[ntp:questions] ntpd: time reset problem

David Lord snews at lordynet.org
Fri Sep 18 00:12:44 UTC 2009


David J Taylor wrote:

> You'll have to get a GPS puck and wireless PC on the roof!  Safely 

That looked a possibility earlier this year but treeline front
and back has shot up maybe a couple of metres already and if
same next year I'd be needing a mast.

> hidden in some cupboard up there.  Or even power-line connections 

I'm signed up in protest at various network over mains systems
due to them splattering and killing QRP reception.

I hope the problems with MSF yesterday were a one-off, there
was a lot of noise from what I took to be machinery nearby
during that period but I couldn't see from out of window and
when I went out to check there was nothing and of course when
I got back MSF was received ok. Previously over 4 days with
Conrad module tuned to MSF and logging ntpd, the reach had
stayed at 377 throughout.

> I built a loop using multi-strand cable inside a 1m diameter copper 
> central-heating pipe (the pipe being open circuit, of course!), but at 
> that time with CRT displays and TVs there was just too much 
> interference. Having said that, the simple radio clocks which Maplin 

Not sure about the Conrad module but my diy receiver uses a
balanced input amp and output gives a reasonably stable trace
on scope but if either input is grounded the output is just
noise although slight 1Hz pulse can still be seen.

I've not mastered the demodulation though and whilst on scope
it looks to be a clean and identifiable MSF timecode no
different than from Conrad module, a much closer look shows
noise spikes. I used an RC filter at output and suspect a
Schmitt as with Maplin circuit is needed.


David




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