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On Mon, Jan 20, 2020 at 07:06 PM, jafinch78 . wrote:

1. Have you made changes that reduced the dynamic range using the Si4432 vs the Si5351?? Seems where I left off following in detail last winter... you had a lower noise floor reported.? I may be wrong and need to read through again.? If this is a correct observation, was this due to settings like decimation or something in the design??

I never did test a SI5351 as oscillator for the SI4432. Phase noise and noise floor are good enough for my applications (testing harmonics and other spectral content in home build transceiver) The decimation remark was related to spectral purity measurements using an RSP1. More decimation in the RSP1 reduces the noise floor of the RSP1

2. Reading regarding phase noise, is the 30kHz bandwidth the only issue and what limits this?? Would something like a Cross Correlation significantly improve performance (double up the spectrum analyzer modules like TSP#162 notes about 34min in and better @ 36min in)??

I am aware about the cross correlation method, it requires double hardware and long measurement time but because the RSP1 is already able to observe the phase noise I can use it to see in real time if anything I do to the tinySA improves the phase noise.
But the tinySA is best at observing its own phase noise by using the 10MHz calibration output. Anything you do to clean the power supply and shield noise is directly visible
Here is a picture. The purple line is when I started and after tightening the SMA connectors I got the blue line



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HBTE Files section:?/g/HBTE/files
Erik, PD0EK