Mark J. Blair wrote: >> oscillator inside a Tbolt then I don't think that a frequency >> discriminator will be sensitive enough, although I might be wrong. > > I got the impression that for "good" OCXOs like the HP 10811 or > (supposedly) the OCXO in my TBolt, the delay line method wouldn't provide > enough sensitivity for measuring close-in phase noise.
Right, the delay line method is a non-starter. > >> Despite what you said, you might want to consider buying an HP 10811 >> oscillator or similar which you could use in a phase detector >> measurement system which is likely to give superior results. > On the 10811 production line, they would use Anzac AMC-123 amplifiers to drive a +17 dBm mixer, and then amplify the IF output with a low noise current amplifier like the Linear LT1028. You can easily homebrew this setup. You will need to have a DC coupled connection to the IF output to make a narrow PLL that drives the EFC of one of the oscillators. You can use a PC based audio spectrum analyzer program to look at the phase noise output. You can break the PLL to get a beat note to calibrate the system. The AMC-123 can also be homebrewed by reading the patent, which is listed on the data sheet. No need at all to get a 3048, etc. Rick Karlquist N6RK _______________________________________________ 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.
