Subset problem

[jdwilker]

I'm a newbie on this forum and would appreciate any advice.  I have a WE 51AL hooked up to a 295A subset. Recently it stopped working and I noticed that when I connect it to the line, the ringer is energized (moves the ringer to one side) and the line acts as if the receiver is off the hook even though it isn't. Since this condition exists even if the phone is disconnected from the subset, it must be the subset. And since the only components in it are a ringer, a coil and a condenser, my guess is the the No. 21 D condenser has broken down.
Am I right and if so, where could I find a replacement?

[HowardPgh]

jdwilker-
Your diagnosis sounds good for this symptom.
You probably have to find a junker subset for the part.
I don't know what the value of the 21D condenser is. (1 mFd or 2 mFd).
You may be able to find some smaller value capacitors (.47mFd)  and wire them in parallel to reach the desired value. mFd= uFd
Exact value isn't critical as long as your close, the old ones vary a lot in value.
They are probably small enough in size to put in the 21D can.
Good luck in your repair.

[jdwilker]

Thanks so much for the reply Howard.  A couple of followup questions:
- I haven't taken the 21D can apart. Are they electrolytic or other composition?
- What voltage value do you think would be safe?

[dpaynter1066]

200v non electrolytic.

Newark electronics sells new made capacitors and will sell small quantities to individuals, also Jameco electronics.  Others may have minimum orders.  You can wrap the gaudy colored plastic capacitor in  dark grey construction paper etc and a spot of white glue to make it inconspicious.  leave the disconnected bad cap in place for show.

In old radios, we hollow out the shell of the bad capacitor and stuff the new one inside to hide it, recyling the original wires. If done carefully, its very difficult to tell it was ever messed with. but troublesome to do that.

For original parts try phonecoinc  or Old phoneworks  or the ebay.

if the ringer circuit is the bell  in series with the cap across the line and you disconnect one of the ringer coils to break the circuit and it starts working properly,  then capacitor is shorting  (leakage).

 The fact that it was working previously with no problems seems to indicate that everything was likely wired correctly.

[jdwilker]

Thanks for part info and the testing tip.  I'll give it a shot this weekend.

[dsk]

Thanks so much for the reply Howard.  A couple of followup questions:
- I haven't taken the 21D can apart. Are they electrolytic or other composition?
- What voltage value do you think would be safe?

The old cap was a paper cap, so what you need is a bipolar cap rated at at least 200V.
The it will probably work well with a 1µF cap, even if the original was 2µF. Slightly weaker signal in the receiver, and little reduced ring (Ren no)

dsk

[jdwilker]

Here's an update - old Betsy is back on-line.  I found an original WE condenser from the folks at Phonecoinc, installed it this weekend and she is working like a charm.  Thanks to all the folks who provided some very good information.

I guess I can't complain about the original condenser failing.  After all it worked for 100 years!  What device made today will still be running in a hundred years?