So it does! And to think of all my unnecessary REF LVL adjusting. One of these days I'm going to have to spend more time with that thing called a manual.
Thanks and 73, Mike ab3ap, who -thought- he read it through. On Jan 3, 2012, at 11:39 PM, Alan Bloom wrote: > The P3 already does this if you have MENU:SpanScale set to anything > other than "OFF". > > Alan N1AL > > > On Tue, 2012-01-03 at 19:52 -0500, Mike Markowski wrote: >> I'll follow up on my own note because there's nothing as helpful as an >> example: >> >> 1) I move to 17m band with P3 set for +/-100 kHz span >> 2) P3 REF LVL knob used to set -122 dBm to match noise level at my QTH >> >> 3) -122 dBm = 6.30957 x 10^-13 mW >> 4) Since noise power N = kTB, (k is Boltzman's constant), >> T = N / (kB) = 6.30957 x 10^-13 / (k x 200 kHz) >> k = 228500 K <--- recalc when REF LVL knob is twiddled again! >> >> Now I want to change P3 span to +/-5 kHz, or B = 10 kHz: >> >> 5) N = kTB = (1.380648813 x 10^-23) x 228500 x 10x10^3 >> = 3.15479 x 10^-14 mW >> = -135 dBm <--- new REF LVL setting, send to P3 >> >> Easy to add to firmware? If not, it is easy to add to external >> software. The only thing not automatic is that the initial manual REF >> LVL setting is required to take into account antenna system noise >> presented to the P3. >> >> I hope other REF LVL twiddlers find this useful. 73, >> >> Mike ab3ap ______________________________________________________________ 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
