Restoration Commences on 1947 RCA Victor 721TCS

[JohnCT]

Originally Posted by Penthode

If the electrolytics lasts 100 hours and I do not abuse it I expect it will last the remainder of my lifetime. Would you agree?

I have no way of knowing how long the caps might last or how often you will run it. It may go 100 hours, it may go 20, or it may go boom the next time you try it...

Anything I restore I do so with the expectation that the next guy won't have a lot to do if something inevitably fails - and that guy will be one of my two sons in most cases.

I have two items of significant age running original capacitors: one of my Fisher X-1000 integrated tube amps from 1962 has all it's original capacitors - my original X-1000 blew a can about 35 years ago. In any case, I don't let either Fisher run unless I'm in the same room with it.

The second is my 1929 RCA Radiola 62. This has no electrolytics at all and the paper capacitors are made with rice paper instead of rag. Radiola experts say don't change any caps in a 20s Radiola unless you run across one.

I would also venture it will outlast a modern replacement if I was to install one.

No chance. Go to DigiKey and order Panasonic low ESR, high pulse caps. These will outlive you and I combined.

The 721TS has been running 20 hours now and still running fine...

I used to do monitor work for an arcade operator many years ago, and he would say that you're on bonus time...

Parting shot: when I restuffed the four cans on my TV, I did a postmortem on the innards and what I found is a lot of degradation in the foil and the paper as I unrolled it. It wasn't a matter of if it was a matter of when. The other five cans in my TV are still original and of the same manufacture, but I know what's inside and I know they need to be serviced before they burn out a part that could only be sourced from the nation of Unobtanium.

John