[time-nuts] 10 MHz 'failover' switch?
hmurray at megapathdsl.net
Thu Jul 26 18:05:17 EDT 2018
kb8tq at n1k.org said:
> One interesting subtlety making something like this:
> What if the two inputs arenât quite on the same frequency? Purely as an
> example, say they are 1 Hz off from each other. If you have 60 db of
> isolation in your âswitchâ you get a 1 Hz offset spur that is 60 db down.
> Even something much further down is plenty to mess up the ADEV of the
Has anybody built a microprocessor controlled PLL to handle this case? If you
have the microprocessor and DAC, watching a second input and switching in
software doesn't seem like a big step.
Can I put two switches in series? The is-it-working logic has to be look
before the first switch, but the first switch is on-off rather than A-B. It
can be in a separate package placed to minimize feed-through.
These are my opinions. I hate spam.
More information about the time-nuts