53132A mod help/info requested

[gab_au]

Hi all,
I posted the following in metrology as an addendum to a reply but didn't get any response to this particular section of the post so I thought I'd try this forum as there may be a different audience.

I have a 53132A with no options fitted. I'm most interested in incorporating a 12.4GHz frequency extender and attempted an EEPROM mod as discussed in a yahoo group. This involves removing the eeprom, replacing it with a socket, and modifying a few bytes. In the process of doing this (long story short) I didn't copy the eeprom first and when I placed it in the socket it got erased or corrupted. I conducted a cal, apart from the time interval fine, and all is OK. However......

The mod is supposed to give access to a divide by 512 but two of the code0/code1 combinations give me divide by 128 and the other two give me no ch3 fitted (the mod isn't doing anything). So either: when I corrupted the eeprom I lost some info; the software version needs to change not just the eeprom, ie the mod doesn't work for a no option counter or pre a particular software version; or the mod doesn't work (which I doubt).

Would anyone have an eeprom bin file from either a no option counter or a 12GHz option counter so I may compare what my eeprom contains (a lot of FF !!).

Also, has anyone installed a divide by 512 option into a no option counter - if so, is there more than the eeprom to get divide by 512? I'm waiting on a plcc to dip adapter to reprogram the eproms to new software. Mine has v3944, there is a v4613 about, so I might try that and see if that opens up the divide by 512.

Thanks
Greg

[texaspyro]

I seem to remember reading (don't know where) that the 12 GHz option was not field-upgradable and that there was some motherboard tweaks needed for it.

I bought 3 and 8 GHz channel 3 boards off of Ebay.  The 8 GHz board supposedly works to 10 GHz.  Note that it is not as sensitive (-10 dbm?) as the 3 GHz board.  I don't have anything that goes to 8+ GHz to test it with.  It cost around $60.

I did upgrade the firmware on mine to 4613 (?) from 3xxx in order to get comma separators in the decimal digits (rom images are on the forum somewhere and on ko4bb.com).  The firmware upgrade requires a re-calibration.  This led me to build the 531xx calibrator board mentioned here:

https://www.eevblog.com/forum/metrology/calibrating-53132a/

I FINALLY got in the circuit boards for the calibrator.  It seems to be working quite well.  I do have to re-do the PCB to match the rotary switches that I got in (which were different from the original samples I got).  The new board will also be 1mm thick so that 50 ohm impedance traces are doable.

[TheSteve]

Are you using the same divide ratio as the stock 12.4 GHz option or are you changing it? I guess I am wondering why an eeprom mod was needed. As texaspyro mentioned there are some really old hardware revs that don't support the 12.4 GHz unit. I believe older firmware does not support it as well. It is all documented by HP/Agilent in service notes and the service guide.
I'd try to read an eeprom for you but I've sold all of my 53132A's.