[time-nuts] Thunderbolt? (re simple gpsdo.)

[Attila Kinali]

On Fri, 30 Dec 2011 22:54:26 -0800
Chris Albertson <albertson.chris at gmail.com> wrote:

> I don't count anything with a computer and software inside as
> "simple".   My definition of a simple device is a capacitor or a
> transistor or I guess a single flip-flop or op-amp.   A simple
> controller would some how use about two dozen or less of these kinds
> of components.

I think, then the simplest solution is to use a LEA6-T, programm
the second timing output to 8MHz (not 10!), and use a PLL and you
get a GPSDO like the one James Millerd designed a few years ago, based
on the Jupiter GPS.

Here, the only time you need a computer is when you configure the LEA6-T,
which can be done using USB or a serial port and the config can be stored
in the EEPROM of the LEA.

AFAIK the bigest catch here would be the update rate of the timing
solution of the LEA and the introduced phase glitches. From what i
know, the LEA provdies two modi for the freqency output, one is
phase locked to the 1PPS, and the other is frequency locked.
This together with the low update times, will require long integration
constants for the PLL loop, which might make the thing problematic.


			Attila Kinal

-- 
Why does it take years to find the answers to
the questions one should have asked long ago?