Charles, >>When using a spectrum analyzer to examine the output of a frequency >>standard, what are the minimum specification needed? Bandwidth, >>resolution, sensitivity, etc?
> It very much depends on what you hope to see with it. That said, > virtually no SA will do anything useful in this application without a > fair amount of preprocessing. > . . . > I am all for having one or several SAs around the lab, but I fear > that an SA may not be very useful for the particular tasks you are > hoping it will perform. Being new to this, I don't actually know what I need to see with it. However, I see charts that show the "spurs" on the output of an oscillator. I assume that I will want to do similar tasks. As I understand it, those are the main problem when multiplying the frequency by very much because they get multiplied as well. Thus, one of the differences between a "good" OCXO and a "bad" OCXO. > Pay attention to ergonomics -- suffering with an SA that doesn't > think like you do will drive you crazy. For example, I prefer > HP/Agilent SAs over Tek SAs because the HPs allow you to specify a > start and stop frequency *or* a center frequency and span, while the > Teks only allow you to specify a center frequency and span. As an example, I currently have a broken MTI 260 which I am repairing. I currently have it cleanly disassembled so that it can be reassembled with no damage. I know what needs to be done to fix it (at least the first pass) and am waiting on a tool that I need. But, if I succeed in repairing it, what test equipment do I need to determine the quality of output? I can measure frequency to a point (7 digits, uncalibrated - 8 once I have a frequency standard). That is not enough to determine very small deviations from 10Mhz, but it will tell me that I have a sine wave at approximately the correct frequency. The last one I (sort of) repaired, gave me a sine wave but with a duty cycle that wasn't exactly 50-50. So there must be some distortion present. Not surprising in that case because of the hacking that I did. However, I understand that the quality of the OCXOs can vary widely. What tools do I need to determine the quality of output? I assumed that a spectrum analyzer would be a first step - to look for large spurs, overtones and consistent noise (e.g. 120 kHz components) at unusual frequencies. Even jitter and phase noise should show up that way - at least with sufficient resolution, which might be unrealistic. Mike _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.