Hi Grant --
Welcome!
I'd say you're doing OK; most frequency standards don't put a lot of emphasis
on harmonic purity in the specs. Better than 45dB down is pretty good, and not
much TF gear is highly sensitive to harmonics.
I would *not* add a bandpass filter unless you really need to.
Grant wrote:
I tamed the provided switching power supply noise with some L's and
C's, and am now looking at the 10MHz output on a spectrum analyzer.
Here is what I measured:
10MHz +9dbm
20MHz-50dbm
30MHz -37dbm
no obvious higher harmonics
broad noise envelope at 60 75MHz @ -60dbm
10MHz +9dbm
20MHz-50dbm
30MHz -37dbm
no obvious higher harmonics
broad noise envelope at 60 75MHz @ -60dbm peak
Are these results typical or might I have an adjustment or other problem?
I seem to have missed the part where it's explained why anyone cares about
the harmonic
On 08/13/2012 01:24 AM, John Miles wrote:
10MHz +9dbm
20MHz-50dbm
30MHz -37dbm
no obvious higher harmonics
broad noise envelope at 60 75MHz @ -60dbm peak
Are these results typical or might I have an adjustment or other problem?
I seem to have missed the part where it's explained why
john wrote:
Or they [line harmonics] were cancelled by running the TBolt and
spectrum analyzer from the same AC circuit. That's tripped me up before.
Good thought, although probably not the case here. The Tbolt is
supplied from a double conversion UPS with an output that is not
referred
First post as a new owner participant.
I tamed the provided switching power supply noise with some L's and C's,
and am now looking at the 10MHz output on a spectrum analyzer. Here is
what I measured:
10MHz +9dbm
20MHz-50dbm
30 MHz -37dbm
no obvious higher harmonics
broad noise
