor.
If we want to combine two coils for hum reduction, first ensure (modify) that they have OPPOSITE magnetic POLARITY, and then wire for consistent PHASING.
Worrying about phasing before magnet polarity is inside out.
Done is.
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Post by UnklMickey on Apr 17, 2006 10:55:43 GMT -5
The windings of the 2 coils in a humbucker actually go in the same direction. Please visit my website page here: www.1728.com/guitar1a.htmand start reading at the part that says ... The other requirement for a humbucking pickup is that the coils are reverse wired in relation to one another. Actually, this is a misnomer ... sound confusing?, well it should. but it aint my fault. Wolf, those DiMarzios you're so fond of, AREN"T reverse wound, just reverse connected. the finish ends of the coils are connected together. on some other humbuckers, the finish of one coil is connected to the start of the other. but one coil is cw, and the other is ccw. so as far as hum is concerned they are OoP. but one coil has a north magnet and the other has a south, so as far as string sensing they are in phase. more than one way to skin a ........ so the difference in whether a coil is reverse wound, or reverse connected, in a HB, further complicates an already confusing issue! i think Falke and ChrisK are on the right track. concern yourself with magnetic polarity FIRST. then figure out which connection direction gives you subtraction in hum -- to determine the correct phase for string sensing. it would be practical to make a test-bed for pickup polarity with a barrier strip, a DPDT, and a jack. using a pickup of known polarity, you would be able to determine the relative hum polarity of the connections by flipping the switch. for SC pickups of the same magnetic polarity, you want the hum to be maximum for an in-phase connection. for SC pickups of opposite magnetic polarity, you want the hum to be minimum for an in-phase connection. for a HB, you obviously want minimum hum, for an in-phase connection. for storage, it won't hurt to have the pickups stuck to each other 1, but it might not be a good idea to have them in a metal box 2. unk EDIT: 1 you might want to separate the pups with a sheet of paper to prevent scratching 2 an old wives' tale says, if magnets are stored in contact with magnets, it weakens them. i'll neither confirm, nor contradict. |
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Post by wolf on Apr 17, 2006 15:17:31 GMT -5
unklmickey
I was quite aware that DiMarzio humbuckers coils were not reverse wound - just reverse connected. My mistake was in assuming that all pickup companies construct humbuckers similarly.
Do you know which companies manufacture humbuckers that have 1 clockwise and 1 counter-clockwise coil? (Just curious).
To confuse the issue even further, I'm sure you have read that to eliminate hum, a humbucker's coils are connected out of phase to cancel the hum, which is another misnomer.
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Post by UnklMickey on Apr 17, 2006 15:48:03 GMT -5
Tom Anderson is one that actually has reverse wound coils.
if you have a chart that shows start and finish colours, look for a series link that has a start connected to a finish. that will indicated opposite winding directions.
"To confuse the issue even further, I'm sure you have read that to eliminate hum, a humbucker's coils are connected out of phase to cancel the hum, which is another misnomer."
i don't know if i'd call that a misnomer, or just poor wording.
in relationship to the windings, they are OoP.
but in relationship to the total system of winding AND magnet polarities, they are in-phase.
unk
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Post by ChrisK on Apr 17, 2006 18:34:28 GMT -5
If I had a coil that was mounted on a PCB and wound in a particular hand, I'd be concerned due to symmetry. Reversing the mounting wouldn't help, you would indeed need coils wound in opposite hand (and magnet polarity) to achieve hum canceling.
However, due to the modern magic of "free range" pickup wiring leads, I'm more than unconvinced that "handiness" means anything more than amalgamated boopky. Start and finish, and top and bottom are moot. First justify the magnet polarity and then just reverse the wires as needed.
Horse, dead, beaten, is.
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Post by Runewalker on Apr 17, 2006 22:29:57 GMT -5
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This goes to the heart of modding one's guitar in search of usable tones. If we're just poking around in the dark, then we'll never find what we're after, right? Let's see if we can't nail this puppy down and get it right. I'd rather eat crow now, if I'm wrong, than continue designing circuits based on faulty knowledge.
