>>> Upon further reading, the corrections of this module appear to be in ~1Hz >>>steps. >>> I was more interested in something that disciplines the oscillator in a >>>finer more continuous way.
I have a K3EXREF on order from Aptos, as well as a Trimble Thunderbolt coming via E-Bay. The Trimble Thunderbolt produces two outputs, a 10.000000 MHz sine wave and a 1 pps pulse. The 10MHz sine wave will be sent to the EXREF, which will then use that to phase-lock an oscillator internal to the K3. I'll leave it to you to study the EXREF installation/user's manual as well as the K3 schematics (which are downloadable from the Elecraft web site) to see precisely how that's done. But from what I've read so far, if you want sub-Hertz accuracy for the FMTs, etc., you'll need to zero-beat to WWV, count your nulls, and then calculate and apply a correction factor to your measurements. Otherwise, you're going to be looking at some very long integration times to ensure that your local oscillator is at 10.0000000 MHz (or whatever). There may be some newer devices out there that output a higher frequency reference signal, and if so, I suspect that they would be very, very expensive. My informal research indicates that the Thunderbolt listed at around $1200-$1500 new 10+ years ago, and obviously used ones on E-Bay are much less expensive, but if you were looking for something better than that (a rubidium or cesium oscillator?), the cost will be considerably higher. K5CM has published a couple of interesting papers at his website, http://k5cm.com, and KE5FX's Lady Heather's disciplined oscillator control program web page helps explain some of the short- and long-term frequency tolerance issues at http://www.thegleam.com/ke5fx/heather/readme.htm which would be well worth your while to study. Another good source of information for you might be the Time Nuts: http://www.leapsecond.com/time-nuts.htm Hope that helps! 73, Brandy, N1HO ________________________________ ______________________________________________________________ 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
