Yeah, it gets a bit heated. Since you have the data sheets and all, could you spare us a bit of work and summarize, for each OCXO: - What EFC and power voltages it needs. (Using an input voltage lower than your own supply rail seems odd.) - What EFC voltage stability (uV per day or whatever) is needed to match the oscillator stability (ppb per day). - And what RFC voltage tempco (uV/C) is required to match the oscillator tempco (ppb/C).
Obviously, we want to do better than just *matching* the OCXO specs, because that would degrade performance noticably, but it's a good number for comparison. And doing more than 10x better is probably a waste. On particular, if the +/-10V EFC oscillator is an older model, we might not need the same specs on the level-shifter as on the 0V-based amplifiers. I'd also be curious what the bandwidth of the Fury discipline loop is, approximately. A simple passive low-pass filter can cut off higher frequencies without causing problems, but phase shift at too low a frequency can cause oscillation. That determines the bandwidth over which the buffer amplifiers have to be quiet. If the frequencies are low enough, it might be worth using a chopper-stabilized "zero-drift" amplifier. They have some high frequency hash in their output, but it can be filtered out. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
