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Re: Spectrum Analyser - screen dumps
Posted: Tue Jun 19, 2018 10:29 pm
by K9AQ
John
It appears that the noise floor of the RAS SAS isn't flat, it almost appears to be modulated by a lower frequency signal. The raising of the noise floor might explain the couple of db difference. I would like to know if there is a way to flatten out the noise floor. This is a small "nit" for me. The SDR Play is way cheaper than the HP SA!
Don
K9AQ
Re: Spectrum Analyser - screen dumps
Posted: Wed Jun 20, 2018 10:01 am
by JohnAE5X
Right, I was looking at that too. This Saturday I want to measure again with a higher output from the KX2 (a full watt). It shouldn't make any difference in harmonic relationship but it may in relation to the noise floor.
Re: Spectrum Analyser - screen dumps
Posted: Wed Jun 20, 2018 11:33 am
by SteveAndrew
K9AQ wrote:It appears that the noise floor of the RAS SAS isn't flat, it almost appears to be modulated by a lower frequency signal.
JohnAE5X wrote:Right, I was looking at that too.
I'm not entirely sure I understand what you mean when you say the say the noise floor seems to be modulated by a lower frequency. The noise can be reduced by selecting Average on the display panel. I've notice some artifacts at the lower end of the spectrum, but they seem to vary, depending which RSP device I'm using. If possible, could you show a couple of screen shots highlighting the modulation effect ?
John - I had a quick look at your blog, and I'm pleased to see the analyser gives a good account of itself when stacked up against an HP analyser. I look forward to seeing how it goes with further testing.