On 12/31/13 8:07 AM, Anders Wallin wrote:
Could the remaining -60 dBc spurs at +/- 50 kHz be due to my 10MHz clock
source, an Agilent 33120A?
Yes the spurs could be from your source. that's a function generator/ARB
and spectral purity isn't one of the big design criteria for that kind
of device.
The spec sheet says spurious non-harmonic signals are supposed to be
down -65dBc + 6dB/octave above 1 MHz.
http://cp.literature.agilent.com/litweb/pdf/5968-0125EN.pdf
I don't know all the gory details of how the 33120 works inside (though
I've got 3 or 4 of them in my lab at work), but in general, it has a DDS
running at 40MHz that clocks samples out of a waveform table to a 12 bit
DAC. The output from the DAC is run through some analog circuitry for
doing AM and setting offsets and levels.
http://cp.literature.agilent.com/litweb/pdf/33120-90017.pdf
50 kHz is somewhat suspicious.. do you have any switching power supplies
at that rate around? It doesn't take much noise added to a sine wave
running into a comparator to create spurs. I've had that problem with
leakage of a 66MHz processor clock into a 50 MHz sampling clock.
_______________________________________________
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.
