Values stamped on the can are 20-350, (three times, semi-circle, square, and triangle). Below these three values is 20-25 DC

That would indicate that it contains three 20 MFD, 350 WVDC capacitors, and one 20 MFD, 25 WVDC capacitor.

When you order, it is OK to use the currently available 22 MFD caps, if no 20's are in stock where you buy from. Additionally, it is OK to get 450 WVDC caps for the first three. You can go over with the voltage capability, but never under, for any of the caps.

Many of us simply disconnect the wiring underneath the chassis that goes to each of the multi-capacitor's solder lugs, and connect the new replacements to them on the + side, with the negative lead going to circuit ground, which is usually an outer tab on the original capacitor.

Alternatively, you could remove the original, take out the old caps, re-stuff it with your new ones, and remount it.

Is this the easiest method?, or used only if there is no correct can available?

Yes, wiring the discrete replacements under the chassis is the easiest method. Just leave the existing can in place for cosmetics, with it's wiring re-routed to the new caps.

I am afraid you'll look long and hard to find an identical replacement for the existing can, and "NOS" capacitors can't be trusted; you want brand new stock, which is cheap and readily available on-line.

Here's the place I use...You can get four 22uf/450 volt Electrolytics for six bucks, plus shipping;
http://www.thetubecenter.com/Electrolyt ... rlist.html

This way it's a complete no-brainer, since all the capacitor and voltage values are the same, and you won't accidentally wire a lower working voltage value in the wrong place.


**Staff, you might want to move this thread to the EMR forum, since it's becoming a how-to.

Thanks, I'll get those ordered. To save on shipping, what other type of caps do you think I'll need to get?

Tony, you should take an inventory of all the wax caps you have under the receiver. They are cheap and should replace all eventually.
Jerry

Will do, Jerry

Took a couple pics of the caps.
I'm not sure if I'm reading the stripes/dots correctly though.


First pic
If I'm reading the two large black ones correctly, they are .047 mfd 400v. (yellow,violet, orange, gray, then a final yellow stripe).
The brown one in lower right side is a resistor correct?

Second pic.
There are three black flat caps with dots, (red-red-orange is .022mfd?), (orange-green-red = .0035mfd?), (orange-white-brown = .00039mfd?). All three have an extra white dot at one end which would be 900 volts? Seems high. Should I replace them?
There's two white paper caps with the info printed on the side, so no questions about those two.

Regarding the first pic, AFA capacitance value of the "Bumble Bee's", you are correct. The replacements you buy will prolly be rated at 630 volts. Your assumption is also correct regarding the brown 22K resistor.

Regarding the second pic, with the three black rectangular Mica caps, we normally leave those alone. They are not 100% guaranteed to last 70+ years, but their failure rate is quite minimal.

Thanks Fifties.

Looks like all I need to replace is the four Electrolytics in the can, the two bumblebees, and the two white paper caps, then power the radio up to see if it works?

If any Moderators read this, please move this to EMR forum

Carry on.

Ok, I have recapped the radio. Now when I power up I get some static and a little popping from the speaker. Kinda like the sound an old vinyl LP makes in the run-off area. The volume of the static does not change wither the volume knob is down or all the way up.

So whats my next step? Tubes? I noticed that two of the six tubes light up, the other four do not.

Given that tube heaters are normally wired in series, either they all light, or none of 'em do.

Time to learn. Google the basing diagram for each of the four that light up, so you can determine what pins the two filaments are located at, then remove them, one at a time, and use your meter to check continuity. You should get a few ohms resistance. If the meter stays at infinity, it's obviously open.

50s is correct in his statement that tubes wired in series will all work or none will work if you have an open filament on one they all go out. Think the old christmas tree strings. However your radio has tubes wired in parallel. One or more can go out and others remain glowing. Just a point of clarification. Follow his guidelines and remove the tubes one at a time and check resistance from pin to pin for the filaments. Some don't "glow" as bright as others. Wouldn't hurt to run it for 5 minutes or so and feel the tubes you don't feel are lighting up to see if they are getting hot.
Jerry

+1

Thanks for the tips guys.
Upon closer inspection, the four that I thought were not working, have a dim light at the base, as opposed to the other two that are bright all the way up to the tip. I checked all the filaments with a meter, they appear to be ok

One other point of concern is that since I have no schematic, I don't know the order in which the tubes are arranged. Will it damage the radio if the wrong tube is in the wrong place? Is there a way to determine the order without a schematic?

The set has a power transformer..chances are there is a bad tube somewhere. That would have been the first check after the Filters were repaced. The other caps were probably OK as they are disks and bumble bee's.

Dale

Is there any markings on the sockets themselves?, otherwise, you have to do it by the wiring and position in the set.

No markings on the sockets. I know where two of the six tubes go, because of the size difference. The other four are all the same size, 6BA6 (two of these), 6AT6, and 12AU6 (appears to be a replacement, not a zenith brand).

Here's a post in the thread you quoted in your OP;


That 12 volt tube definitely doesn't belong, so your first order of business now is to get the proper tubes.
I use this outfit;
http://www.thetubecenter.com/vacuumtube ... 1-1z2.html

Or you could post a WTB in the classified forum.

AFA where they go, search to determine their functions (Converter, IF Amp, Detector, Audio Output, etc), and we should be able to assist, if necessary. You might actually learn something, lol!

Just kiddin'!