Just to sneak that back on-topic .. the most recent tant failure I had was in a KS-24361. It was after the dc-dc converter so it didn't look like a short to the input - it just increased the current draw. Running off a cheap laptop supply, which overheated and melted instead of shutting down or blowing a fuse. It took out the breaker for the whole ring main.
Replacing the tant was the only action necessary for the KS-24361 itself. No other internal damage. On Sun, Feb 24, 2019 at 2:02 PM Adrian Godwin <[email protected]> wrote: > I think I've had as many shorted-out tants as dried-out electrolytics. > It's just that they appear in 80s gear instead of 60s. Then there was the > flood of high-esr electrolytics from when - early 2000s ? > > > On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) < > [email protected]> wrote: > >> Several people have asked about the Len Cutler ban on Aluminum >> Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist could >> shed more light on this too. The legend of the ban was passed along to >> me, perhaps by Lou Mueller, who liked to tell stories of the old days. In >> 1985, we were not taking the ban literally. For example, the 2400uF main >> power supply filter capacitor was AL-Electrolytic, as were a few other >> smaller capacitors on the power regulator. I sidestepped the capacitor >> issues on my simple battery charger by not having a filter cap after the >> transformer/full-wave-bridge, and just used 120 Hz pulses, since the >> battery didn't care about DC vs. pulsed DC. (I thought it was pretty >> clever to leave out the main filter cap.) Where possible, Tantalum >> capacitors were used. For the few places where AL caps were used, they >> were heavily de-rated, operating at 50% of rated voltage for example. >> >> As one reader pointed out, back in the 1965 when the 5060A was developed, >> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I >> worked on the 5061B. >> >> >> From: time-nuts <[email protected]> On Behalf Of Rice, >> Hugh (IPH Writing Systems) >> Sent: Saturday, February 23, 2019 8:49 PM >> To: [email protected] >> Subject: [time-nuts] HP Stories: An architectural view of the HP >> 5060/5061 and awkward oscillator adjustments. >> >> Hello Time-Nuts, >> >> .... Stuff deleted ..... >> >> >> It was fantastically reliable. Only linear power circuits, with robust >> heat sinking of all power devices. The legendary Len Cutler ban on aluminum >> electrolytic capacitors. 5060s were still in use in 1985, after 20 years of >> constant operation. Likewise, 5061As were abundant in time standards for >> 25+ years until they were replaced by the 5071A in the 1990s. >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
