[time-nuts] Lucent KS-24361 GPSDO arrived today several questions

GandalfG8 at aol.com GandalfG8 at aol.com
Thu Nov 6 03:44:27 EST 2014

Hi Paul
Prime question is what are you calling the "slave" unit?
In normal use Lucent treats the Ref-0 unit as the master and Ref-1 as the  
slave, but it's Ref-1 that contains the GPS module. Bit confusing but if 
you've  got Ref-1 with the GPS module then you're in business:-)
It's turned out the transistor delay circuit isn't needed after all and the 
 wiring can be simplified too.
All that's necessary to run the Ref-1 stand alone is to ground pins 2 and 3 
 on the J5 interface connector and there's a couple of convenient ground 
pins  already on that connector, 8 and 13.
In normal use pin3 is tied hard to ground, presumably via direct link from  
the other module, so that can just be a wire link to either pin 8 or 13.
Pin 2 is normally held at a logic low level so although a direct  ground 
seems to work ok for that too, and no damage noted so far, I prefer to  play 
it safe and ground that one to the other ground pin via a 470ohm resistor,  
which also works fine.
That's it.
The LEDS should flash at start up, followed by "No GPS" and "Fault" on  
solid whilst the unit goes through acquisition and lock, this can take  an hour 
or so, and then those LEDs should go off and the "On" light should  be 
At this point the 15MHz and 1PPS outputs are enabled.
The J8 diagnostics connector is enabled from start up and SatStat can  be 
used to monitor progress.
The RS422 3 wire fudge suggested by Stu Cobb works fine for me, J8 pin 7 to 
 PC 9 way comm port pin 5, J8 pin 8 to comm port pin 3, J8 pin 9 to comm 
port pin  2.
In a message dated 06/11/2014 01:24:33 GMT Standard Time,  
paulswedb at gmail.com writes:

I have  been following the threads on the KS-24361 some of the longest I
have ever  seen on time nuts.
So I have a very basic question.
There was a 2  transistor delay circuit by Arthur way back. I believe this
is  needed.
But then the pin numbers seem to get a bit mixed up and there are  some
jumpers with several comments.
Is there a clear guidance on what to  do? I do not have the slave unit.
Power is not an issue.
Thanks in  advance for your help.
Must say the units very  nice.

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