[time-nuts] Different Survey Results

Bob Camp lists at rtty.us
Thu Aug 19 21:10:38 UTC 2010


A few other things to try / consider:

1) Hit the "auto calibrate" function in LH to calibrate the slope of the
OCXO, it will also load some damping and time constant stuff that you may
want to overwrite. I don't know if this is a "beta only" feature or not.

2) Make sure that the TBolt isn't getting hit with drafts. Something as
simple as a shoe box over it can help things quite a bit. 

3) The +12 supply is fairly critical. Good regulation and low noise help

4) Clear view of the sky to the south (northern hemisphere) or north
(southern hemisphere) helps the antenna a lot. Higher is usually better for
GPS antennas.

5) The OCXO will run quite a bit better after it's been on for a while. How
long depends on the one you have and how long it's been off. A few days to a
few weeks may be involved.

6) Monitoring what's going on with long term charts on LH is very useful to
diagnose specific issues.

Lots of things to play with. None of it likely to cost much, other than some
of your time.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Peter Krengel
Sent: Thursday, August 19, 2010 12:29 PM
To: time-nuts at febo.com
Subject: [time-nuts] Different Survey Results


I'm new to the list and to the themes at all. I'm running a V3 Thunderbolt
using the great Lady Heather Software (thanks for this).

Setting up the tbold for the first time I made a 48h survey. 
To compare the results I also started a SirF III GPS using VisualGPS
software and after the 48h period I got totally different results.

Knowing my real geografic coordinates very well I saw that the tbold
obviously calculated wrong data. 

So my questions to the group are:

1. For getting best disciplining results out of the tbold: Do I better 
    put in the coordinates manualy or using the survey function?

2. Is it necessary to modify DAC and temperature settings using
    command line options (or using the heather) or does tbold work best with

    factory settings?

3. Is there any "How to.." pdf or book on the net which comes with more   
    informations about the tbold experiences than the well known
    official pdf from 2003 ?

Thank you very much for help.

73 from germany
Peter Krengel
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