Some synth sig-gens use the reference divided down to drive the PSU (Marconi 2955 for instance) for the same reason I think Alan G3NYK
----- Original Message ----- From: "Lux, Jim (337C)" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Friday, November 27, 2009 10:03 PM Subject: Re: [time-nuts] Spread Spectrum Spam! Some spacecraft have a requirement that all the PWM supplies by synchronizable to an external source. The idea is that at least the spur is in a constant location, rather than wandering around (PWM natural switching rates not being the most stable in the world) On 11/27/09 12:40 PM, "Robert Atkinson" <[email protected]> wrote: > Interestingly some amateur radio 13.8V switch mode supplies have a QRM > (interference) reduction control. This shifts the PWM frequency slightly so > you an shift the noise off of the signal you are listening too! Complete > fudge. In Europe the CE EMC tests use Quasi-peak detectors and slow scan rates > that respond less to spred clocks. The spreading can be turned off in the BIOS > on most machines if needed. > _______________________________________________ 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.
