TonyG's HPAK Test & Measurement Equipment

In this video, I go through the last piece of troubleshooting to get the rails in spec and then exercise the meter using the 8477A Calibrator.

Going back to basics and checking the power rails leads to an "alive" unit - We're one step closer to getting it back working.

After 5 attempts and a complete machine reinstall, I managed to get Premiere Pro to actually create the video properly. The TL;DR; on the video is that a fair chunk of the not working A2 board actually works but there are root problems that I need to go back and address.

I decided to remove the old potentiometer while I was waiting for the new one to be delivered today - It appears I jumped the gun on the guilty part...

In this video, I take the lousy potentiometer from the HP 432A Parts Mule and disassemble it for a good cleaning.

This is a quick part 2 video in the series I'm doing on repairing the HP 432A. We'll take a look at whether the A1 board actually works and at the proposed replacement component.

In this video, I'm looking at a broken HP 432A Power Meter (it can't zero) to see where the fault may lay - Hopefully, it'll be an easy fix in Part 2.

I grabbed a Huzzah32 to hook up the LCD and test/identify the segments - Here you can see that some segments come through nicely and some are faint. I'm still not convinced that the issue is with the LCD itself, not the MC145000P controller chip. Anyway, I now have an XLS with the segments in it so I can start working on reading the data from the plotter before moving on to displaying it on a new display.

A quick look at the LCD panel of the HP 7090A Measurement System Plotter. I took the LCD panel off, cleaned the zebra strips, and reassembled it. I'm a bit conflicted but I'm leaning toward replacing the strips. Though I will need to measure the voltage on the output IC just to be sure.

Having the pen selection & Geneva wheel issues addressed, I wanted to try some more detailed plots. This video is in real time so the first plot ends at 3:50 and the second at 7:12. Code is available at https://github.com/TGoodhew/HPGLTest. Chapters -------------- 0:00 First plot 3:50 Flipping the paper 4:14 Second plot 7:12 Plots complete

My 7090A broke while I was working on the 83522A so I had to switch over to address it - The Geneva wheel had broken and the rubber pen caps in the carousel were sticking to the pens pretty badly. I posted about this on the EEVBlog - https://www.eevblog.com/forum/repair/hp-7090a-measurement-plotting-system-329125/msg4239913/

The problem has been fully diagnosed but, as you'll see, can't be immediately fixed. Hopefully, it can be brought back to life in the future.

I wanted to check the power level output and how it swept across the frequency range but, strangely enough, I only have one spectrum analyzer - here is the solution I came up with. Skip to 12:33 to see the results. Code available at https://github.com/tgoodhew/gpibutils

I have a couple of 8350B mainframes and some plug-ins - I don't know if any of the pieces work and what leaped to mind was the only saying about a man with two clocks never being sure of the time. Let's take a look at what I have.

Still trying out rumble upload features

I'm just testing the rumble upload process

Testing some video upload stuff

This video is a little different from the usual ones. My friend Miguel works for an OEM calibration lab so I thought we discuss how he got there and what the difference is between 1st and 3rd party labs. We also take a look at a couple of the racks in his lab - You can jump to around 31:00 if you want to watch just that.

I realized that for some reason my multi-cam edits didn't show the values from the SWR readings. I just switched to Premiere Pro so I'm apparently still learning it.

In this video, I'm joined by my mate Miguel to have a look at the precursor to the modern VNA, the 8508A Vector Voltmeter and a general chat while doing so. Miguel is an old Navy guy so I cut out as much of the salty language as I could so I hope you enjoy this. I'll be following up on this video with a talk about cal labs I did with him soon.

In this video, I take a look at the classic 5343A Microwave Frequency Counter. This unit can measure frequencies up to 26.5 GHz and uses a heterodyne harmonic architecture.