Building a bench 10MHz reference: part 1
Many electronics test equipment need an accurate time base. Most often, it's build on a 10MHz base.
For quite a while now, I have a used rubidium frequency and time reference (Efratom Model LPRO-101) waiting for a nice enclosure. I also have a small Extron Electronics video signal amplifier I …
Tektronics 2445 scope PSU repair: part 1
I've recently took my good old Tek 2445 scope from the cellar (along with my {tag}HP8904A signal generator), and it showed signs of tired PSU: unstable display, noise, then the typical noise of a capacitor failure.
Here is the beast:
![My old Tektronics 2445 scope](https://whatever.sdfa3.org/images/tek2445/tek2445.jpg)
And some pictures of its womb:
![The main analog board.](https://whatever.sdfa3.org/images/tek2445/tek2445_A1.jpg)
![Top view of the scope.](https://whatever.sdfa3.org/images/tek2445/tek2445_top.jpg)
The PSU consists …
Updating the Prologix USB-GPIB firmware on Linux
Prologix sell several low cost GPIB controllers. I have one their old deprecated dongle "GPIB-USB Controller 4.2" and had fun with it with my pygpibtoolkit project.
It's a very simple dongle consisting in an Atmel ATMega164P microcontroller and a FTDI FT245FL chip for the USB<->RS232 convertion.
![The Prologix GPIB-USB controller.](https://whatever.sdfa3.org/images/prologix/prologix_4.2_small.jpg)
Unfortunately, it's …