Yes, this last is exactly my same experience with the DCF77: the receiver used alone with a linear power supply was running fine, connected to the PC or a microproccesor board with a switching power supply was a problem.
On Wed, Jun 27, 2012 at 5:59 PM, Kasper Pedersen <time-n...@kasperkp.dk>wrote: > On 06/27/2012 04:04 PM, Tony Finch wrote: > > > Are there any basic steps I should take to improve the reception quality > > of a radio clock? I have a cheap and cheerful DCF77 receiver for > > connecting to some GPIO pins, but its PPS output is basically noise with > > maybe a one-second period. Perhaps it's just cheap and nasty. > > > > > Be careful what you connect the ground of the receiver to. > > When I did my DCF77 receiver, my first source of interference was the > common noise on the output of the supply I was powering it off of. > I went to a linear power supply, and things were good for a few years. > > Then they installed remote-reading power meters in the neighbourhood, > and DCF77 was completely jammed. The meters talk back on 75kHz with > ~6kHz bandwidth. Halfway by accident I found out that if I earth the > receiver well enough, thereby shunting off some of the 75kHz common mode > signal, I get mostly reliable reception all day. > > I would suggest, at least for development, a battery and an optocoupler > to isolate the receiver section from conducted interference. > > Hmm, I do have a Pi. > And when you have trouble decoding the signal at around 04 in the > morning, you too will have rediscovered sferics, and the need for a > filter that handles that. > > /Kasper Pedersen > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
