[time-nuts] Lady Heather newb questions

W7SLS w7sls.scott at gmail.com
Sat Dec 16 16:22:56 EST 2017


Mark,

Thanks.  I think I got it:  

> Tcor, UNC

Lady Heather happily posts cryptic messages from the device!

> TFOM, FFOM

Yup, I found them in the Z3801A manual.

Appreciate the help.  Will look for (maybe I have) the (or a) Symmetricom manual.

Scott


> On Dec 16, 2017, at 10:55 AM, Mark Sims <holrum at hotmail.com> wrote:
> 
> Generally the best way to figure out what some cryptic Heather parameter is is to consult the manual for the device and see if you can find something similar to the label... you do have an extensive Symmetricom GPSDO manual, don't you?  ;-)     If Heather sees a wiggly value in a message , it tends to get plotted. 
> 
> UNC is the holdover uncertainty... how much the time is expected to drift over 24 hours without signal.  The value should go down as the GPSDO learns the oscillator behavior.
> 
> TCOR is,  uhh,  tcorr.  Yeah, that's the ticket... obvious...   It's some value in a status message that wiggles around.  It shows up in a status message with the header "TEMP COR".   I assume it's the frequency adjustment made due to temperature.
> 
> TFOM and FFOM are pretty standard GPSDO parameters.  Time figure of merit and frequency figure of merit. I think the telecom industry sort of standardized them.     The HP Z3801A manual talks about them.     
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