[OldRestorer]

OK, I got my caps today! Going to get the answer to that question and go from there.

Kirk

[OldRestorer]

Well,
This sucks!
I was going through the Halson wiring and got the 40 and the 20 ready to replace the first large cap.
I was attaching the 40 to the neg and the pin 3-4 as we talked about and the neg lead on the 20 just broke off so it is no good. I took the last 20 I had and went to hook that up and the lead again from the neg just broke off. What crap are these Canadians selling? Now I have to wait and get a list of caps that will be over $20 just to get these 2 caps...
The 40 is hooked up and I know that the 20 goes from negative to pin 3 of the 43 tube but I just cant do it now.

The second cap is now what I am trying to figure out.
The negative runs to ground. The 1st positive runs to pin 4-5 of the 6C6 tube.
The 2nd pos wire runs to pin 5 of the 43 tube.

What I don't know is the values of the 2 replacement Ecaps, their voltages and if they are different values, which goes where.

[morzh]

Kirk, you unhappy panda you with your bear paws, what did you do to the cap? How did you break off pins from TWO caps? Go back pickin' cotton!
Oh, and bomb Canada! Just let Arran know in advance.

(let me guess, you bough axial caps.....)

Now.....let's see.

The first cap runs between GND and pins 4-5 ( I take it they are connected).
Pin 5 is Cathode and if there is a cap to GND it is the feedback cap, so it can be 5uF to 20uF and the voltage there is low so you do not have to exceed 100V rating (even 50 will do but I go 100V just not to keep many caps in stock).

Pin 5 of 43 is also the Cathode so the same goes here - the value can be the same and the voltage also.

[skyscraper]

FYI Kirk, if you want to go ahead and get just a couple, WJOE is cheaper, has no minimum order, and has faster shipping from the US.

[OldRestorer]

These paws make me fumble the caps i guess,

I did nothing, I looped them and hooked them in and the lead just broke off at the base. It has to be the caps since it was 2 in a row.
I will get the 2 20uF at 100v and thanks for the help... Once again...

sky,
I would love to order from someone other than JustRadios.com but they are the only ones I have found that carry the 1000v and 1600v caps.
What is the website for Wjoe?

[skyscraper]

Why do you need 1,600v caps?

www.wjoe.com

He has some high voltage TV caps.

[morzh]

Yes, Kirk, why?
Or are you talking of some other caps now?

[OldRestorer]

On My Westinghouse there are many 1000v and 1200v caps. I am actually short (2) .005 1000v caps. The Philco 45 has all 450v Ecaps also but I have not even gotten to that one yet,
I have the Westinghouse needing 2 caps, the Halson needing 3 caps, The philco 37-640 needing about 8 caps, The GD-60 needing 1 cap and I'm waiting for grill cloth for all 5 cabinets. I need to start slowing down to one radio at a time.
I ordered all the caps for the 5 chassis at one time so I don't understand why I am missing so many, yet I have 8 extra Ecaps and 25 extra caps I didnt use. I got lost somewhere...

I saw Joe's website and when I finish my list today I will see if I can get everything from there.

Why did I type all this random unrequested info? I dont know!

[skyscraper]

What sort of Westinghouse is this? In my, of course, limited experience, I've never seen a B+ higher than 400 volts outside of television.

[Mondial]

Most times the high voltage caps are across the primary of the output transformer where they can see inductive transients. When you have a push pull transformer the audio peak voltages can be twice the B+ supply.

If the output tubes are overdriven into cutoff, the inductive spike can reach very high voltages. This is one of the purposes of the cap as it forms a RLC circuit which effectively damps the resulting transient.

[OldRestorer]

it is a westinghouse wr12x16. Lots of 700 and 1200v caps.
Unless I am reading them wrong. that would suuuuuuuuuuck.
There is no parts list so I have to read the values off of the faded, dirty unreadable caps. It would say .100 700 513 on the cap so I assume it was a .1 at 700v

Oh I hope I was not reading these wrong. I already replaced every cap except the 2 .005 1000v I have to buy.

[skyscraper]

Someone correct me if I'm wrong, but as an AC/DC set, I don't think any voltage is over 160v. No harm in overkill, but there isn't anywhere near 1kv in that radio.

[Mondial]

Most likely not in a AA5, but theoretically the voltage across the output transformer primary with no load can reach infinity.

Say the speaker becomes disconnected and the output tube is driven into cutoff so whatever DC current suddenly stops. The magnetic field in the core collapses and tries to maintain the current flow. The energy stored in the magnetic field still has to be dissipated somewhere. The voltage across the winding can reach thousands of volts in this situation.

Here is an example of what I am describing. The trace shows the positive voltage across a 12 VDC relay coil. About halfway across the trace the relay current is suddenly shut off. Even though initially there is only 12 V across the coil, suddenly there appears a negative spike of several hundred volts. The same thing can happen across a radio output transformer winding

[Image: http://www.yoctopuce.com/pubarchive/2013...iode_2.png]

[BrendaAnnD]

I found this out the hard way when I was a kid.. playing with a 9V battery, speaker and OPT. I kept my fingers on both wires as I touched them to the battery (to make the speaker pop). When I let off the battery, the collapsing field knocked me on my arse.

[morzh]

I alsoo found as a kid, not as hard - I simply was buzzing a transformer's primary with a tester and when disconnecting I felt a bit of a ...not really a shock but it was certainlt electric and it was certainly higher voltage than that that does not produce unpleasant sensations.
Then I read up on it and since I only use one hand when buzzing large coils.

The flashovers in tube amps when musicians plug speakers hot.
Certainly if the speaker is soldered in, there is nothing to worry about and caps could be sized for the B+ only.
In an unlikely event of the speaker disconnect....one time probably nothing bad will occur.

But with pluggable speaker and people not nowing better....yes, there could be that Tesla coil effect.