Richard Clark wrote in message . ..

If you waited a year instead of 3 months, the Bird that was out of
whack would still be out of whack, but probably at the same level.
You could say pretty much the same for 20 years later (barring smoke
curling up at hot connectors). Repeatability is accurate only when
you've calibrated it.


Then it sounds like you could re-calibrate after 3 months, and not
have to worry about it for a while.


Slick