[time-nuts] Spread Spectrum Spam!

[Lux, Jim (337C)]

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" <robert8rpi at yahoo.co.uk> 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.
>