If i want to use an enclosure that is not made from metal for an analog, unbalanced, maybe higher impedance circuit, is it sufficiant to glue a layer of aluminium foil to the inside of the box? (and ground it, of course)
I know it will work to a degree, i´m just not sure if it will work any less than a normal steel sheet enclosure.
Depends on the frequency spectrum that you are shielding against.
Foil, copper, and conductive paints provide "reflective" shielding for the upper band RF frequencies (>10KHz). You also need "absorptive" shielding... like mu-metal or thick steel for the low frequency (<10KHz) electro-magnetic fields like A.C. transformers.
Try to get cheap 3M ultraperm 80 sheet, if you found < $8 A4 Sheet from mill. surplus provider. Beware with overpriced sheets or cutted sheets on ebay or "esoterics" alloys advertising.
Foil, copper & space got good results also.
Why I said ultraperm & mill. surplus ? because I ever found ultraperm cheaper than copper and others alloys, on a RAF spare parts sellers. I think, this surplus/spare providers maybe are more common in U.S. Or maybe 3M USA sell on retail.
Make a double sided with one sheet, facing the two adhesive sides. The effectiveness is better and very high with a thin and high malleability. Be careful, the edges can cut like a knife.
I have noticed that when i breadboard a prototype without an enclosure it picks up hum and buzzing noise.
As soon as it´s in a steel enclosure hum and noise is gone.
That is the effect i am after.
Basically i am thinking about building some circuits in nice wooden boxes.
sure, that idea comes to mind. I was just curious if this is necesary or if a layer of aluminium will be just as good for the task.
(And, instead of making my own experimants i use this forum to see what you have to say... thank you!)