Let’s do some work to this PACO C-20 R-C Bridge
Monday, August 24, 2026 at 07:49:21
I picked this bridge up at the Columbus Hamfest in August 2026. It’s fully operational, but I wasn’t thrilled with some of the work done to the unit.
In particular, the wrong type of capacitor was used for the across the line capacitor, and I didn’t like the way the filters were laid in. It also needs a new power cord.
The ACL capacitor is there because most don’t have the correct part laying around in stock. These are essential if you’re going to be working on this kind of equipment, get a few and put them in your parts bin. The filter capacitors are they way they are because the person probably didn’t have the correct voltage part, so he made one by putting two in series. That, of course, has the same effect on capacitance that resistors in parallel has, but it adds the working voltage together. It’s not the best way to do this, but it works and will continue working as long as you’ve sized parts properly and tried to keep some sort of balance.
I was originally going to replace the other filter as well, but it’s fine, and is properly rated even if it’s a higher value capacitance. It’s not going to hurt anything, and it’s likely the original part probably wasn’t anywhere near the actual value printed on the shell. That’s just the way older electrolytics worked - they were plus whatever minus something in value.
Let’s start with the electrolytic. Here’s a nice new 10μF @ 600VDC laid in. The original was 8μF @ 600, so this one is fine and won’t cause issues.
The ACL capacitor is similarly replaced with the correct type of part, and coated with ‘lectric sketti for safety.
And, of course, a new power cord is routed through the chassis, tied with an underwriter’s knot.
This guy is ready for service.
Previous part of this series: https://wereboar.com … aco-c-20-r-c-bridge/