How Much did the OCXO Drift Since the Last Calibration? 

If you have issues with the 1992 buttons failing check out my video on replacing them, I have a link in its description to where I got the switches from.

Whoho! Another video from Kerry :D

Great Info thank you, sir.

Thanks for the Video. You may obtain better accuracy by feeding the counter's 10 Mhz oscillator output into channel 1 of an oscilloscope, with the output of the rubidium standard fed into channel two. Use the *fine* adjustment to null any drift between the two traces.

I recently bought an EIP 545A from Ebay that was last calibrated 15 years ago. I compared it to a GPSDO and it was about 1Hz out. Not too bad.

Hi Kerry. On your Racal counter, if you move up to max resolution and hold the up arrow for 2 seconds you will get a further increase in resolution!

under that other screw is the fine adjustment knob to get rid of the 0.03hz offset

Hey I am close to a time-nut with 2 HP 53131A US Options, 2 Racal Dana US Options too and one old Voltcraft with US Option also. U really need to warm up the US Option OCXOs for 3 days and more. The Rubidium needs more than a week to be stable. I have a the simple chinese FE- 5680A, an unknown symetricon and a few GPS nomal. 1rst rule, never shut down the devices. Thats why most of the devices has no "real" power switch, just a stand by. But what I've seen, you calibrated your Racal Dana with the coars screw only. There's a Fine tune trimmer under the 2nd Screw. With your Rubidium it is easy to calibrate your Racal Dana up to zero. Your Racal Dana has not the resulution to overbid the internal OCXO. Most cheap OCXO or $50 Morion Double Oven CXOs has more accuracy than your Racal Dana can count.

Ummm... adjusting it isn't calibration... calibration is way different from simple checking against a reference.