I should like some advice, please, as to where I am going insofar as my calculation of the 1Hz noise power is at this rural I studied all of this over 30 years ago, so I'm more than a bit rusty!
I have the XG-2 which I can only assume is working as it should, delivering -73dBm. On the P3 this shows as -79dBm. Can I therefore assume that all other measurements will have this same systematic error? I'm comparing noise floor figures with a friend who is in a city location. He has a Perseus SDR and is measuring the noise floor in a 270Hz span, so to compare my figures (in a span of 2kHz) with his, I'm converting both sets to the standard noise power in a 1Hz bandwidth by applying a correction of 10log(span in Hz). This looks right for his data and correlates well with the sort of results he is seeing on WSPR, but for me I'm getting ridiculously low noise floor figures approaching the -174dBm noise floor associated with a temperature of 300K. On 30m at the moment, in a 2kHz span I have an averaged noise floor of around -130dBm (not taking into account the -73dBm XG-2 looking like -79dBm). 10Log 2000 = 33dB, so that makes my 30m noise floor in a 1Hz bandwidth -163dB which clearly it cannot be. I'm doing something wrong somewhere. BTW, I do appreciate that I haven't paid for a lab grade instrument! I've only my brain to blame! 73 Stephen G4SJP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
