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

GandalfG8 at aol.com GandalfG8 at aol.com
Sat Nov 1 17:03:42 EDT 2014

Well, I'm happy to report that Arthur's modification does do the trick,  
although I don't know why as I don't have any data for the interface  as yet.
I daren't disturb the 15 pin connector right now as this  Z3811A PCB is 
still out of its case and connected to a breadboard  with wires just pushed 
into the sockets, and for the same reason I don't have  any computer connection 
at the moment either.
My implementation isn't quite as described, in that I've not made a  
connection to the fault LED but am just manually pulling that input high and low  
on the breadboard with another wire link as required.
Whether or not this is part or all of the reason that my green "on"  light 
is flashing rather than steady I don't know, but I am seeing the 1PPS and  
15MHz outputs and the 15MHz looks to be conditioning ok.
Aside from the 5 volt supply, which I'm picking off from pin 5 of the  
header between u33 and U34, and the aforementioned fault LED connection, all the 
 other connections can be made to J5 externally and could be housed in a 15 
 way shell along with the switching circuits.
I'm still hopeful that some cross linking of the right pairs might  achieve 
the same result without the extra circuitry, so "all" that needs to  be 
done now is just to identify the right pairs:-)
At least with it up and running it should be easier to check out some  of 
the inter-unit signalling.
Thanks Arthur, your efforts are much appreciated.
In a message dated 01/11/2014 15:25:02 GMT Standard Time, aroby at antamy.com  

For  those who missed it, Arthur's post is at  
https://www.febo.com/pipermail/time-nuts/2010-June/047825.html and the photo  is at  


-----Original  Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf  Of Arthur 
Sent: Friday, October 31, 2014 9:20 PM
To:  time-nuts at febo.com
Subject: [time-nuts] Lucent KS-24361, HP/Symmetricom  Z3809A, Z3810A, 
Z3811A, Z3812A GPSDO system

Bob Stewart bob at  evoria.net
?? ? I have both of my units sitting on the bench. I found that  I needed 
to connect them together to get the REF1 unit to come out of standby  ? . ??

Bob Camp kb8tq at n1k.org
??I suspect that somebody will have  to figure out what the 15 pin 
connector / jumper is doing. On previous RFTG  units there was a way to re-wire the 
crossover interface to fake out the slave  detect process. That would let 
you run a single GPS equipped box and have it  behave correctly. Without the 
fake wires trick none of them played nice  without the slave being present ? 
.  ??
Reposting what I had posted  over a week ago, in case you missed it ? .

Arthur Dent golgarfrincham  at gmail.com Wed Oct 22 13:59:48 EDT 2014  ?? ? 
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 sequence on warm-up and the 
second unit isn't needed at all ? .  ??

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