First pickup

Pickups, Diy Electronics, Stompboxes, Guitar wiring...
Bent
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Re: First pickup

Post by Bent »

I couldn't care less if its AC/DC or whatever :-) All I care for is to control the darn speed. And man..are you guys ever a huge source of information to a greenhorn when it comes to electronics!! Thank you all for great advice.
The one I favor the most is Allan's suggestion of a router variable speed control. Maybe even the light dimmer switch would work. What I need to do is make sure it can handle the wattage? or the amps? See how dense I am with these things?
Hehe in the meantime what I did was a Red Green solution. I drilled and tapped a hole down thru the pedal and mounted a screw there so I can tramp the pedal down and it won't go beyond the first speed which is exactly 310RPM
http://benrom.com/
21 BenRom pedal steel guitars, a Nash 112 and a 1967 TOS Milling machine with many cutters making one hell of a mess on the floor.
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Georg
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Re: First pickup

Post by Georg »

So, you don't need a counter anymore, you can check number of windings with a stopwatch..? Or, set an alarm clock for 9153 windings, and let it cut the power when it goes off..? :P
Perfect! :lol:
Allan
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Re: First pickup

Post by Allan »

Bent, putting a screw through the pedal is brilliant! You still need a controlled start and a gradual speed up and I would say go for the router controller but a simple screw through the pedal as a 'maximum speed stop' is totally elegant.

Now, a question if I may. Did you wind the coil straight around the magnets or did you make a core piece? I don't know what practical difference it would make but I just feel that you may have a hotter pickup without having a core. I am thinking that with the coil being closer to the magnets...??? See where I am going? I wondered if you had any feeling for that yet.

Allan.....
Only nuts eat squirrels.
Keep yer tools sharp! That way you can use more of your strength guiding them AWAY from your body rather than forcing the cut!!!
Bent
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Re: First pickup

Post by Bent »

Allan,
I agree with your router control. I did the screw stop thing just so the unit is workable until I get the control. This first pickup, I had to sit there and be careful not to let the foot press too hard. The result of that was my foot wanted to cramp up and whatnot. I can live with the sudden start for now.

Yes, this one, I wound the wire right around the magnets. Maybe Georg or anyone can tell me if this makes for more hum? In which case I won't do it again. I was in doubt after seeing Mac's procedure of making an actual wood piece. But for this first one, I did it the way I thought most pickups were done.
I would actually really like to try what Mac does.

I am totally green about what constitutes a hot or not so hot pickup.Hopefully this will change when Georg comes and is able to pound some of his knowledge into my head.(By the way Georg, that alarm clock thing was brilliant :idea: You just have to inform me how to wire up the damn thing...like set the alarm to go off at
9:15:30..would this be Am or PM? :? )

All I know for now is that my first attempt was a success and it gave me the initiative to keep winding :-)
http://benrom.com/
21 BenRom pedal steel guitars, a Nash 112 and a 1967 TOS Milling machine with many cutters making one hell of a mess on the floor.
Steve W
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Re: First pickup

Post by Steve W »

I have read that there should be some amount of insulation around the magnets. The reason is that the magnets can attract rust over time and pull that down into the coil. The rust eats the insulation on the wire and can eventually short out the pickup. Some builders will put or dunk the bobbin in laqcuer and use it as an insulator or the magnets before winding. Others will use electrical tape or even material tape around the magnets to help this issue. P-90's use a 1/4 piece of platice that is drilled out for the adjustable screws. It sounds like the added distance of the coil to the magnets or pole pieces is a tone issue but not much or not as much as bobbin height or coil width.

When putting the two pieces of platic together with the magnets you can use two pieces of wood as wedges that hold the whole thing to gether in the right position as the glue dries. I have read that super glue is not a bad choice.

When you put the pickup in you could try a little experiment. See how it sounds then pull it out and add a steel plate on the bottom. The plate will be a bit smaller that the bottom piece. This steel plate changes the tone as it redirects the magnet and suposedly changes things. Sho bud permanents have this as well as the bridge pickup on telecasters.

Anyone have an idea of why single coil pickup makers don't use shielded pickups?

Potting? Paint lacquer on the windings every minute or so. It won't cause the issues of wax potting and you don't need the special tools........or so I've read. I should be winding next week. I'm going for a metal topped, single blade, dual bar magnet to blade, low impedance larger wire pickup. Who knows how it will turn out, but what the heck.
Bent
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Re: First pickup

Post by Bent »

Steve, thanks a lot for the great info..Just in time, as I am about to glue together pup #2 after dinner and start winding. I'll take your advice re the tape on the magnets.
As for waxing or, like you say, lacquering the coil, tell me what the actual benefit is? I think Georg said it is to prevent microphoning. How can I tell if my pup is microphoning?
Edited to add: How do you go about shielding the pickup?
http://benrom.com/
21 BenRom pedal steel guitars, a Nash 112 and a 1967 TOS Milling machine with many cutters making one hell of a mess on the floor.
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Georg
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Re: First pickup

Post by Georg »

Bent wrote:How can I tell if my pup is microphoning?
Place it on a very soft surface, a pillow or something, and knock on it with your knuckles. The knocking-sound you'll hear through the amp, is that of a micro-phonic PU.
It's caused by the coil-windings vibrating relative to other windings and to the magnet(s), which ideally they shouldn't do at all. Hot wax penetrating into the coil and then hardening, will minimize coil vibration and thereby the micro-phonic effect.

Micro-phonic PUs are more likely to pick up vibrations and noise through the instrument-body, so once your wound PUs are well tested for all other parameters, a good waxing will do them good.
Just make sure there are no materials in there that can't take the heat needed for deep wax-penetration. Regular (cheap) el-tape will tend to melt, so a thin layer of newspaper around the magnets is better than tape in that respect.

One added advantage with using wax is that it can be undone (reheated) and the coil unwound and repaired if necessary. Don't have that option with lacquer.
Steve W
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Re: First pickup

Post by Steve W »

It isn't easy and some even think impossible to actually completely shield a pickup because of how the picup is exposed on the guitar and how the wires and pots are exposed. Each item can pic up this stuff. Do a search on shielding for some details as I am no expert. But in general pickups and wires and guitar cavities can be covered in metals such as copper to create a barrier that stops the junk from entering the pickup. A metal cover over the pickup is one way but it has to have a ground wire from that cover to the guitar. Shielded pickup wires help from the pickup to the other electronics. P-90's tend to have that.

Bigsbys have aluminum covers and the fit of the pickup is tight to the housing.

I'm using an aluminum top which will have a ground wire underneath that will then ground to copper tape wrapped around the coil after the winding and that gets grounded. But I'm going to see how the pickup sounds before going through the tape part. The aluminum top is good for sheilding but it also looks kind of cool.
Bent
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Re: First pickup

Post by Bent »

Steve, sounds like "sound" advice. I do have unacceptable hum in my pickups. Here is what I have tried so far without any noticeable difference: Shielding wires and pickup with aluminum foil and grounding it. Also, running a wire to extra ground.
http://benrom.com/
21 BenRom pedal steel guitars, a Nash 112 and a 1967 TOS Milling machine with many cutters making one hell of a mess on the floor.
Allan
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Re: First pickup

Post by Allan »

You can get really thin, really flexible copper sheet (foil really) from 'OnLine Metals' (probably from the others too). That's what I use to screen all the cavities in the guitars that I build.
I cut one piece for the bottom of the cavity and another for the sides. The side piece has a tab that turns over onto the face of the wood and is placed so that a screw holding the plastic work goes through it. The inside face of the plastic is also lined with copper. All of that material is glued in place. (contact cement) The different pieces inside the body are linked with a simple solder bridge and then the whole thing is connected to the common ground point which is generally the back of one of the pots. Be sure that the bridge or the tail piece (not both) is also connected to that same point. Single coil PU's are noisy but it is obviously possible to bring that down to an acceptable level.
I have used the copper sheet technique on my Strats too and made a lot of difference to the noise level. They were not too bad before but around strip lighting for example they could be a bit buzzy. The copper made a lot of difference in that situation.

Allan.....
Only nuts eat squirrels.
Keep yer tools sharp! That way you can use more of your strength guiding them AWAY from your body rather than forcing the cut!!!
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