An EICO 242 FET VOM Part 4: More capacitors
Monday, September 28, 2026 at 09:10:54
There are four more capacitors in the EICO 242 I’d like to replace before doing a calibration on it. Those are:
The main AC filter,
The two capacitors in the AC rectifier circuit,
The main AC input blocking capacitors.
There’s not much else to say, let’s get started.
First is the AC blocking capacitor. It’s a hefty part, 0.1 @ 1600VDC. I have some new 2KV parts for this.
This one was kind of a pain in the butt to get out without messing up other wires.
Next is the main filter. This was a matter of unbolting the board, unsoldering the capacitor, and replacing it. Not really that bad. It’s not defective, but it’s 50. Let’s get it out of there.
The old part is a 300μF @ 30V. I have 470μF at 50V. Now, this device has that as well. The old part was closer to 400μF, so we’re not far off from the new one at 460μF measured.
The last part(s) are the capacitors in the AC rectifier circuit. There are two, both 0.027μF ceramics. There’s also some diodes that I had to heat up to remove the capacitor.
Those diodes look like crap. I’ll re-do those at a later date.
Next up is the calibration. There are a few resistors in there that are off, so it’s not going to be 100% across all ranges. We’ll get to that at a later date. Stay tuned!
Previous part of this series: https://wereboar.com … m-part-3-capacitors/
Next part of this series: Coming soon.
Wrapup and final thoughts: Coming soon.