Here is an interesting link to the New Horizons Mission to Pluto radio system design. Note last section describes an OCXO with ADEV = 1E-13 at 1s, and aging rate of <1E-11 per day. http://www.uhf-satcom.com/amateurdsn/Paper-969.pdf I wonder if their spares will show up on eBay? John Stuart, KM6QX Lafayette, CA