In message , Joerg
writes
When you look at older (pre-PLL) VHF communication gear of the more
professional kind they didn't use 5th or higher overtones but employed
frequency multiplier stages. For good reason, one being the offset you
had mentioned. I'd never run a crystal on its umpteenth harmonic and
always designed in multiplier stages like the radio folks did. With
today's cheap logic chips that doesn't even cost much in extra parts.
Often cheaper to multiply up than buy an expensive 5th overtone that was
difficult to pull onto frequency and fussy to set up.
The exception would be current and size saving for some portables.
--
dd
|