> My first question is: what is a reasonable setting? It's kind of a "season to taste" -- whatever gives a pleasing display to your eyes. When the waterfall is turned on, I find that it's best to adjust the REF LVL so that the noise level is right at the bottom of the spectrum screen. That seems to make weak signals easiest to spot on the waterfall.
> I am not quite sure how accurate this is. I would guess that typically it should be within a few dB. Let's say within one S-unit (6 dB). I plan to add a feature so you can calibrate it against an accurate signal source. > ...and noticed that this particular SSB signal on 17 meter band this morning > read peak about -100 dBm or about a 32 dBm strength over the minimum reading > on the scale. I would like to equate this to a rough idea of an S meter > reading. By my calculations, this should be a little bit above an S4 > reading. Can someone confirm that I am in the right ball park? What I do is to remember that S9 is -73 dBm (an easy number for a ham to remember) and there's 6 dB per S-unit. So -100 dBm is (100-73)/6 = 4.5 S-units below S9. So between S4 and S5. Another item on my "to-do" list is a MENU option to change the scale from dBm to S-units and dB over S9. It's not all that hard to do, I just need to clear some higher-priority tasks off the list first. Alan N1AL On Sat, 2010-09-04 at 09:12 -0700, Phil Hystad wrote: > I am trying to get a better understanding of the P3 signal level scale (left > vertical scale) with respect to absolute signal levels and the S meter > readings. > > I have my REF LVL set to -132 dBm. My first question is: what is a > reasonable setting? I merely am guessing at the value of -132 dBm and also I > am not quite sure how accurate this is. According to the P3 manual, this is > essentially the signal strength at the antenna terminal of my K3 (taking into > account the pre amplifier which I happen to have Off). > > Also, I was monitoring a signal using the PEAK reading capability of the P3 > and noticed that this particular SSB signal on 17 meter band this morning > read peak about -100 dBm or about a 32 dBm strength over the minimum reading > on the scale. I would like to equate this to a rough idea of an S meter > reading. By my calculations, this should be a little bit above an S4 > reading. Can someone confirm that I am in the right ball park? > > Thanks for the help. > 73, phil, K7PEH > > ______________________________________________________________ > 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 ______________________________________________________________ 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
