[time-nuts] FE-.5680A trimming resolution
albertson.chris at gmail.com
Mon Jan 30 14:52:05 EST 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
The data looks noisy on LH's graph because of the scale of the graph.
Compared to the 1PPS it is a smooth function.
Redondo Beach, California
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