[time-nuts] A few questions about Tboltmon

Bob Camp kb8tq at n1k.org
Thu Aug 6 06:39:00 EDT 2015


> On Aug 5, 2015, at 10:16 PM, Chris Waldrup <kd4pbj at gmail.com> wrote:
> Hi,
> I got my new Thunderbolt up and running this past weekend but I have a few questions. I understand Lady Heather is a better program, and I have downloaded it. However right now I am trying to get things right with Tboltmon first. I had used it with my previous GPSDO, a Starloc II. I hate to say but the Starlic just worked, so I didn't pay much attention to Tboltmon other than to see that I was seeing satellites. Please forgive me if some of the questions may sound simplistic, but I'm sort of new to being a time nut. 
> The Thunderbolt is brand new in package. I purchased a Power One open frame supply from EBay that was also new old stock. Before connecting it to the Thunderbolt, I went ahead and ordered new electrolytic caps from Mouser and spent last Friday night recapping the Power One box. I measured the outputs with a DMM to make sure I had 5 V, -12 V and 12 V. 
> Noticing that in my old antenna location I could now only see 1-2 satellites (trees have grown a bit) I moved the antenna to the roof of my house, attached to a plumbing vent pipe, with a completely open view of the sky here on top of a mountain in Tennessee. 
> Here's what I am noticing:
> To start with I simply turned on the Thunderbolt on Saturday morning without doing a warm or cold reset. Within a few minutes, I was seeing six or seven satellites, with the SV boxes lit up green with various numbers which I assume are satellite ID numbers. When I woke up Sunday I was down to seeing only two satellites. The numbers listed were different than the ones I saw before I went to bed Saturday.  But when I unplugged the AC power from the Thunderbolt and plugged it back in, I was back to six satellites. 
>  I had thought that the GPS satellites I am able to see from my location are fixed 24/7. Do they move and different satellites come into view with rotation of the earth?

GPS Sat’s orbit the earth. Their ground track changes all the time. The WAAS broadcasts are from geostationary sat’s.

> I did a warm reset when I got up at 4:45 this morning and when I got home, four satellites were still green on Tboltmon. About an hour ago I went ahead and did a cold reset. 
> I now have 6 satellites where the SV is green, and one with a yellow SV with a value of 7.0. 

The cold reset took care of the incorrect location you had loaded in the TBolt. They do not come with your location pre-loaded. 

> All critical alarms are green, and all minor alarms are green except position questionable which is yellow. That has been yellow since Saturday. 

Which could imply that your position has not been saved or that the antenna location is not very good. Since the program you are using 
is a bit clunky, you will need to read the manual in detail. 

> Under the Disciplining status, Mode is (0) Normal and Activity is (0) Phase Locking. 
> The Timing Outputs are all over the place and have been since Saturday. Twenty minutes ago I got:
> PPS  -106588.28 ns GPS
> 10 MHz  166.08 ppb
> So far today I have gotten the following ppb readings:
> -41.48
> 374.30
> 0.48
> 0.70
> Should the Timing output variance concern me? 

Either you need a program that will log and plot this stuff for you, or you need to dig
deep into the program you are using.  Either:

1) Your TBolt is broke
2) You still have a location / position issue 
3) Your antenna location is still not very good
4) Your feed line is not up to the task at 1.5 GHz
5) Your antenna gain is not enough for the length of feed line you have
6) Your antenna is broke
7) Your program installation is broke
8) Your serial cable / adapter is broke. 

First thing I would do is to download LH and see how it works with the 
remote TBolt that is connected to it. That will give you a way to see what
a properly operating unit looks like and how the commands all work. Once
you are familiar with a working setup, see what yours looks like.


> Thanks in advance for any help or advice. 
> Chris
> Monteagle, TN
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