[time-nuts] Trimble Nortel GPSTM Boards

GandalfG8 at aol.com GandalfG8 at aol.com
Mon Aug 5 20:06:27 EDT 2013

Many thanks to those who commented on this and apologies for the delayed  
response, having spent a few days in an internet free zone I've also had to  
contend with a couple of power failures since returning but am just  about 
getting back to normal again, whatever normal might be:-)
As suggested, changing the elevation mask does make a difference to the DAC 
 voltage jumps, I'd just run up Lady Heather on default settings to start 
with  which sets it to 10 degrees and changing that to 20 degrees, for  
example, has reduced the steps in the DAC voltage as sats come and go,  they're 
still there but not so pronounced.
Having said that, comparing this with a Thunderbolt, albeit using another  
Thunderbolt as the reference for both, does tend to give more  pronounced 
steps on the Thunderbolt for the same elevation mask and sensitivity  settings.
As others have commented previously I'm also noticing the much reduced  
temperature sensitivity of this unit compared with the Thunderbolt which is  
quite a big plus, but it's not all totally one sided, both Lady Heather and  a 
couple of Pendulum counters are showing somewhat lower Adev values for  the 
Thunderbolt although the plots of frequency against time show very  similar 
Either way, so far at least this does seem to be working well. I still  
haven't heard from anyone who's run the two available GPSTM variants side  by 
side so I'm still debating whether or not to try that for myself,  or whether 
to just quit whilst I'm ahead:-)
In a message dated 31/07/2013 22:48:13 GMT Daylight Time, GandalfG8 at aol.com 

Having  stuck a late bid on a recent auction for what I'd  assumed was a  
Trimble Nortel NTGS50AA I then realised I'd  just bought the single  board 
version, part number 4500-00-CH  with the Trimble 49422-CR  OCXO.

That in itself wasn't a problem, except perhaps the doubts cast  over  my 
sanity:-), it arrived earlier today and has been   running for several 
now, chatting comfortably with  Lady  Heather, and generally settling in 

However, it does prompt the  question, has anyone had a chance to compare  
one of these side by  side with an NTGS50AA and, if so, were there any  
obvious differences  in  performance?



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