Shielding Question

[Devo]

Hi,

I have a choice between some copper foil ~0.0007mm (same as aluminium foil but copper I guess) and some thicker sticky-back stuff to shield the the pickup cavities and control cavity area on two of my guitars.

Is the foil thick enough to do the job? or do I need something thicker like the sticky-back stuff? What is the physics behind it? Will a thicker copper sheet give me more shielding... my gut feeling tells me the thickness isnt important but I want to make sure.

Thanks

Steve

[lovekraft]

The shielding really only needs to be a few hundred microns thick (if I remember my physics right). If the thinner foil is not too flimsy to work with, it should work without any issues.

[Dugz Ink]

The only time I've seen (heard) a need for "heavy" shielding was in situations with extremely sensitive equipment in high RFI/EMI areas... but thoses cases usually involved sattelite receivers that had been mounted in the same room as broadcast exciters and transmitters. In those situations, the unit had to be in a completely sealed case that was made of aluminum alloy that was about 1/16" thick.

In other words, you probably will not be playing your guitar in an area where you have to worry about the thickness of your shielding... unless you just happen to have an AM tranmitter in your house.

Having good connections is much more important.

D~s

[ansil]

YOU CAN GET THE LEAD THEY USE IN XRAY ROOMS REALLY CHEAP CALL A COUPLE OF DOCTORS THAT HAVE IN HOUSE XRAY ROOMS AND ASK WHO BUILT THE ROOMS I GOT THE EXCESS ROLL FROM THE CONSTRUCTION COMPANY FOR FREE. AND ITS MASSIVLY THICK BUT IT IS ALSO 10X BETTER IMHO.... sorry darn capslock

[rockthe40]

ive only shielded one guitar and i just doubled-up normal aluminum foil using that adhesive spray stuff to get it in there and it works perfectly. i just bought the spray and jacked my moms foil lol

[Devo]

I figure there should be no problem with using aluminium foil probably the best option cause of its price. I cant remember my physics at all though.

theres got to be someone out there who can tell us. I figure any thin conductive material (cheapest and easiest being foil metal eg aluminium foil) should do it so long as its connected (eventually) to the ground lug on your ouput jack.

Lead would be good too.. dont know if its a better conductor then copper or aluminium.. but if you were getting serious x-ray or B-particle interference then lead would definatly be the way to go .

[lovekraft]

Lead has other problems, like weight and high toxicity, but you can use just about anything that's conductive. I've even seen that cheesy "magnetic" paint that Krylon sells used to shield the cavities - evidently it has enough iron (?) in it to be fairly effective if you use a couple of coats.

[KeithHowell]

To shield from RF interference you just need to make sure the "holes" in the material you are using are smaller than the wavelength of the interference. To give you an idea: the wave length of microwaves around 4 Giga Herz is about 60mm, 50Hz mains hum is many kilometres so any foil or even fine mesh will work.

If fact I have worked in rooms where they are shielded with mesh of about 20mm gaps (shielding test equipment from navy radar).

Keith

[Devo]

Great!!

Thanks Keith, i was hopeing for an answer like that.

excellent!

steve