I have considerable experience operating Thunderbolts in less than optimum
conditions (my house is in an urban jungle, surrounded by Jurassic trees and
nasty multipath monsters).
Lady Heather defaults to the dBc setting since that seems to be the most
understandable and better defined system. Signal levels above 40 are very
good. There seems to be little to be gained with signals above 40. Above 35
are OK-ish. From 32-35 are usable, if you are not too picky about your
system. Below 32 are just plain craptastic and pretty much unusable.
The most problematic and intractable source of Tbolt output errors seem to be
the result of satellite constellation changes as the unit constantly switches
between satellites in an effort to track the "best" available satellites.
If you plot the satellite count and DAC voltage (and along with the PPS error
estimate) you will see that the DAC voltage changes with every satellite
constellation change. This causes the oscillator to change frequency.
The better your signal levels, the less reason the unit has to switch tracked
satellites and the better will be your oscillator and PPS outputs. The Tbolt
firmware supplies few tools for minimizing its annoying habit of tracking the
supposedly "best" satellites of any given instant.
At my location, I am doing real good if the tracked satellite constellation
stays fixed for over a minute...
_________________________________________________________________
Windows 7: I wanted simpler, now it's simpler. I'm a rock star.
http://www.microsoft.com/Windows/windows-7/default.aspx?h=myidea?ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_myidea:112009
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