[time-nuts] Rb Standards C-fields
Bob Stewart
bob at evoria.net
Tue Aug 22 05:50:27 UTC 2023
Is there someplace I could get some practical information about C-fields in Rb standards? I'm not looking for the physics of how they work. What I need is on the practical side. This relates to the AT&T RFG-RB unit I bought. Looking at the components, I don't see any obvious voltage references. It has a couple of power supply chips, but nothing better than an LM-340T-5 or whatever it was. And the C-field adjustment is a 10-turn 5K pot. Â
My bottom line question is this: Would it would make any real difference to the stability of the 10MHz output if I were to add an external voltage reference chip, such as an ADR4550A (or B or C) and a 25-turn pot, or even a DAC1220-E and a dsPIC33 to run it? I'm assuming the center C-field voltage is 2.5V. Given all the electronics in the thing, I'm tempted to just pull both boards out and make a new board to support the Rb oscillator with just the features I need. But if the thing is already near the limits of the Rb oscillator there's no point. It contains an Efratom 102100-003, for which I can't find any information.
Bob
More information about the Time-nuts_lists.febo.com
mailing list