[ntp:questions] ntpd: time reset problem

Unruh unruh-spam at physics.ubc.ca
Fri Sep 18 02:51:55 UTC 2009

David Lord <snews at lordynet.org> writes:

>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.

I have my GPS18 buck on the banister of my front porch. House behind it,
taking up half the sky. large maple trees on the street about 10 or 15m
in front of the house along the street- each at least 20-25m high
 cutting off another 50% of the still available
sky. But it still works and gives me the time. 

Ie, a rooftop is almost certainly much better.

>> 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.


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