I bought a used 10Mhz Rubidium oscillator from eBay. The unit is “untested” but it comes with a money back warranty. Do you have access to a calibrated scope or frequency counter so that I can check if the unit is working properly? Thanks!
I have an oscilloscope with a terribly out-of-date calibrated frequency counter. Handy thing is it’s pretty stable once it warms up but it’d only be really useful for showing stability of another oscillator, not the accuracy.
Unfortunately I haven’t been able to build my own 10MHz standards which, if calibrated, could be used to confirm that one.
This looks interesting, maybe it could help with your osc. project? http://www.ebay.com/itm/221769369180
I’m not sure you really need a calibrated instrument to verify the operation of the Rb osc. Even a high quality calibrated instrument is going to have long term stability much lower than Rubidium. Basically if it indicates lock-up and outputs 10MHz within your ability to measure it, you should be able to trust it. There’s not much to go wrong in the physics package that will cause it to lock but output a slightly incorrect frequency.
A “worn out” tube would cause a failure to lock and frequency hunting. Keep in mind these surplus Rb oscillators are mostly out of cellular base stations, and have been running 24/7 for many years. They have a limited lifetime and may be worn out or have limited life remaining. I would not run one 24/7; they don’t really need time to warm up and stabilize after they lock.
To really verify that it’s within spec, you need something more stable than the Rb is supposed to be, preferably by at least an order of magnitude, and then take some long term measurements with a good interval counter. A good Cs standard might be good enough. GPS is probably good enough over the long term, which is relatively obtainable, but if you go to acquire a GPSDO you no longer really need the Rb, do you 
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Does VHS-ARC have an HF antenna set up? You could zero-beat it against CHU or WWV.