Actually, you don't need to calibrate the P3 at different levels. The ADC is linear within a tiny fraction of a dB over its whole range, so once you calibrate at one level, all levels should be accurate.
But you bring up a good point about needing a different signal source for each band. I guess I should include a "global" calibration that applies to any bands that haven't been calibrated. Alan N1AL On Mon, 2010-08-30 at 13:36 -0700, Mike Scott wrote: > Given Alan's plans, I detect a need for an XG3 now that he wants to make the > P3 amplitude calibration per band. > > > > The XG3 could be ten band 160 through 6M accurate 50 uV and 1uV source. > Actually I might want something other than 1 uV as that is an awkward value > between S3 and S2. > > > > So a 10-band source with -73 dBm and -103 dBm outputs might be better > because -103 dBm would be S-4 for those who like 6dB per S-unit and S-3 for > those who want 5dB per S-unit. > > > > AE6WA > > Mike Scott > > Tarzana, CA > > > > ---------------------------------------------------------------------------- > ------------------- > > Alan N1AL said: > > On my list of features to add is amplitude calibration, similar to the > > S-meter calibration in the K3. I plan to make it per-band to account > > for variations in the K3 RF chain and to separately measure the gain of > > the K3's preamp and the attenuator. This level of accuracy isn't really > > needed for normal operation of a radio, but as an ex-Agilent/HP engineer > > I'm kind of a perfectionist when it comes to measurement accuracy. :=) > > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
