A couple of shielding questions

[adamrobertt]

1.) Does shielding actually do anything? Is it worth it? My current Jazzmaster has a copper shield on the back of the pickguard (Rothstein) but nothing in the cavities. Should I line these with copper foil too?

2.) If I decide to go this route, how do I ground the cavity shielding with the rest of the circuit? Is the little piece of guitar string coming out from the thimble enough if it makes contact with both the copper shield and the copper backing on the pickguard? Thanks!

[Larry Mal]

Well, yes, it obviously does something. You're making a thing called a Faraday cage:

https://en.wikipedia.org/wiki/Faraday_cage" onclick="window.open(this.href);return false;

And it won't help with 60 cycle hum, so be aware of that. However, there's tons of electrical interference in the world today, far more than existed when all these guitars were designed. Shielding is more important than ever, if you ask me.

You'll need continuity to ground for it to be useful. If you line the cavities with copper foil, you'll need to make sure that flows to ground or you've basically added an antenna and added more problems. What I usually do is just make sure some of the copper shielding lays on top of the guitar body, where it will connect with the shielding on the underside of the pickguard, and then you'll check for continuity to ground. Your Jazzmaster grounds to the bridge posts, if I recall correctly, so you'll take an multimeter and test various components and shielding with one of the probes and the bridge post with the other, and if you have continuity, then you have proper shielding.

[windmill]

Have listen to what Dave says

from about 5 minutes in.

https://www.youtube.com/watch?v=Qp-zFLylafE

HTH

[sears]

He's soldering wires from cavity to cavity but with a mechanical connection, like Larry says with the pickguard or plate touching the cavity shielding it should all be grounded. Provided your pickguard is shielded.

[Larry Mal]

Right, he says in the video that while the cavities were painted with conductive paint, they were connected- there wasn't continuity- so the electrical noise wouldn't have gone to ground. In other words, like I say, it would have acted like an antenna more than any kind of help.

I was going to say that electricity takes the path of least resistance, but after claiming last night that Jazzmaster pickups were attached to the pick guard, I'm doing some basic research on what I say for a while. So it turns out that it isn't true that electricity takes the path of least resistance:

http://ecmweb.com/content/path-least-resistance" onclick="window.open(this.href);return false;

But regardless, when shielding, you are providing electricity with a path to ground, and safely out of the way of your other electrical components, ideally. If that pathway doesn't connect all the way to ground, like apparently Fender didn't do with that Jaguar bass, then you have accomplished nothing and quite possibly made the problem worse.

This makes it seem more complicated than it is, though. So you have a Rothstein guitars copper shield (I have one also) and that faces down into the cavities when it is screwed on, and that copper shield in your pick guard does (or at least should) run to ground. It would be worth checking.

If you put a bunch of copper shielding in the cavities, it'll face up, and like I say if you have some that lays on top of the body of the guitar where it connects to the copper shielding on the pick guard, that's going to provide continuity to ground. I've been known to add another wire from ground to the bottom of the cavity's shielding, but you don't likely need to do that.

But it doesn't matter how you do it, the copper tape has a conductive adhesive on the bottom of it, or it wouldn't work, so it's really not all that hard to provide continuity.