What caps to order?

[Nick_the_'Nole]

C-D caps are good quality, but there's really no reason to use them over the much less expensive Nichicons and such. The difference between 4.7uf and 5uf, or 47uf and 50uf, is really just one of notation... the values on old caps were usually rounded off to whole numbers, while modern ones are standardized onto the same system of values that resistors use (which is a geometrical progression).

Notice the tolerances on those C-D caps... -10%/+75%, meaning the actual value of the 5uf cap could be anywhere between 4.5uf and 8.75uf. In standard capacitor values, it would probably be classified as a 5.6uf cap, perhaps even 6.8uf.

As far as grades of capacitors, computer grade is better quality, but completely overkill for use in radios and such. A modern 'general purpose' cap will be better than even a high-quality, low-noise cap from 50 years ago. I personally go with 105C low-impedance caps wherever possible, though, since they usually don't cost appreciably more than the standard grade caps anyway.