Admiral 20B1 Combo restoration

[holmesuser01]

Hope there's room for the new capacitors. There's plenty of room under the hood on the DuMont, so I used regular radial lead capacitors and anchored them in place.

[Phil Nelson]

For the record, feeling caps to see if they're hot is not a scientific (or reliable) method of testing whether they are good. If you have ever watched a power transformer burn up before your eyes -- ask me how I know this -- you will be very careful about powering up with 50-year old or 60-year old electrolytic caps in your power supply.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[Kamakiri]

Originally Posted by holmesuser01

Hope there's room for the new capacitors. There's plenty of room under the hood on the DuMont, so I used regular radial lead capacitors and anchored them in place.

There's a ton of room to route caps under the chassis of this set.

SwizzyMan, you do good work, but there are no shortcuts on something like this. On a 1940s/early 50s set, you *have* to start by recapping the whole thing, then work from there. Even if for some reason the old wax caps and cans are good, the chances of the set being a reliable performer are close to zero....let alone the damage that might be caused.

At this point in the set's life, you are doing something the engineers never designed the set to do....operate after 60 plus years. You have to throw the diagnosis and repair paradigm out the window until after all the caps of every style are replaced (except micas, which are fine about 90% of the time). I usually replace all resistors with a value of 5 watts and over, as well, before the first power up.

[SwizzyMan]

Will be sure to restuff those filter caps Saturday and then continue troubleshooting my current raster imperfections. I do hope you all knew that I had no intention to ever leave those filter caps in. But now that I know there is hope I can continue. I think I am just going to restuff the electrolytics instead of route them under the chassis, I have a particular fascination of sawing the filter caps off and seeing how bad they have deteriorated over the years. Also thanks for the advice kamakiri!