[time-nuts] HP 8663A: option 003

[Matt Huszagh]

HP 8663A option 003 gives guaranteed/specified SSB performance for the
640 MHz output. What exactly does this mean? Are there hardware
differences in the reference section of the 003 units in comparison with
non-003 units? Or, was the hardware the same and HP simply categorized
them according to measured SSB performance? If it's the latter, what
implications does this have for buying 003 or non-003 units now? I think
I remember reading somewhere on this list that 10811A SSB
categorizations don't matter much after this amount of aging. Maybe the
same thing applies here?

Thanks
Matt