sam. 09 octobre 2021

HP 34970A Data Acquisition Unit - part 6

Quick follow up; I recently got back on this project to try to complete it and fix remaining problems.

The source code for the firmware is available here:

https://hg.sdfa3.org/hp34970-firmware

The Kicad project is available here:

https://hg.sdfa3.org/hp34970-pcb

Making the USBDevice work

As described …

sam. 07 novembre 2020

HP 34970A Data Acquisition Unit - part 5

After a loooong pause on this project, I have recently been able to work on it again. In the previous post in this series, I've started to implement a replacement board prototype based on a an NUCLEO board and an SSD1322-based OLED display.

Meanwhile, I have also almost completely described …

ven. 20 avril 2018

HP8662A Synthetized Signal Generator - Part 3

This is the part 3 on my series about my HP 8662A Signal Generator, and is about the third main problems I found with this unit, as evocated in part 2: Error 04 is lit and there are some very unpleasant spectrums at some frequencies.

Low Fequency Section

If the …

jeu. 12 avril 2018

HP8662A Synthetized Signal Generator - Part 2

This is the part 2 on my series about my HP 8662A Signal Generator. After fixing the PSU, several more problems needed to be addressed:

  • a few sloppy keys on the keypad,
  • the know did not work at all,
  • and more importantly, some very unpleasant spectrums at some frequencies (covered …

sam. 24 mars 2018

HP8662A Synthetized Signal Generator - Part 1

I recently pulled an HP 8662A I bought a while ago from my cellar. I don't remember exactly in what condition it was advertized when I purchased it, but it was most probably advertized as non working (otherwise it would have been cheap enough, more, what the fun in buying …

mar. 03 janvier 2017

HP3562A Dynamic Signal Analyzer

One of my old test gears waiting for my attention in the cellar was a HP 3562A Dynamic Signal Analyzer. Back then I bought this device mainly for doing audio analysis (I was building my HiFi system, mostly based on Nelson Pass' schematics), mainly to display spectrum responses and compute …

mar. 03 janvier 2017

HP3562A Dynamic Signal Analyzer - Part 2

This is the part 2 of the series about my HP 3562A Digital Signal Analyzer, quickly describing the Digital Section of the instrument.

Digital Section

The unit is quite capable, since the main CPU is a 68000 (not exactly of small CPU for the time).

The 8 boards are:

  • A1 …

mar. 03 janvier 2017

HP3562A Dynamic Signal Analyzer - Part 3

This is the part 3 of the series about my HP 3562A Digital Signal Analyzer, quickly describing the Analog Section of the instrument.

Analog Section

The analog section consist in 6 boards:

  • A30: Analog Source
  • A31: Trigger
  • A32, A34: Input ADCs
  • A33, A35: Input

Analog Source

A30 - analog source block diagram

This board is mainly …

mar. 03 janvier 2017

HP3562A Dynamic Signal Analyzer - Part 4

This is the part 4 of the series about my HP 3562A Digital Signal Analyzer, quickly describing the HP 1345A Digital Display unit as well as the repair I had to do on it.

Display

The display unit is a HP1345A Digital Display without the option 714 (wich adds a …

mar. 22 novembre 2016

HP 3456A Digital Voltmeter

A very long time ago, I bought a venerable HP 3456A Digital Voltmeter. Back then, I had no clear idea what kind of device it is; but it was cheap. It worked quite fine (it is indeed not calibrated), but I noticed for a while that it was quite unstable …

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