[time-nuts] Do I have a defective thunderbolt?

WarrenS warrensjmail-one at yahoo.com
Thu Nov 18 19:13:40 UTC 2010


I was finally able to find your plots.
Note, Your 1000 sec one is 5 times better than your 200 sec which is as it 
should be.

You should download the latest version of Lady Heather beta.
It has the tools to see what is causing your problem(s)

Most likely it is mainly the antenna placement.
Use the "SAS" command and let it run 12 hrs.

Would help if you can get the antenna on the roof
or if not, near the ceiling with a pie pan under it works OK for me.

In this situation the tricks are to set the TC as high as practically up to 
1000
Set the Elevation as high as possible say 45 deg
and set the Level to block weak signals, maybe 3 to 6, depends on the signal 
levels you're getting
Do make sure there is Always a minimum of one or two sat being tracked 
(Blue plot)


Use "JJ" command to reset your Phase error and set your damping to 0.707
Also your Temperature sensor is a low resolution one.

ws

*********************
Geraldo

geraldo
>Is this normal, or do I have a defective unit?

It is normal for a default Tbolt, with any (or all)  of the following:

MultiPath
a poor antenna,
a poor sky view,
a poor location survey
a poor elevation mask setting
a poor Sat Level setting
a poor TC setting
A poor Sat cable

ALL of the above needs to to be corrected to make it lots better.
Lady Heather has all the tools you need to find which ones are effecting 
you,
But I could not see your plots.
If you want more information, post a LH log file.

Have fun
ws

ps The damping should remain at about 1.0

***************************
[time-nuts] Do I have a defective thunderbolt?
Geraldo Lino de Campos geraldo at decampos.net
Wed Nov 17 16:21:20 UTC 2010


I have a thunderbolt acquired from TAPR. Almost every time the number of
satellites change, there is an abrupt change in the DAC voltage - as high as
1 mv, sometimes. See
www.decampos.net\LH\LH1<http://www.decampos.net/LH/LH1>.png
- a graph with time constant 200 and Damping 4. Using much higher values
improve the situation, as can be seen in
www.decampos.net\LH\LH2.png<http://www.decampos.net/LH/LH2.png>, time
constant 1000 and damping 100 (note the change in the DAC scale), but
the jumps are still present.

Is this normal, or I have a defective unit?

The antenna is located in a window, with several buildings nearby, so the
change in the number of satellites is frequent.
-- 
------------------------------------
geraldo at decampos.net 




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