Electrolytics

Electrolytics caps: standard cctech recurring topic #2 I swear this concern about electrolytic cap failure is a legacy myth that has filtered down through the antique radio community, going back to issues of wet electrolytics and *early* dry ones. For pre-1950's tube equipment and later *consumer-grade* *tube* equipment I may replace electrolytic (and paper) caps as a matter of course. Just about everything else is left as is. My (industrial-grade) tube frequency counters from the late-1950s are functioning fine with the original electrolytic caps in them. In one of these counters there was a bad oil-filled bathtub cap (one of the most reliable types of that era). The electrolytics were fine. Pretty much all (I can't think of any exceptions offhand) of my dozens of transistor and IC counters, calculators (and computers) from the 60's and 70's are functioning with the original electrolytic caps in them. Occasionally, I will bother to use a variac. I have had one 'lytic cap explode on me. That was in a home-made tube radio power supply from the 1950's that I received in the 90's. Made quite a mess. The mushy innards of the capacitor were splattered around the entire underside of the chassis. That situation would have been worthy of initial replacement or a variac, but I didn't have one at the time. The issue of poor-quality 'lytic caps from the late-1990's/early-2000's is well known in the industry, but that was a quality issue related to several particular manufacturers (example article: http://crppit.epfl.ch/documentation/Computer/Hardware/Problem/Defect%20Main…). Aside from such particular issues as this, IMHO, concern over modern electrolytic caps is vastly overrated.