[time-nuts] About HP10544A
scifiscifi at sci.fi
Sat Mar 7 21:18:33 UTC 2009
> New 10544A's have a somewhat cleaner output than that.
> Perhaps something is wrong with the emitter follower.
Sorry I forgot to say that the oscilloscope picture was taken directly
from HP10544A output, without emitter follower but with 1:1 probe,
output terminated with 1 kohm. resistor. With spectrum analyzer the
emitter follower is necessary due to 50 ohm. input impedance of the
Datasheet of HP10544A claims that harmonics should be more than 25 dB
down. Doesn't look like they are.
Here's a spectrum measured from OCXO which is used in the Thunderbolt.
I'm not an crystal oscillator guru but I think that this is just what an
xtal oscillator output should be:
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