#1
When one wants to block out hum and other interference, one technique is shielding the wiring compartment via the back of the pick guard. There are some guards available with conductive foil on the back side just for this reason. Would a copper screen/mesh do the job as well, or would it need to be solid?
#2
well... the whole point is to create a block to stop the interference. and if there is holes in your block, i dont think it would work as well... but i could be wrong.
i assume your asking because you have some copper mesh and you just want to use that. well, i think to be safe just buy some tape (its really quite cheap on ebay)
#3
Quote by Doonan
well... the whole point is to create a block to stop the interference. and if there is holes in your block, i dont think it would work as well... but i could be wrong.
i assume your asking because you have some copper mesh and you just want to use that. well, i think to be safe just buy some tape (its really quite cheap on ebay)


No, I don't have any and could get either. I'm asking because mesh can be embedded in composite/epoxy laminates much better than a foil can, and that's what I'm making the pickguards from. As for holes, a satellite dish can be half holes as long as they're not over a certain size and far enough apart and it'll still reflect the microwaves. I don't know if such a thing applies to the kind of EMI guitars are subjected to.
#4
Quote by Doonan
well... the whole point is to create a block to stop the interference. and if there is holes in your block, i dont think it would work as well... but i could be wrong.

mesh works just as well as tape. one is done just as much as the other.

honestly im not real clear on wave behavior so i dont know the specifics

TS, you might already know this, but if you are embedding mesh r foil into a pickguard, make sure there is a way to ground the mesh or foil. not grounding a shield makes it useless as a shield.
#5
Quote by Invader Jim
mesh works just as well as tape. one is done just as much as the other.

honestly im not real clear on wave behavior so i dont know the specifics

TS, you might already know this, but if you are embedding mesh r foil into a pickguard, make sure there is a way to ground the mesh or foil. not grounding a shield makes it useless as a shield.


Most excellent, thank you. And the reminder about the grounding strap. The carbon fiber guards are conductive, but the texalium being aluminum impregnated e-glass are not so well. I reckon in both cases to lay the screen down before laminating so its only embedded in the epoxy on the bottom side rather than between the cloth and substrate. Scrape a spot, solder a wire, and it's done.
#7
You can get single sided sticky metal tape made for that. Can't remember the brand (Dunlop?), but I found mine at a guitar center or some place like it. They give you enough tape for cav and guard.
#8
So long as they're holes not slits it's fine. Basically any shielding will work if holes in the shield are still significantly smaller than the wavelengths that you are trying to exclude, and as most of these are in radio wavelengths i.e. big, you're fine. Try to have it grounded all the way round the edge if possible though.
#9
Quote by Invader Jim
never said what they were made of. i assumed plastic. yeah that sounds good. whoever buys these, make sure they know to do that.



Yeah, I realized after that I neglected to mention the material first time, sorry.

And according to the manufacturer, texalium is *more* conductive than carbon fiber, which is already used as shielding in some aerospace applications. Thus, the mesh/tape/whatever is unnecessary. The cloth is woven closely enough that you can't see through it, and when compressed during the lamination the fibers are forced together, making the composite essentially a solid sheet of conductor. When cut, the top and bottom are no longer continuous, but when the screws are put through they are again. Not that it's necessary. One face would be enough.

Thanks for the input folks. If the manufacturer hadn't answered I still could have figured it out with your help.
#10
Quote by lozlovesstrats
So long as they're holes not slits it's fine. Basically any shielding will work if holes in the shield are still significantly smaller than the wavelengths that you are trying to exclude, and as most of these are in radio wavelengths i.e. big, you're fine. Try to have it grounded all the way round the edge if possible though.
Afaik, magnetic fields don't work like regular waves. They are what you're trying to isolate (radio freqencies are too high for a guitar amp to cope with or for a human to hear). Magnetic fields are what causes mains hum.
#11
slits, holes, doesnt matter. radio waves (and all electromagnetic waves) arent little particles moving up and down like you see on a graph. they are bursts of energy. the best way to demonstrate it is open and close your hand at fixed rate.

anyway many op-amps and transistors can operate well into the RF range. all it takes to make an AM wave audible is a single diode. a guitar is pretty good at picking up radio waves as well.

we can indeed hear radio waves coming from audio equipment. try using a PA near a highway with heavy trucker traffic. their CB radios are easily heard through certain amps. we had this problem in my highschool in the music history class. teacher plugged his laptop into a PA to play the music we were studying. truckers constantly drove the road outside the building.