[time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...

GandalfG8 at aol.com GandalfG8 at aol.com
Wed Oct 22 15:09:30 EDT 2014

Hi Arthur,
Thanks for the photo, I was just going to play it by ear but it's  always 
handy to have a starting point.
I did take a look back at June 2010 and eventually found your RFTG comments 
 under a discussion on the Z3815A, so might be why I didn't recall seeing 
them  previously, and that month being a busy one some quite heated  
discussions might have offered further distractions:-)
I'm running a fair bit of 5MHz kit here already and didn't  think I really 
needed these when I first saw them a few months ago but in  the end that 
price was just too good to resist, even including  international shipping and 
UK taxes.
Perhaps the realisation that the going rate for used MTI 260s alone seems  
to be $30 and upwards these days might also have had something to do with  
In a message dated 22/10/2014 19:23:32 GMT Daylight Time,  
golgarfrincham at gmail.com writes:

GandalfG8 at aol.com GandalfG8 at aol.com
Wed Oct 22 04:35:40  EDT 2014

"Similarly, with this RFTG-u kit I'd be more inclined to look  for  ways of
routing the native 5MHz from the GPS conditioned Milliren  260 series
oscillator to the outside world, and to just treat any other use  found for
processed 15MHz as a  bonus:-)"


This was kind of my thinking on  trying to use this Lucent unit as well.
Way back on Fri Jun 11 16:48:43 UTC  2010 I posted about using one of
these units I had modified but at the time  there wasn't a single person
who was interested. I have been using the  RFTG-u REF1 since then and
it is a nice unit. The modifications I added  (including a power supply
-see photo) allows the lights to cycle through  their normal secquence
on warm-up and the second unit isn't needed at all.  I can't give you
any reason why I used the general purpose transistors  instead of a
single IC quad inverter which might have worked as well or how  I
stumbled upon why I did what I did back then but it does work.  Here's
what I posted to Time-Nuts 4 years ago.

"Like most Lucent  units the RFTG-u REF1 was made to run with another
back-up unit for  redundancy, needed an interconnect cable, and has no
information available.  I managed to figure out a way to make it work as a
standalone unit and ran  the 5Mhz from the OXCO thru a QBits amplifier to
give me 5Mhz output  instead of the Lucent standard of 15Mhz. I haven't
carefully checked it  against the other GPSDOs I have running but with the
modifications I made  to allow it to work solo, it seems to be a pretty good
plug-and-play  unit."

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