I should not type when tired. That should have read "this is good", not goof.... sorry about that..
73 K1NR On Mon, 14 Jun 2010 22:04:31 -0400 "Eugene Balinski" <euge...@nni.com> wrote: > 10 MHz is an industry standard. This is goof. However, > you might want to consider a 1PPS GPS-trained input as > well. > > 73, > Gene K1NR > > On Mon, 14 Jun 2010 16:15:39 -0700 > Wayne Burdick <n...@elecraft.com> wrote: > > There appears to be more demand for this than we > thought, > > so we're > > looking into it again. > > > > Note that our planned external reference implementation > > would not > > require an exact 49.380000-MHz reference oscillator > > signal. It also > > doesn't require a pin-1 control voltage input on the > TCXO > > module > > itself, as suggested earlier. It should work with any > > existing K3 > > TCXO, either +/- 5 or +/- 1 PPM. > > > > If you're interested, here are the details: > > > > A new REF-lock module would be designed that plugs into > > the small 8- > > pin connector near the top of the KREF3 PCB. The user's > > 10-MHz > > reference signal would be routed from the rear panel to > > the TMP > > connector on the KRE3 (this connector faces forward, > into > > the DSP/ > > front panel area). > > > > A microcontroller on the REF-lock module would be > clocked > > by the 10- > > MHz reference. If the signal were present, the > > microcontroller would > > continuously measure (and average) the frequency of the > > 49.38 MHz > > oscillator, obtaining a value to the nearest 1 Hz. > > Hysteresis would be > > applied to prevent "hunting," so the actual accuracy > spec > > would > > probably be +/- 2 Hz. This translates to about +/- 1 Hz > > in operating > > frequency on 20 m. > > > > Approximately once per second, the module would report > > the actual > > reference frequency to the K3's main MCU via a slow > > digital data line > > (labeled "100HZ" on the RF and KREF3 schematics). The > > main MCU would > > use this to calibrate the REF CAL value normally > entered > > by the user. > > There would be no noticeable impact on performance. > > > > If the 10 MHz external signal were not present, the > > user's normal REF > > CAL value would be used. > > > > Let me know if you have thoughts on this > implementation. > > > > 73, > > Wayne > > N6KR > > > > > ______________________________________________________________ > > 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 > > --------------------------------------------------------------------- > Web mail provided by NuNet, Inc. The Premier National > provider. > http://www.nni.com/ > ______________________________________________________________ > 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 --------------------------------------------------------------------- Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ ______________________________________________________________ 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
