Restoration Commences on 1947 RCA Victor 721TCS

[Polaraligned]

Well, kudos to whatever electrolytics RCA used. Personally, I just want my sets to run reliably, so I just replace the electrolytics seeing as though they may not be whatever brand/spec that RCA used. Not all electrolytics are this marvelous.

It seems like during the course of this you have had a number of resistors fail. Maybe I should be replacing all the resistors for reliability, LOL.

[Penthode]

Curious I found RCA electrolytics have been vey reliable. I had a 1949 9TC275 set with a slew of bad electrolytics it was stored in a wet basement in Chicago which may account for it. I have four other late '40's RCAs and all have original electrolytics. As I pointed out, the slow reforming did the trick: limiting the maximum current during reforming to no more than 10mA. And never applying power to the set until it has first been thoroughly vetted. Variacs and direct power application after sitting dormant for 50 years is a sure killer.

As for overall reliability over the last 6 months, the little 721TS has only had the one resistor failure in service. It just suddenly opened up.