The Unthinkable has Happened!

[AD7VB]

It seems I have nearly depleted my seemingly bottomless pit of high voltage vintage capacitors. If anyone has any 450V multisection electrolytics they want to get rid of, I can use a few for some upcoming restorations. I can also use newfangled high voltage caps too....I'm not really into the capacitor "re-stuffing" bit.

Eric

How about www.tubesandmore.com/search/node/multisection or www.hayseedhamfest.com/capacitors/Capacitors.html for new ones.

73 Todd
AD7VB

[KJ4YEV]

CE Distribution has stock. Supposedly, they bought the tooling from Mallory to make them. As far as I know, they are the only source for them now. The quads are pricey ($33.00), but when they are being used for tie points for multiple components, exact replacements are easier to install than four individual units. Theirs are now rated at 525VDC.

Al KJ4YEV

[KM1H]

I dont like dealing with any outfit that wants my personal information just to look at their audiophool crap.
Tom at Hayseed Hamfest has whatever you need for a vintage can cap or can have it made up at a reasonable price.

Carl

[WD0GOF]

Under the chassis is the way to go. You may want to look at a more modern replacement for the alum. electrolytics. The Polypropolene (PP) capacitors are self healing, with ESR's that are less than 0.009 ohms, and available up to 1300v. Most power supplies use series electrolytics with parallel resistors for bleeders and equalization. The polypropolene's simplify the upgrading of power supplies and are more reliable than alum. electrolytic. I have used them in Hallicrafters, PS-150's, PS-500's, SR-150's, 160's and 500"s. In the Hallicrafters power supplies the ripple in the stock power supply normally just will meet the original factory spec's, with the ripple on the HV around 2 to 5% over spec limits. With the polypropolene replacements the ripple is consistantly 1/2 the spec limits.

Go to http://www.mouser.com/Search/Refine.aspx?N=16660333 and select 'polypropylene (PP)' to see what is available.

73, Walt.

[W2WDX]

First of all, CE Distribution is not retail and only sell wholesale, which is why you cannot see pricing. Their retail website is Antique Electronic Supply at http://www.tubesandmore.com/.

Secondly, you all better start getting used to going to "audiophool" web sites since they are the only ones keeping the electronic parts business going, especially for vintage type parts. Like newly manufactured twist lock multi-section caps. If us cheap Hams were all there was we wouldn't drive the numbers of sales needed to keep products like this around. The problem I have with these caps is the cost. $28-$35 does seem "Phoolish".

And Walt, are you serious with the polypropylene caps. Don't you need polarized caps for filtering? I mean, explain it to me because this would be an easy solution if it works.

[WD0GOF]

First of all, CE Distribution is not retail and only sell wholesale, which is why you cannot see pricing. Their retail website is Antique Electronic Supply at http://www.tubesandmore.com/.

Secondly, you all better start getting used to going to "audiophool" web sites since they are the only ones keeping the electronic parts business going, especially for vintage type parts. Like newly manufactured twist lock multi-section caps. If us cheap Hams were all there was we wouldn't drive the numbers of sales needed to keep products like this around. The problem I have with these caps is the cost. $28-$35 does seem "Phoolish".

And Walt, are you serious with the polypropylene caps. Don't you need polarized caps for filtering? I mean, explain it to me because this would be an easy solution if it works.

Yes, I am serious about the Polypropylene (PP) caps. In days gone by electrolytics were the only thing available that would provide the high capacitance, low ESR and high ripple current needed for power supply filters. The chemistry and phisics of electrolytic construction made them polorized, it was not a circuit requirement. The Polypropylene (PP) film capacitor's diaelectric is a solid film and is not polorized. The poly cap's much better esr specs usually reduce ripple to roughly half what electrolytics deliver. The ESR of the cap to a large extent will determine the ripple in the DC output. The cheap electrolytics ESR ratings will range from 10 to 35 ohms where the poly's will run from 0.005 to 0.015 ohms. To get a 20uf electorlytic with esr that low you will spend $20+.

You have to shop a little to find them at an acceptable price. Even with frugle shopping the poly's will cost a little more than the cheap electrolytics and about the same or a little less than high quality low esr electrolytics. Example a 20uf/1000v cap can range from $22 to $8.30. The higher voltage ratings lets you eliminate series cap and resistor networks.

There is a lot of tech info on the www just search around.

73, Walt

[W2WDX]

I see of course, the Elect. Capacitor had to be placed in the correct polarization because of its nature, not because of the circuit. I see. Of course. Makes perfect sense. Sometimes the fundamentals escape me.

Now the one thing I have noticed in reading so far is that these polypropylene caps made for PSU designs are quite pricey, especially once you get into the high voltage ranges of 450V and higher. And they talk about special "discharge modules" due to a special discharge rate that needs to be applied to these caps.

Now in new designs, this is not really a problem. (I will be looking onto this more, with great interest for some products I am developing). However in an old radio especially receivers, the cost of the cap can be more than the cost of the entire radio in today's used market, say for a Hammarlund HQ-100.

So, if you can, give some examples of some values (capacity and voltage) and respective costs you have seen.

Thanks for the tip.

John LeVasseur, W2WDX

[WD0GOF]

The two I use the most are 10uf/1200v @ $8.96 and the 40uf/900v @ 11.55. The 10uf replaces three 30uf/450v that are in series. A 30uf @ 450 with an ESR less than 5 ohms can some times be found for around $4 usually around $6 or more. When you series the caps you have to split the bleeder resistor and paralles each cap. So in this application I eliminate 2 power resistors and 2 capacitors. The 40uf/900v cap replaces 2 80uf/450 caps in series.

If you go to http://www.mouser.com/Search/Refine.aspx?N=16660333 then check the "enable smart filter" box, then under 'dielectric' select "polypropylene (PP)". Then you can search around the voltages you want and the capacitance values.

Remember with the extreemly low ESR of the polypropylene caps you can usually go 10 to 15% lower on the capacitance value and end up with less ripple than the original ckt.

73 walt