Re: Microwave Noise
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And to add to that, multicarrier systems like OFDM obey all (I think; certainly 'very nearly all') the tests for a Gaussian noise waveform. Even a comb of a large number pure sinusoids does.
The question really came about after reading an article in the latest QEX about noise monitoring and WSPR, where they use two methods of measuring noise, both of which I've adopted in the past. The RMS of the time domain signal, measured during the quiet period of no WSPR transmissions. And the FFT techniques where the bins are put into order of power and noise deemed to be the level in the bin at the 30% point ( I use the lower quartile plus 5dB - thoughts on this differ but the delta is minimal)
In that article they mention that often the two measurement methods give significantly different results, and at other times are very close. This is put-down to the non-Gaussian nature of noise at HF. Hence my thoughts at higher frequencies.
On Wed, 16 Sep 2020 at 12:20, Chris Bartram G4DGU <chris@...> wrote: