I find myself asking that same question sometimes :-) I guess the simple answer is "because it could be done". For voice SSB, a few 10's of Hz ether way is hardly detectable, and I don't plan to do any digital work with the rig that would require that kind of precession, so I guess it goes back to my days working in an instrumentation standards lab in the '80's where precision was everything and took a lot of effort and equipment to achieve what a few dollars can do today. It's just fun and so satisfying to be able to do it now at home :-) . 73 - Rick - N3FJZ