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/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html
Locked
