Given the extreme output range (450Hz to 800MHz) it must have a DDS with no filtering at each output, right?
I don't think the mystery TCXO runs at 1.6GHz, but some GPS-TCXO inside is instead multiplied way way up. Tim N3QE On Mon, Oct 19, 2015 at 8:20 AM, Attila Kinali <[email protected]> wrote: > On Sun, 18 Oct 2015 17:56:36 -0700 > "Burt I. Weiner" <[email protected]> wrote: > > > I just ran across this and wonder what you think. > > > > > http://www.force12inc.com/products/gps-locked-precision-frequency-reference-low-jitter-gps-clock-450-hz-to-800-mhz-output.html > > > > Seems like it could be set up as a reference to replace crystals in > > some Ham rigs such as a repeater transmitter and receiver. > > > I've seen this being mentioned a couple of times in the past weeks. > The phase noise looks ok'ish. Not great, but not too bad either. > Though I doubt that he'll be much below the noise floor of his instrument. > 140dBc is about what you get with most VCXO/TCXOs. To be better you > need to know what you are doing and/or use a good oscillator, which > becomes expensive (a good, low noise VCXO costs already 100USD > in small volumes unless you build it with discrete components, > which then takes considerable knowledge). > > An ADEV plot and any kind of schematics are missing completely. > Also without any reference, I would distrust the way how the > system is build. There are ways how people trying to do the right > thing will mess up in subtle ways. (e.g. like using an FLL instead > of a true PLL, as is the case for the BG7TBL GPSDO) > > For 200EUR, it's also on the expensive side, if you compare it with > what you can get on ebay. Of course, there is the difference between > a used device and a new device. > > On a personal note, the product description reads too much like > "hey, the guy who designed this is really really great!" > I am not sure what I should make of that, but I don't think that's > a positive attribute. > > In summary, I'd probably wait for a time-nuts to get his hands on this > litte gadget and do some serious measurements before I'd trust it. > > Attila Kinali > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
