Tom, Unfortunately, it would appear that there is an 'older' version of circuits (?CLIP as well).
My Osc Support Board for the Opt 010 version of the 10811 is a 53132-60011 which is populated with a number of components that are not present on the 53132-60016 board, the board that seems to be used with my (S/N 3736Axxxxx) 53132-60014 Main Board. The 53132-60011 Osc Support Board connects to a 531332-60010 Time Base Output Select Board. On my unit, there are holes in the side panel at the rear of the right side (as viewed from the front) that would appear to mate with the 53132-60010 board and there are unpopulated connections that would appear to mate with the connections from the 531332-60010 board. I can find no mention of the 53132-60010 board in any of the manuals I have. It has a DPDT relay on the board, a couple of voltage regulators (317M and 78M05) and a MC1413D chip, a High Voltage, High Current Darlington Transistor Array. There is a connection from the 53132-60011 board and two connections that appear to connect to the Main Board. I have pictures of the boards if anyone is interested. I wonder if this is what Rick is referring to and that the 53132A might have been modified later to use the 53132-60016 board and an 'updated' Main Board. And, perhaps, better performance? It would be nice if anyone had an older version of the CLIP (or 53132A) that might explain this. Thanks. Joe -----Original Message----- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Sunday, April 12, 2015 11:50 AM To: Discussion of precise time and frequency measurement Subject: [Bulk] Re: [time-nuts] Ultra High Stability Time Base Options for 53132A Hi Rick, It is our good fortune that some years ago Agilent/Keysight released the schematics to the 53131A/53132A counters: http://literature.cdn.keysight.com/litweb/pdf/5989-6308EN.pdf Have a look and see if you can recreate the details that you remembered. I too have noticed on some tests that the counter seems to ruin the benefit of a good external timebase. This is even more true of the newer 53230-series counters. Maybe get rid of the PLL and use a int/ext toggle switch like the 70's. So it would be nice if you or other circuit experts on the list could point out the flaw(s) -- I'm sure a couple of time nuts would even be willing to mod their 53132A boards based on some suggestions on what to try. Thanks, /tvb _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
