According to Al, N1AL, "The effective bandwidth of the P3 is approximately one pixel on the display, which is SPAN/468. So, for example, if the span is 47 kHz, the effective bandwidth is about 100 Hz."
To "convert" or "correct" to a 1 Hz bandwidth, use the formula: BW_correction_factor = 10 * log(P3_effective_BW) For instance, to "convert" a 100 Hz effective P3 bandwidth to 1 Hz, the factor would be 20 dB. So, if you measured a noise level of -80 dBm on the P3 whose effective bandwidth were 100 Hz, that would really be -100 dBm in a 1 Hz bandwidth. Al W6LX/4 On Tuesday, June 7, 2022, 11:06:05 AM EDT, Dave (NK7Z) <d...@nk7z.net> wrote: Hi, I am contemplating practicing some phase noise measurements using a P3. If I correctly understand the measurement, (which I may not), I should express the result, using db down from peak, so many Hz away from peak, using a 1 Hz width. First question; is the above correct? Second question; (amusing Q1 is correct), what is the pixel width of the P3, and can I just divide that width by total frequency spread shown on the P3, and assume that number I get is correct for width per pixel in Hz? Third question, (assuming Q2 is correct), once I get a number from question 2, can I then just divide that result by X, where X is selected to bring the width of measurement to 1 Hz? Thanks in advance for any help in this... -- 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
