[time-nuts] thunderbolts not seeing satellites

James R. Gorr n3toy at yahoo.com
Sun Jan 3 20:13:32 UTC 2010


Hello everyone! Hope your new year is going well so far.

I have two Tbolts (one from TAPR and one from another guy), and neither one is locking on satellites.

My set up is a Lucent antenna, about 12 feet of LMR400, a Symmetricom 4 way Active "SmartSplitter",  then about 3 feet of LMR 195 to my non-TAPR Tbolt.  I have another GPS (non Tbolt) on the SmartSplitter also (that works fine, ie: is RX satellites).  This set up has worked for a couple years.  

I originally powered my non-TAPR Tbolt with three "wall warts".  When I got this GPS, I was told it took non-standard power of +12/+5/-7.

A while ago I noticed my Tbolt stopped working.  I took it offline and replaced it with one I bought from TAPR a year previous.  Additionally, I powered my "new" Tbolt with an HP 6236B, and everything worked fine.

Now, this morning I noticed my Tbolt is not working again!

It powers up, draws expected current on start up (then backs down after oven warms up) and I can monitor it with tboltmon.exe.  

I did a factory reset then manually input my position.

No critical alarms are showing (all green) and minor alarms are all green except for: Satellite Tracking, Oscillator Disciplining, and Almanac, which are yellow.

I have all 0.0 AMUs under Signal Levels.

I think because the other GPS (non-Tbolt) works, my antenna and splitter is fine.  

I have also tried switching ports on the splitter.

I have tested my jumper cable for shorts and continuity. 

Interestingly enough, if I power my original Tbolt (the +12/+5/-7 one) from the wall warts, it will "see" 2 satellites, but with very poor signal strength.  It will not see anything powered with +12/+5/-12 from the HP PS.

Both Tbolts have the same symptoms.

Anyone ever see issues like this?  Or have any suggestions?

Jamie





      



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