-------- In message <[email protected]>, Bob Camp writes:
>> See also http://leapsecond.com/pages/fe405/ and the links near the bottom. >> This (patented) FEI design avoids the spur issues several of you have been >> talking about: the RF output comes from a low-noise VCXO not the low-drift >> OCXO+DDS itself. >> > >It avoids the far removed spurs. If you have a close in spur, it passes right >through the PLL loop and messes up your ADEV. >Yes, this really does happen on real gear in the real world ….. Going (almost) 5MHz -> 15 MHz -> 15MHz is just asking for low frequency trouble. If I were to design such a product, I would pick the stable OCXO to have a frequency well removed from the target frequency on as many decimal digits as possible. 3.1415926535... MHz if I could get away with it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ 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.
