[Elecraft] Differences between disc ceramic and blue plastic caps?

[Don Wilhelm]

Doug,

Component markings have changed a lot over the years.  I would suggest that
you refer to the information in the ARRL Handbook on component markings for
an update on the various markings that are in current (and older) use.

Yes, a capacitor marked '470' is a 47 pf capacitor.  The little blue (or
yellow) ones will do just fine.  The old disc ceramics with the black mark
on the top are NPO type, which has the same thermal characteristics as the
'C0G' type.

It is not good practice to try to identify a component by its color - that
could change at the whim of the manufacturer, learning the current markings
for components is the only way I know to be certain about the designations.

73,
Don W3FPR

> -----Original Message-----
>
> I'm went looking for a 47pf cap for C73.  Naturally, (probably because
> I'm an old-timer, ya know - kits from Knight-Kit, Johnson, WRL, Ameco,
> not to mention the Benton Harbor stuff) I was looking for a disc ceramic
> cap marked 47 with a black mark on the top.  Not finding any, I looked
> through the parts list for the rf board where it indicated in might also
> be marked 470 and be one of those little blue plastic caps. Just so I'm
> sure before I solder these puppies in, C73, C20, C24, and C203 are OK as
> little blue plastic caps marked 470, correct?
>