Hi The purpose here is to estimate the stability of a GPSDO. For that, you don't need "perfect". You simply need to get the Rb close enough that it's error is manageable. Bob On Sep 18, 2013, at 8:18 PM, Azelio Boriani wrote: > The GPS's PPS wanders but it can be used to have an idea whether your > Rb is fast or slow.

For each round I make I discover more, such as the minimum square loop that estimates the linear drift. Tossing the code into a 68k emulation would be possible, but there is a bunch of things to simulate in it which relates to the hardware.

From the self-calibration and the timing estimates we got from the synthesizer, we guestimate that the largest bin is approximately 140ps in size. Our measurements have been done using an SR620 with an trigger signal generated by one of the nodes with a rate of 10Hz, about 5us before the pulse.

short-circuit measuring resistors: A6 pin 5- 6 188mV, 0.07R 3% -> 2.68A +5V A6 pin 7- 8 498mV, 0.07R 3% -> 7.11A -5.2V A6 pin 9-10 109mV, 0.4R 1% -> .2725A +15V A6 pin 11-12 55mV, 0.4R 1% -> .1375A -15V Since I measured this on the bottom of the motherboard, the contact and PCB trace resistance to/on A6 is also included so these currents are high estimates

The standard error on estimating the standard deviation is ~ +- 5% for 200 samples. So loosely speaking in the neighborhood of 100-300 bins the resulting adev will have an rms uncertainty of roughly 5%.

If I use the zener test current in the data sheet and the max current of the load, I end up with about the same value the calculator estimates. But if I use a lower value of zener current and a lower drain from load I end up with a value pretty close to what may have been in there originally.

I could only afford a single Accutron, so I got in the habit of storing it overnight in an orientation estimated to correct bedtime error by wake up time. I got pretty good at it. BTW thanks very much for the tip on the book- I must definitely get a copy.

What the box will give you is a frequency estimation assuming doppler free conditions. If you want to do smarter things, you need to pull the data off the counter in binary form and post-process it yourself. The programmers manual for the HP5372A is a great teaching tool for how these beasts process stuff.

Then it still remains to validate the correction for offset, which you can do in laboratory clocks, you intentionally vary the magnetic field to monitor the slope of the frequency shift with magnetic field and you can get the needed corrections to correctly estimate the offset from 0 magnetic field conditions.

.) -- It's funny - folks have spent a lot of time over the years making oscillators that are "on frequency" - but with modern processing techniques, a lot of times it's more about "good phase noise close in" and "a way to measure and estimate the frequency" (the latter requires decent ADEV if you're not making the measurement simultaneously) but no real