[time-nuts] Jackson Labs Fury & Isotemp OCXO134-10

[Matt Osborn]

On Sun, 02 Nov 2008 01:28:34 -0500, Matt Osborn <kc0ukk at msosborn.com>
wrote:

Hi all,

Thanks for all the help and ideas with the IsoTemp/Fury combination. I
followed Hal Murray's advice fired up the combination yesterday (its
been running for about 24 hours now) and everything is working as
advertised.  The IsoTemp locked in with an EFC of 4.523xxxx and today
is down to 4.498xxxx volts and falling slowly, so it would appear that
boosting the Fury EFC range won't be necessary.

Bruce Griffiths suggested a 1.6 gain buffer amplifier and Jim Miller
had designed that exact amplifier to boost an EFC range of 0 - 5v to 0
- 8v specifically for the IsoTemp OCXO134.  Jim had a PCB available,
so I ordered it and will build that up if the IsoTemp starts aging in
the wrong direction. I believe that problem has been addressed.

I've not yet solved the power sequence problem (if it exists); I'll
follow Said's advice and just try powering both from the same supply
and see if the Fury reset hold time is sufficient.  If not, I'll
pursue Jim Hall's MAX6819 approach. That would seem to be a simple and
inexpensive  solution.

Now I'm trying to understand Bill Jones' GPSCon program and what it is
telling me about the Fury GPSDO.  With some history provided by GPSCon
and a better understanding of just what, exactly, I should expect to
see and to strive for, I will apply Said's suggestions and see what
develops.

BTW, it would appear as though my HP 53131A counter reads 220 mHz low
with a 2 second gate time.  There appears to be no appreciable drift;
it always reads 220 mHz low.  I'm sure there is a name for that
measurement, I hope to learn it soon.

Thanks to all for your help. I'm amazed at the high signal to noise
ratio on this list.

-- kc0ukk at msosborn dot com