[ntp:questions] Re: Comparing offset of multiple refclock/servers
Ulrich.Windl at RZ.Uni-Regensburg.DE
Mon Aug 22 08:51:26 UTC 2005
hmurray at suespammers.org (Hal Murray) writes:
> Back to UPSs. It might be interesting to try a measurement near
> the ones that don't cause problems. My guess is that they are
> trashing some other frequency. 60 KHz is pretty old for switching
> power supplies. Small ones are in the MHz now.
One reasons why DCF77 does no longer work here is the setup of a MGE Comet S31
(10kVA UPS). As I learned, that UPS uses pulse width modulation, effectively
causing to overlay the DCF77 signal by some magnitudes. Talking to MGE tech
persons I learned that they "don't know of any problems", and "they will not
change their design". Effectively this means that no DCF77 will work within 50
meters of such an UPS.
More information about the questions