Pilot 240 Question

[archie2]

My Pilot 240 is off the dim bulb "variac"and sounding great. I'm planning to replace the coupling caps with orange drops but I don't know how to read the power supply caps. The cans have multiple MFD values stamped on them....80/40MFD on one and 20/20/40MFD on the other. I did a search and it seems these are ranges????? If I were to replace these how would I know what to order?

 

[Redboy]

Archie, the cans have multiple electrolytic capacitors in them. If you look underneath you'll see that they have two or more terminals on them, usually one for the shared ground and another for each value in the can. On the can itself there should be shapes (triangle, square, half-moon, etc) next to the individual values. There are corresponding shapes by the terminals underneath so you know which terminal is which.

Antique Electronics Supply (www.tubesandmore) has a good selection of replacement cans (link). They're spendy but they're what you need.

Another possibility is to put separate electrolytic capacitors under the chassis if you have the space (replace the can's 3 values with 3 separate caps).

Have you got a schematic for your 240?

 

[archie2]

Thanks Nate, I read the multiple caps in the can in my research but when I looked at the cans in Antique Electronic Supply they seem to have a single value. I didn't use your link yet.
The terminal symbols are on the cans, I didn't know about that, extremely helpful.
Yes I have the schematic.

 

[archie2]

Now I checked out Nate's link and they fit the bill. Pricey buggers though, as you said. So now I have choices, leave the present PS caps in, replace with matching cans or mount separates underneath. I'll see what kind of room I have underneath. Thanks.

 

[Redboy]

So now I have choices, leave the present PS caps in, replace with matching cans or mount separates underneath.

In my mind, you've got two options - the present caps are 50 years old and may be a very real fire hazard. Braver folks than I will tell you they're okay, though. You'll have to make that call.

 

[specialidiot]

Another option is to stuff the old cans with new separate electrolytics. I've seen some threads on that here, so try the google search option.

That said, as long as there is room underneath, I'd go with mounting the separates as Nate described.

Going with the originals is asking for trouble, IMO.

 

[archie2]

I'm convinced, two options. 50 year old caps can be/are hazardous. This will be a first for me.