3458a updates and drift checking

[EE4all]

Here is my take on the 3458a updates.

I have replaced:

-Inguard supply electrolytic capacitors
-Outguard supply electrolytic capacitors
-Line filter
-Rifa capacitors
-Added sockets
-Settings FRAM installed
-Firmware updated
-Added option 001 memory

*The ZIF socket required moving 1 resistor and 1 capacitor to the underside of the board. I will be doing various projects with this one, so wanted the cal RAM easy to swap.
*The cal SRAM has been backed up to PC

To Do:

-New fan
-Put labels on the firmware chips on top of the aluminum window covers
-Source a fuse binding post that is missing
-FRAM board for the cal socket, or just punt and put a new Dallas SRAM in for now Installed via a socket adapter
-5000 different volt nuttery tests and  fun times starting with drift tests
-To be continued...

Look at the date code on this old Dallas chip.  It's still holding the data.

[EE4all]

Calibration SRAM replaced with FRAM and stacked socket adapter. I used 26 gauge magnet wire "inside" the adapter. The 28 pin FRAM socket has extra tall pins, so this gives the bit of space needed. I might have some boards made at some point but this works quite well.

[IanJ]

Calibration SRAM replaced with FRAM and stacked socket adapter. I used 26 gauge magnet wire "inside" the adapter. The 28 pin FRAM socket has extra tall pins, so this gives the bit of space needed. I might have some boards made at some point but this works quite well.

You can download the gerbers for my Cal board Pcb, see the video description of my video below.
There's a couple of different versions depending on whether you want to use an SMD or TH FRAM IC.

https://youtu.be/cAA1TCvwhuw?si=qWiON_Jy2flO4Ut3

Go to @5:37 for the Calram

EDIT:
Just incase anyone asks, my 3458A was built in 2000 but I replaced the front panel with a new one from Keysight UK a few years ago. I still have the HP branded front panel.

Ian

[EE4all]

Thanks, Ian! I had already downloaded your files for this actually, and I will get a few made. I was anxious to get the FRAM going in the meantime with supplies that I had on hand.

Now I will leave it running, as I have no idea how long it was unpowered before I received it.

I will begin logging some data soon, and have your WinGPIB set up as well.