[time-nuts] Re: Why do have OCXO a Vref output? (was: help reviving Trimble UCCM-LPS GPSDO)

[ed breya]

I forgot to mention that the TCZD regulators are affected by the power 
supply too, depending on the rest of the circuit. I think they typically 
had a two-stage deal, with a regular Zener to make a higher voltage, and 
provide a fairly stable supply to operate the reference regulator, but 
of course, not perfectly. This was in the days of 20-28 V OCXO 
operation, where there's plenty of headroom. At lower voltages like 12 
and below, this becomes trickier, so some designs may still have used a 
TCZD, but only the one stage, and relied on the main supply to be well 
regulated.

Ed