And number three also locks without problem. This one is from 2001 and has some 3.9 years of run time.
Thanks for the document, i've got a lot of reading to do. When i search for "life" in the pdf, there are a number of parameters mentioned:
OCXO Control Voltage. Typical 2-4 VDC during lifetime. My values are 3.2, 2.8 and 3.0 after running for ~2 hours. So well within spec.
DAC Gain: 1.4 to 256, where 256 is end of useful life. My values are 3.88, 4.27 and 3.08. It's 256/N, where N varies from 180 to 0. So an N of 66, 60 and 83. "On" hours: 33540, 31071 and 34406. That does not add up, the one with the longest hours has the highest value. It would add up if N goes up, instead of down to 0. But you are right, this is for a different instrument. Maybe the value goes up here? I will see where it goes in the future.
Think the parameter for "Signal Variance" is Signal Deviation, or Deviation. 120-150 for a normal tube and 70-90 for a high performance tube it says in the doc.
I've got: 145, 141 and 147. But 120-150 is for the CsIII. You are mentioning 200/225, that's better
And also the values went down during the hours they ran. E.g. from 200 after lock to 147. So it could well be going down further after more "on" time.
I found the loggin function in the monitor program. For number three i've made a logging for the whole time. You see the Ion Pump go up to 70uA, going down in the ~25 minutes it takes time to lock. When it locks the OCXO jumps to the control voltage and then slowly creeps down again (further warm up of the oven).
Unfortunately there are no such details in the PRS45 manual. And i did not find a manual for the PRS45A at all.
Some pictures:
The alarm is because there is only one power supply connection used (Fuse A open). No other alarms.
Yes it was a score. I payed peanuts for all three...