Adrian I had the same thing in the same unit. I guess the electrolytic's were bad in allowing hum through. The tants go Bang and burn. Though all caps can go bang I suspect. Paul WB8TSL
On Sun, Feb 24, 2019 at 5:04 PM Adrian Godwin <[email protected]> wrote: > 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. > _______________________________________________ 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.
