[time-nuts] Trimble Resolution-T SMT caught behaving badly

Mark Sims holrum at hotmail.com
Tue May 15 01:11:57 UTC 2012


Attached is a Lady Heather screen dump of a Trimble Resolution-SMT timing receiver behaving badly.  The first quarter of the plot the unit was tracking all sats above 0 degrees/0 dBc.  The next quarter the masks were set to 30 degrees/30 dBc.   Then at the half way point,  something strange happened...

The green plot is the sawtooth correction value.  It should be +/- 15 nS,  but was only running +10/-13 ns.  At the half way point the sawtooth started spiking down to -38.000000 ns...  obviously some internal clipping limit.   It ran this way for a day,  then I reset the unit and all has been well since.

The purple plot is the unit's "local clock bias".  It is reported like the Tbolt's PPS value.    It is a sawtooth that covers a 1000 usec (almost) range. It repeats over a 28 minute period.

The white plot is the "clock bias rate".  In comes in like the Tbolt OSC value.  Yellow is temperature.   Note how well those two plots track each other.   Suggests that some active temperature control might be useful.

One nice thing about the Resolution receiver is that it returns tracking info for all sats,  even those below the elevation/signal masks.  This lets you build a signal level map even when you have elevation and signal level masks set.   Also note the high signal levels.  On a Tbolt,  I never see signals past green... the receiver is 6 db more sensitive.



 		 	   		  
-------------- next part --------------
A non-text attachment was scrubbed...
Name: rest.gif
Type: image/gif
Size: 73572 bytes
Desc: not available
URL: <http://febo.com/pipermail/time-nuts_lists.febo.com/attachments/20120515/c4108e25/attachment.gif>


More information about the Time-nuts_lists.febo.com mailing list