[Penthode]

Before condemning the electrolytics, I make the effort of at least first trying to reform the dielectric and thoroughly testing old electrolytics especially leakage. I have found before powering up and restoration, the electrolytic capacitors, having remained dormant for decades, will be leaky and the capacity risen. I attributed the rise in capacity to the diminished or thinning dielectric. Certainly after the capacitor dielectric has been reformed, the capacitor will measure more closely to their rated capacitance printed on the can.

I am surprised the high percentage of 60 and 70 year old capacitors which have survived. My RCA 1947 721TS l made a point of very slowly reforming each of the electrolytics over the course of a week or so. I feel because the set had not been powered on for decades and the set had for over 50 years stored in a heated attic, all of the chassis mount electrolytics survived.

I restored the set in 2020 and five years later I regularly power it on and the capacitors remain fine. It is nearing it's 80th birthday!