[time-nuts] Nortel/Thunderbolt questions

[Bob Camp]

Hi

I believe what you have here is a Trimble / Nortel box rather than a TBolt - is this correct?

If so there are a number of differences in what you can and can't do with LH. Also since it's a different design, the filter is set up differently. 

That said, it should show lock, sats, dac voltage, and status correctly. 

Bob

On Jul 12, 2013, at 3:56 PM, Jim Sanford <wb4gcs at wb4gcs.org> wrote:

> All:
> My Nortel receiver has been running for 6 days now.  I am running the Lady Heather software, but also have TBOLTMON.  It shows my position fairly well, but I have seen a negative altitude, and am currently seeing 1565' altitude.  Based on local maps and the GPS in the car, I believe the antenna to be no higher than 1280'.  I get lock with 4 to 6 satellites colored green.  I have seen PHASE LOCKED, but am currently seeing "recovery mode" and the LOCKED LED on the unit is flashing, which I think I remember means recovery.
> 
> I have several questions:
> 1.  Sometimes position is displayed in yellow, sometimes in white. What is the significance of the color?
> 2.  I see TC 100.0 sec, DAMP1.200, GAIN 1.2 Hz/v, INIT 3.00V. When I go to KE5FX site, his values for TC, DAMP, Gain and INIT are very different.  In particular, if DAMP is damping in a control loop, I am not surprised that my very overdamped unit is not locking.   Question:  Are these parameters that will converge, or are they parameters I should try to set?  The heather.cpp files suggests that they may be settable, but does not say how.
> 3.  On my plot, I see an RMS value in green, which suggests to me that something is happy with the DAC voltage, even if very different from John's.  The scale is 100000uV/div which suggests to me that it is NOT locked.
> 4.  On my plot, I see an RMS value in yellow, which suggests to me that the temp is OK, but the scale on temp is growing.... at the momoent, 10mC/div; John's is 50 mC/div, but a much smoother plot than mine.  What is this telling me?
> 
> ROM,RAM, OSC, FPGA, POWER, EEPROM, ANTENNA, ALMANAC, DISCIPLINE, SAVED POSITION status are all OK, even though altitude is bad.
> Can anyone help me understand what I am seeing, and in particular, why it won't lock, or stay locked, when it is seeing good sat signals?
> 
> Thanks!
> Jim
> wb4gcs at amsat.org
> 
> 
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