[time-nuts] Thunderbolt test results

Bob Camp lists at rtty.us
Wed Jun 16 16:18:49 UTC 2010


The Andrew boxes most of the TBolts came out of were designed for E-911
location service. The idea was to use time difference of arrival at multiple
sites to triangulate a cell phone. For what ever reason, they decided a
"fast tracking" of GPS time was going to give them the best results. I think
that was the wrong decision, but that's what they went with.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of John Green
Sent: Wednesday, June 16, 2010 9:32 AM
To: time-nuts at febo.com
Subject: Re: [time-nuts] Thunderbolt test results

The default parameters are a compromise. The thunderbolt was originally used
to provide time and frequency, though I understand not always frequency, for
cellsites. Though heated and air conditioned, I suspect they had pretty good
temperature swings. Also, the sky view was not always optimum. It was
supposed to lock on to as few as 1 SV, come up from dead cold and work.
Obviously, those settings can be improved upon when we stabilize the
temperature, voltages, use good antennas. I use one as a reference for an
amateur repeater and it works well for that. When I was trying to put the
repeater on the air, I changed the settings from default to what I had found
in the lab that worked better and the Tbolt went into holdover and wouldn't
come out. I changed back to the default settings and it worked fine. I am
not sure why they didn't work but I didn't have a lot of time to
investigate. Months later, it is still working great. There are people here
that have spent many hours optimizing the Tbolt. Search back and you will
find lots about how to get the most out of it.
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