Alan, Thank you for such a clear explanation! I understood the process, and why, but having someone actually put numbers to it helps in getting that "gut feeling" as to why... Thank you!! -- 73's, and thanks, Dave (NK7Z)
For software/hardware reviews see: http://www.nk7z.net For MixW support see: https://groups.yahoo.com/neo/groups/mixw/info For SSTV help see: http://groups.yahoo.com/neo/groups/MM-SSTV/info On Mon, 2016-03-07 at 09:56 -0800, Alan wrote: > The indicated noise level depends on the receive bandwidth. For > example, if you use a narrower bandwidth on the K3, you'll notice > that > the S meter reads lower. > > 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. If the K3 bandwidth is 2.7 > kHz, > then the P3 should read 10 * log (2700/100) = 14 dB lower than the > K3. > 14 dB is roughly 3 S-units. > > When measuring a steady carrier, the K3 and P3 should read the same, > since all of the signal is within the bandwidth. The P3's amplitude > can > be calibrated with the "Lvl Cal" menu selection. > > Alan N1AL > > > On 03/07/2016 03:14 AM, Brian J. Linn wrote: > > All: > > > > > > > > Even after considering the P3 manual (page 21) and with AGC off, I > > find the > > following difference in S unit measurement odd. > > > > > > > > > > > > Band P3 K3 > > > > 75m S5 S9 > > > > 10m S0 S2 > > > > > > > > > > > > I'm trying to ascertain an accurate noise level reading at my > > QTH. Does > > anyone have any thoughts on the degree of difference in these > > readings? > > > > > > > > Brian KD0HII > > > > > > > > > > > > ______________________________________________________________ > > 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 > > Message delivered to [email protected] > > > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
