shaggy said:
Is this stuff be the same as used making in film capacitors? What prevents the 'bare' aluminum layer from oxidising? I wonder is there a gold ('space blanket') version with the same range of thicknesses. So many questions(!)
It occurred to me you could probably remove the aluminium layer around a 1" spot to make a center-terminated skin. I'm sure it's been tried.
Bare Aluminium always oxidises. The Oxide layer protects the rest unless the layer is too thin. The layer in film capacitors is so thin it will oxidise perceptibly before your eyes and bits will fall off a little later.
Read Les Watts (ex Shure) on Gold sputtered film in the MicBuilders thread. You have to sputter while the film is TENSIONED correctly else the layer will crack when you tension it. That's why space blanket Gold film isn't much good.
If you are making EVIL Neumann style centre terminated capsules, you have a problem
Calrec's heritage is from AKG via Clem's (my mike mentor) friendship with Bernhard Weingartner who did C12 for AKG. Hence we sneer at the Neumann centre terminated rubbish ;D