On Tue,7/28/2015 7:38 AM, Alan Bloom wrote:
On 07/27/2015 10:46 PM, Jim Brown wrote:
On Mon,7/27/2015 10:28 PM, Phil Wheeler wrote:
Oh oh, Jim: We need a P3A :-) Good you took this on.
Perhaps P3 firmware can be re-written to allow display of greater
dynamic range to the extent that electronics headroom supports it?
The limit is the 32-bit arithmetic in the DSP firmware. 32 bits gives
you 96 dB less some headroom to allow for the averaging function. I
tried floating-point arithmetic but it increased the computation time
by more than an order of magnitude.
Understood, and clearly the right design compromise. My data is the
accumulation of peaks, without averaging. Might it be possible for a
special "measurement version of the firmware that would squeeze another
10 dB?
As you said, you can see the improved phase noise performance of the
new synthesizer by simply cranking up the reference level and allowing
the carrier to go off the top of the screen. Perhaps someone will do
that when upgrading to the new synthesizer and post before and after
plots. (Didn't somebody already do that?)
I did see some work like that posted done with an analyzer with less
frequency resolution, and the results clearly showed the improvement.
Thanks and 73, Jim
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