Question on Shielding

[dundizzle]

Wiring my new pups in a couple days, and just picked up some conductive-adhesive copper tape for shielding the control cavity / pickguard of my strat. Working from this diagram. I have done some reading already, and know you have to create a Faraday cage by having the foil extend slightly onto the body of the guitar, to make contact with the pickguard foil. I have a few questions for the more electrically-inclined:

1. If the top of the pots are touching the copper foil on the pickguard (a ground connection), does this remove the need for running a ground wire between the backs of T1->T2->V?
2. Unless I'm missing something huge, the bare/green wires from the pickups are still soldered to the volume pot, not to the foil?
3. The common ground for the trem claw should be soldered directly to the foil inside the cavity
4. The output jack cavity does not require shielding

Am I mistaken in anything, or missing something obvious here?

Cheers!:beerchug:

 

[Brandenburg]

Re: Question on Shielding

Wiring my new pups in a couple days, and just picked up some conductive-adhesive copper tape for shielding the control cavity / pickguard of my strat. Working from this diagram. I have done some reading already, and know you have to create a Faraday cage by having the foil extend slightly onto the body of the guitar, to make contact with the pickguard foil. I have a few questions for the more electrically-inclined:

1. If the top of the pots are touching the copper foil on the pickguard (a ground connection), does this remove the need for running a ground wire between the backs of T1->T2->V?
2. Unless I'm missing something huge, the bare/green wires from the pickups are still soldered to the volume pot, not to the foil?
3. The common ground for the trem claw should be soldered directly to the foil inside the cavity
4. The output jack cavity does not require shielding

1 i wouldnt trust it but in theory , you are correct.. on my dinky i did this but it was a rear rout.. my pots rely on the foil for grounding and just looked more robust.. BUT on my strat i didnot trust the shielding on the pickguard to give the proper ground connection ( correction.. or so thought.. after looking at the pic i posteds.. loooks like the tone is not grounded to the volume pot via wire but by shielding..
2.. correct.. do not forget to run a wire from the pot to the shielding
3..as long as its connected to a ground it shouldnt matter
4..i shield mine buts that me.. i shield all cavities

REMEMBER .. all cavities that are shielded must be connected electronically.. i take a solid core wire.. strip it.. then solder this from cavity to cavity

for the main star connection on the shield.. i prefer to drill a small hole and use a screw/washer to be my ground point instead of just soldering a wire directly on the shielding.. you can see the 'star point' quite easily from this pic.. dont know if it helps much but i also twisted the two wires from the output jack( i.e. twisted pair)...

another thing I do is use cloth covered wire for most the connections and use solid core wire for grounds to the bridge.. shielding to shield, or for jumpers on switches.. the cloth covered wire totally rules and is pretty thick.. just a breeze to work with

 

[dundizzle]

Re: Question on Shielding

1 i wouldnt trust it but in theory , you are correct.. on my dinky i did this but it was a rear rout.. my pots rely on the foil for grounding and just looked more robust.. BUT on my strat i didnot trust the shielding on the pickguard to give the proper ground connection ( correction.. or so thought.. after looking at the pic i posteds.. loooks like the tone is not grounded to the volume pot via wire but by shielding..
2.. correct.. do not forget to run a wire from the pot to the shielding
3..as long as its connected to a ground it shouldnt matter
4..i shield mine buts that me.. i shield all cavities

REMEMBER .. all cavities that are shielded must be connected electronically.. i take a solid core wire.. strip it.. then solder this from cavity to cavity

for the main star connection on the shield.. i prefer to drill a small hole and use a screw/washer to be my ground point instead of just soldering a wire directly on the shielding.. you can see the 'star point' quite easily from this pic.. dont know if it helps much but i also twisted the two wires from the output jack( i.e. twisted pair)...

Very helpful, and good advice. Thank you!

 

[uOpt]

Re: Question on Shielding

If you have a shielded wire to the output plug there is less need for output plug cavity shielding. But as always, line of sight doesn't go through grounded metal when it hits hot and it'll cause some noise. The tip of the plug is usually exposed.

It doesn't matter whether you connect random stuff to the grounded foil, the back of the pots or any other mass in the guitar. Obviously the foil isn't very robust.

How you establish contact between pieces of mass doesn't matter either. Simply relying on foil-to-pot touch sounds fragile, and there is a risk you touch a hot wire around the pot.

 

[Brandenburg]

Re: Question on Shielding

If you have a shielded wire to the output plug there is less need for output plug cavity shielding. But as always, line of sight doesn't go through grounded metal when it hits hot and it'll cause some noise. The tip of the plug is usually exposed.

It doesn't matter whether you connect random stuff to the grounded foil, the back of the pots or any other mass in the guitar. Obviously the foil isn't very robust.

How you establish contact between pieces of mass doesn't matter either. Simply relying on foil-to-pot touch sounds fragile, and there is a risk you touch a hot wire around the pot.

yes there is... thats why you use a few small strips of electrical tape to prevent such things.. happened on my last project..got no sound and determined that pot 2's lugs where inadvertently grounding.. used a bit of tape and she sprung to life

 

[uOpt]

Re: Question on Shielding

Tape deteriorates over time, though.

 

[Brandenburg]

Re: Question on Shielding

Tape deteriorates over time, though.

true but electrical tape last a pretty long time.. hate it but it is durable.. hmm.. wonder how clear fingernail polish would work..