[time-nuts] FE-.5680A trimming resolution
Chris Albertson
albertson.chris at gmail.com
Mon Jan 30 19:52:05 UTC 2012
On Mon, Jan 30, 2012 at 10:43 AM, Mark Sims <holrum at hotmail.com> wrote:
>
> These are 4-BYTE single precision floating point numbers, not 4 bit integers. They are the values plotted in the Lady Heather PPS and OSC graphs....
Sorry I type faster than I think. You are right they can't be four bits.
I work in rocket telemetry, you'd think I'd get this straight. I
write software to unpack this kind of stuff.
> A much better approach is to minimize the system errors with a GOOD antenna, accurate position survey, proper oscillator control parameters, and temperature stabilization (of both the receiver and power supply)... Lady Heather is willing to oblige on the last points. A good Tbolt implementation can get the PPS plot to under a few nanoseconds of error.
I've done this. I see values in the single digit nanoseconds. I have
a timing antana on a mast on the roof. Perhaps I could get a better
timing antenna and low loss coax lead. LH reports the signal at 40dB,
+-2dB. Is that good enough?
I've seen adev plots from an Oncore MT12
(www.leapsecond.com/pages/m12-adev/) where these error estimates are
added in or not and they get maybe 20% better with the corrects
applied. the MT12 produces error estimates about that same size as
a T-bolt.
The data looks noisy on LH's graph because of the scale of the graph.
Compared to the 1PPS it is a smooth function.
Chris Albertson
Redondo Beach, California
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