[time-nuts] Upgrading TS2100 from TCXO to OCXO

Robert Watzlavick rocket at watzlavick.com
Thu Mar 31 13:24:17 UTC 2011


I changed the root/eng/timing/offset parameter from -100 to 0 on my unit 
and let it sit overnight.  This morning, it is locked and without a 
frequency offset.  So I wonder why my unit would have had a 100 ns 
offset programmed into it?  I cannot figure out how to get the 0 value 
to stick though.  When I power cycle it, it returns back to -100.

I programmed various values into to the info field, restarted the unit, 
and read the following results for the offset parameter:

0x00000000     -5
0x00000010     -5
0x00000021     -5
0x00000022     -5
0x00000024  -100
0x00000028     -5

This is interesting for a couple of reasons.  First, it matches what 
Jason is seeing in his units with the -5 ns value for offset.  However, 
a different TS2100-IRIG unit I looked had an info value of 0 and its 
offset was also 0.  Maybe the presence of the GPS unit makes it think it 
needs an extra offset?  We know that bit 6 is used for GPS vs. UTC for 
the NTP time (from the manual).  I suspect bits 2 and 5 are for GPS 
since my unit was delivered that way.  I would think at least 2 bits 
would be for the osc type but which ones?  And if Jason's unit came 
delivered as an OCXO, why aren't any bits set to signify that?  Maybe 
the TCXO/OCXO is one configuration and the Rubidium is another. It 
someone had a factory configured Rubidium unit, it would be interesting 
to know if there are any bits that correspond to it.

-Bob

On 03/30/2011 08:40 PM, Robert Watzlavick wrote:
> My unit (TCXO/GPS originally) has the root/eng/timing/offset set to 
> -100. A TCXO-IRIG unit that I looked at has an offset value of 0.  
> When I was first bringing up my unit with the OCXO, I was comparing 
> the 10 MHz output against a stabilized Thunderbolt and I noticed the 
> TS2100 EFC voltage seemed to stabilize but there was an offset in the 
> 10 MHz output.  The lock LED wasn't turning on either.  I got 
> impatient and started poking around and that's when I noticed the 
> "offset" parameter was set to -100.  I changed it to 0 and the lock 
> LED immediately turned on but then the EFC started heading the other 
> direction.  I put it back at -100, let it sit for a few hours, and it 
> eventually locked without a frequency offset.  I'll set my offset back 
> to 0 and see where it ends up overnight.
>





More information about the Time-nuts_lists.febo.com mailing list