Capacitor replacement for old Pyramid?

[bill0287]

I am going to replace some capacitors in my Marvel 35 amp (mentioned here in other posts). I pulled one of the caps out and it says it's a Pyramid 85 TOC .02uf 200V radial. It also says "Outside Foil" on it. It's orange in color and is covered with a sticky good or wax (as are all the others like it)

The only thing I have on-hand is a Vishay .022uf 400V radial like this one. But it's about 1/10 the physical size of the Pyramid.

What would be a proper replacement capacitor type for this?

(I am replacing them just as an exercise)

[loudthud]

The Vishay caps should be fine. Be careful not to touch any part of the body of the cap with your hot soldering iron. If you can find a data sheet for the parts you are ordering, it may tell you which end of the cap is connected to the outside foil. As a guess, I would say it's the end with line all the way round the part.

[Mick Bailey]

I've used those caps a lot, both for new builds and as replacements. The line is the connection to the outer foil. All components are now physically much smaller than they were and with capacitors its down to improvements in dielectric materials that means for a given value and voltage the parts can be comparatively tiny.

Out of interest, when I've done restorations on older equipment (for customers who insist on their amp looking 'period'), I've sometimes recreated a cap such as an Astron and hidden a Vishay radial inside. To make the label I use an inkjet printer to print out the graphics onto a brown envelope, then trim it to size, stick it to the new, larger cap body with PVA and dip it in beeswax/paraffin wax mix. Makes for a very pleasing and functional cap that's more in keeping with the original. Some older caps can also be drilled out in the lathe in order to fit a modern radial and capped off with epoxy.