Deco-Tel Candlestick Will Not Ring

[mblythe]

Hi, I have a Deco-Tel candlestick telephone which is fully functional except the ringer. I have read some other threads on this issue, but my candlestick has different wiring than the ones solved here so far. I was able to find a wiring diagram which I believe matches mine. I have attached it here.

In particular, the red ringer wire goes to terminal 10 as does the red line wire. The Green ringer wire goes to terminal 16 which meets one end of the capacitor. The green line wire goes to terminal 8 which meets the other end of the capacitor. I've tried some semi-educated guesses at moving wires around, but have had no luck.

Any idea on what needs to change? Is it simply a wiring change, or does this mean there is a faulty part?

Thanks!

[unbeldi]

Welcome to the Forum!

The way you are describing the wiring of the ringer sounds correct.  It is a simple ringing bridge with the ringer and the capacitor in series connected across the line.

It this a land line you are connected to or a VoIP terminal adapter?   VoIP ATAs often have a bit lower ringing voltage which could perhaps make a difference.

Perhaps you have a bad capacitor, or a bad ringer.   The ringer can be tested easily, with a piece of metal place a brief short across terminals 8 and 16 for  a fraction of a second.  This impulse should probably be enough to make the ringer strike once.

The capacitor can have two failure modes, either a short or a completely open fault.  Since the phone works I suspect it is not shorted, because this would place the line into a permanent off-hook condition, as it lets DC flow.

If you hear bell tap when shorting the two points, it could indeed mean the capacitor is open.  It is easy to replace these, it is a standard size you can buy for a quarter or less in quantity.   A single one may cost a dollar at Radio Shack.
The value is 0.47 µF  250 V (or higher voltage).

[mblythe]

Thanks for the reply. I am using it with a VOIP adapter -- the ObiTalk 100. I have already tried raising the RingVoltage to the highest setting, which has helped on other phones in the past. No dice on this one. I have another Deco-Tel candlestick phone which works fine, ringer and all, though its innards are different than this one. I'm guessing the problematic one is older, since it has a hardwired line.

I will try your jumping tip and see what happens.

Thanks again!

[mblythe]

Hmm, if I jump it, I get a small spark when I touch the terminal with the wire, but no movement on the ringer. I suppose this means the ringer is dead?

[unbeldi]

Hmm, if I jump it, I get a small spark when I touch the terminal with the wire, but no movement on the ringer. I suppose this means the ringer is dead?

Ok, the spark means the capacitor is not shorted, clearly, and it also means that the ringer coil is not broken, has continuity.
The capacitor could still be open.
I am surprised you didn't get a bell tap. Perhaps the bias is tight. I would try it again with the line polarity reversed, or the ringer leads swapped, but I think we know that it doesn't have a broken wire.
Since you already set the ring voltage high, it is probably not the cause, and these phones are not that ancient that at least 60 VAC won't ring them.

If you don't have a capacitor to swap in for a test, you could use a couple wires to strap the set to use the capacitor in another phone after the removing the existing connections.   You could even use the A and K terminals on the 425B network of a 500-type set for this test.

[mblythe]

I tried swapping the line polarity, assuming you mean swapping where the red/green wires are attached. No affect on the ringer. I guess the only thing left is try a new/different capacitor?

[unbeldi]

yes, I meant the line polarity.  On single coil ringers this test probably does work the same as on the old ringers, so I am not surprised.

Since you haven't mentioned what kind of measurement tools you might have, it seems swapping parts is the way to go. What type of resources do you have?
Do you have a 500 type telephone set? On these it is easy to borrow the ringing capacitor for a moment, since the screws are easily accessible.  You could simply disconnect the ringer in a 500-set and wire your candlestick ringer in place for testing.

[AE_Collector]

These Deco Tel phones were made with different brands of components inside to satisfy the local Telephone Company as they were originally rental sets owned by the Telco. The network in yours is AE (line to 8 & 10, capacitor/ringer bunching point 16 etc) so the ringer is likely AE as well and I would assume it is a single gong ringer fitting in the base of a candlestick phone. These ringers can be very temperamental.

Try putting your finger on the armature of the ringer while the line us ringing and see if you can detect any attempt of the armature to move.

There should be a bias spring to play with, it is a thin straight (stainless steel?) wire that engages into a little hook on the armature. I have also had to use needle nose pliers to slightly adjust the 90 degree bend in the armature to get something happening. I once found one of these ringers that the magnet had disappeared out of rendering it useless.

As mentioned it could also be related to your VOIP adapter, any opportunity to try the phone on another phone line somewhere?

Terry

[stub]

Terry,
         That's a  46 or 46a ringer and they are as you say " very temperamental " even on the POTS line. Here's pic of 46a . Hope this helps.    stub

                 left click on pic to enlarge

[mblythe]

Here is the model info on the bottom of this phone. Not sure if I had the right wiring diagram in my original post or not. The first digit is impossible to read on the first line.

stub that ringer schematic looks like a match for this one.

I have had a 500 type phone in the past, but I don't believe I do currently. I will double check.

[stub]

 mblythe ,
              I've had several of those capacitors go bad . If you can't find one PM me.   stub