An EICO 249 VTVM, Part 4b: More resistors for the range switch.
Wednesday, July 22, 2026 at 13:10:50
There’s a lot of resistors on the range switch of this device, and that’s really the reason I was putting off the rebuild. It looked quite daunting, but so far (once I figured out how they were referencing terminal names) it’s been going fairly quickly.
For this part, I installed the remaining resistors on the bottom deck, save the parts that are flying off the switch - those will come later. Since most of these are odd values, I had to make a few, including the 9MΩ, and 900kΩ. These were made from paralleling two 18MΩ for the first, and series of a 750kΩ and 150kΩ for the second. The other parts, I was able to get as is.
I’m going to try and finish the upper deck in one go and then start on the main body of the unit. Stay tuned!
Next part of this series: Coming soon.
Previous part of this series: https://wereboar.com … s-start-the-rebuild/
Wrapup and final thoughts: Coming soon.
References
Manual set: https://wereboar.com … with%20schematic.zip