Power Supply Hum
Things that make you go hum… Or maybe bonkers. I have a Astron RM-50A that I have been using to power two Motorola units that I use for VHF/UHF. Yes, overkill, but I have been planning on putting it in a console that will also house my Seinna and my Icom IC-746Pro.
This last week I finished constructing the console, so now comes the fun part of taking everything apart and putting it back together. Since I got the PS, it has always had a pretty annoying hum to it, so I thought now would be the time to work on it.
I took the cover off of it, dreading the possibility of what I would find. I have read too many Amateur Radio horror stories about de-laminated transformers and such. You know, best to just pretend it doesn’t hum. Anyway, I found the transformer to be in decent shape, so I checked the nuts and found a few loose and one on the big capacitor missing. I tightened them up and replaced the missing one.
It seems to be better, but I do still hear some hum when it is on. The top cover really deflects right over the transformer when I first turn it on. It doesn’t help to apply pressure to the top cover, so I don’t think that is it. I guess I will just see what happens.
BTW, I did let the capacitors discharge before working on it. That’s why I am able to make this post.