Hi Dave,
On 8/23/2014 3:51 PM, Dave M wrote:
Thanks for that suggestion, Ed. After a bit of reading in the X72
Reference Guide, it appears that the X72 does have a 1PPS input. That
would be considerably easier than trying to interface the Rb into the
GPSDO. Still trying to understand what the manual is telling me. Next
thing is to determine if my unit has that option enabled (firmware
option). That will be a chore for after the holiday... really busy
next week.
What would that (1PPS disciplining) do for me... in terms of
maintaining the Rb frequency accurately set? Would it be as accurate
as having the Rb disciplined via the EFC input?
It's kind of overkill, but by connecting the 1 PPS from the NTBW50AA to
the X72, the X72 will be disciplined to the 1 PPS so the frequency will
be accurate. The question is how well will it be disciplined, i.e. what
will the Allen Deviation graph look like. I have a few X72 and SA-22c
(X72's cousin), but none of them have that option. I don't know of any
published data on it. Maybe you can tell us how well it performs.
In general, I just don't see the point of disciplining a Rb standard to
GPS. I don't understand what will be gained by doing it. I have a
Z3801A and a Tbolt plus a free-running FRK as a house standard. I
occasionally compare the FRK to the Z3801A but the drift is so low
(~1e-12 per month over 9 months) that I see no reason to link them.
One exception that I recently discussed on another forum was a guy who
lives in a ground floor, north-facing condo. He might need to have a
disciplined Rb standard due to poor GPS visibility.
Ed
Thanks,
Dave M
Message: 5
Date: Fri, 22 Aug 2014 16:19:45 -0600
From: Ed Palmer <[email protected]>
To: Discussion of precise time and frequency measurement
<[email protected]>
Subject: Re: [time-nuts] EFC info on Trimble 34310-T OXCO
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Have you checked your X72 to see if it has the 1 PPS discipline
option?
That would be a lot easier (and probably better) than your proposed
transplant.
Ed
On 8/22/2014 12:39 PM, Dave M wrote:
Does anyone have any info on the OXCO in the Nortel/Trimble
NTBW50AA-17 GPSTM receiver? The OXCO is labeled as Trimble 34310-T.
I see some Trimble 34310-T oscillators on Ebay with pinouts labeled,
but no other info.
Specifically, I'd like to know the EFC characteristics for it. I'm
thinking of the possibility of pulling the OXCO out of the GPSTM and
subbing in a 10 MHz Rubidium, and using the GPSTM to discipline the
Rubidium. My Rubidium is a Symmetricom X72, recently purchased. It
seems to be working well.
Does anyone know the differences between the three OXCOs used in the
GPSTM receivers ("T", "T2" and "Oak")?
Thanks for some insight,
Dave M
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
