Vintage capacitors replacement

[timbrown1961]

I have a capacitor that has 150wv,  4 wire,  black common, red 80 mfd, yellow 40 mfd, blue 20 mfd.  I can't seem to find the one to these spec's. What is the best one to replace it with?

[Gyro]

Your best bet is to replace it with a composite of three modern individual electrolytic capacitors. A 22uF, a 47uF (or 39uF but less common), and a 100uF (or 82uF but again, much less common), rated at 160V or 200V. You should find that the resulting package is significantly smaller than the original, but some ingenuity, plastic tube etc. Should produce something mechanically robust.

Edit: You won't find a single package part like that these days unless it is of similar age and condition. Apparently not the case.

[Zenith]

Those multipart electrolytic capacitors were popular in the days of valve (electron tube) equipment. They're not mainstream now, although a few may be produced for high end vintage audio amplifiers. There may be NOS somewhere, but I doubt it.

Your best bet is three modern electrolytics, 100µF, 47µF and 22µF and at least 150WV, and put them in a suitable case. Usually with a replacement, you can increase the capacitance with no problems, but don't go wild with that, and you can increase the WV, but don't go wild with that either. Look at the circuit before making a replacement.


Since modern electrolytics with etched foil tend to be much smaller than ones from years ago, you may be able to put them in the original case, if you want to preserve appearances. You'd have to bear in mind the ripple current capability. Those bulky old electrolytics often had high ripple current ratings.

[Uunoctium]

Depends on, what is your desire. If it's restoring an vintage instrument to his origingal shape & you're living in Europe:
FJZ "Frag Jan Zuerst" [ https://www.die-wuestens.de ].
He has tons of specialitys esp multi- elyt capacitors up to 550V in single can. And is one of the latest F&T [Fischer und Tausche] distributor, cause all others dropped selling F&T due too low sold quantities.
Is it only to got an instrument back to live, personally i have no qualms, lashing the new capacitors at an suitable place in chassis with cable ties and wire them on the fly to the old posts. Done that with fully success in my 475. And i have no respect, drilling new 1.2mm holes just thru the pcb of an HP5316B to make a bunch of EPCOS resp Siemens LL axial elcos fit. The old Sprague towers were rotten and down at 79nF - rated 3700µF - and 7000µF instead of 17000.

[GLouie]

You can get some multisection caps in new reproductions, but I don't see that exact combination so a modern kludge is probably the most practical. It depends on whether you want to retain the vintage look or not.

Modern multistage firecracker caps:
https://www.cedist.com/products/capacitors?filters=112a746c746a1143

Modern multistage can caps:
https://www.cedist.com/products/capacitors?filters=746a130c112a746

[Zero999]

Are you sure it needs replacing? Have you done any tests: capacitance and ESR? If it hasn't been used for a long time, it might need reforming.

[Benta]

More pertinent, is it really polarized? It could also be a paper cap combo.

[Gyro]

Are you sure it needs replacing? Have you done any tests: capacitance and ESR? If it hasn't been used for a long time, it might need reforming.

I'm definitely no advocate of premature electrolytic replacement, but a capacitor made by the Cosmic Condenser Co, with a waxed cardboard outer cover still being serviceable is maybe a tad optimistic. I suppose the less stressed lower value sections might stand a chance though, presumably it shares the same electrolyte volume for all three sections.

More pertinent, is it really polarized? It could also be a paper cap combo.

Given the capacitance values (unless it's far more massive than it looks against the edge of the keyboard) and the Black common negative label, it's a certain bet that it's electrolytic.

[Benta]

Are you sure it needs replacing? Have you done any tests: capacitance and ESR? If it hasn't been used for a long time, it might need reforming.

I'm definitely no advocate of premature electrolytic replacement, but a capacitor made by the Cosmic Condenser Co, with a waxed cardboard outer cover still being serviceable is maybe a tad optimistic. I suppose the less stressed lower value sections might stand a chance though, presumably it shares the same electrolyte volume for all three sections.

More pertinent, is it really polarized? It could also be a paper cap combo.

Given the capacitance values (unless it's far more massive than it looks against the edge of the keyboard) and the Black common negative label, it's a certain bet that it's electrolytic.

I'm inclined to agree, but as we're only allowed to see one end of the cap, who knows?

[MarkT]

More pertinent, is it really polarized? It could also be a paper cap combo.

Huh?  80uF cap that's not electrolytic?  That would be massive.   And the cap says "common negative" on the side, bit of a give-away that.

No need to test these ancient things, they look like they leaked a long time ago, they will be dangerous to the rest of the circuitry, so replace with extreme prejudice before powering anything up....

[temperance]

This forum needs a section on "recapping vintage equipment" and a method to ignore a forum section such that the recappers can recap the caps out of it while discussing the bass, the trebles, the highs and other capacitor voodoo related matters without some of us having to witness the equipment slaughtering going on at such unsupervised pokin around events.

[Zenith]

Are you sure it needs replacing? Have you done any tests: capacitance and ESR? If it hasn't been used for a long time, it might need reforming.

Ahh, capacitor reforming. Been there, done it. It's very popular amongst vintage radio and TV enthusiasts. Some unlikely candidates, such as double section electrolytics from a 1950s TV, reform quickly with very low leakage and the correct capacitance and ESR, others you'd imagine were more promising - more conservatively rated and operated at lower temperatures - are definite duds.

It's a possibility. but in this case I'd be inclined to replace the lot with modern caps, possibly putting them in the old case. There and again, we have no idea what the equipment is; a superb example of an early TV, or a piece of test equipment, where the appearance of originality counts for nothing and it just has to work.