[ntp:questions] Configuring FreeBSD 6.2 for use with Garmin GPS 18 LVC

Dennis Hilberg, Jr. timekeeper at dennishilberg.com.invalid
Thu Dec 20 17:42:06 UTC 2007


David J Taylor wrote:
> Dennis Hilberg, Jr. wrote:
> []
>> I knew you weren't joking.  However, I need to solve my sudden
>> lack-of-signal issue before I do anything.  GPS satellites don't
>> change orbits suddenly do they?  Or at all?
> []
>> Dennis
> 
> Dennis,
> 
> Satellites do fail, and are replaced.  Batteries wear out, thruster fuel 
> comes exhausted and so forth.
> 
> They do not change orbit suddenly, however....
> 
> The Chinese recently did shoot down a satellite of their own in a much 
> lower orbit, creating lots of debris which could affect other 
> low-earth-orbit satellites.  GPS satellites orbit higher than this, and 
> are unlikely to be affected.
> 
> You could use a terminal emulation program (in Windows, FreeBSD or 
> whatever) to see what is coming down the line from the GPS18 LVC.  I also 
> have a Windows program which will plot the signal strength received from 
> each of the 12 channels.
> 
> One possibility may be that the GBS18 has switched to "Garmin" mode 
> instead of NMEA mode.
> 
> Cheers,
> David 

Well I am getting signal, but it's intermittent.  I know it's in NMEA mode 
as I've tailed the clockstats file, and have run gpsd and used the 'cgps' 
test client.

I have yet to move the GPS 18 LVC around to see if I can get a better signal 
from somewhere else.  It's just odd that it would work fine for a number of 
months as is and then all of a sudden stop receiving a steady signal.

I will try your WXtrack program too.

-- 
Dennis Hilberg, Jr.      timekeeper(at)dennishilberg(dot)com
NTP Server Information:  http://saturn.dennishilberg.com/ntp.php




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