How to Wire 51-501-T with 425A Network, and C3A ringer, & 426A Tube.

[Wallphone]

The "E" screw on a 425A network is just a terminal, it does not connect to anything inside the network.
Take the three wires that connect to the E terminal (according to Dan's diagram) and connect them to each other and tape them. See if that works.

[Phonesrfun]

Mr. A:

Here is how to wire it.  Bear in mind that the tube is polarity sensitive, so if it does not work this way, reverse the red and green line wires as described below.

To start with, connect the red line wire to L2 of the network, and the green line wire to L1 of the network.  If the line cord has a yellow line wire, then connect it to G, but it will not be used for anything else, and G is just a blank terminal inside the phone. (This is standard line cord wiring)

Connect the black ringer wire from the C3 ringer to terminal L1 on the network.
Connect the red ringer wire from the C3 ringer to terminal A on the network.  (We are using A as a tie point)
Connect both the red and black wires from the 426A tube also to terminal A on the network.
Connect the yellow wire from the 426A tube to terminal L2 on the network.

Try it out.  If it doesn't work at all, reverse the red and green line cord wires;  connect red to L1 on the network, and green to L2 on the network.

If that does not work, you may have a bad tube.

[mr_a500]

Thanks Bill for those clear, detailed instructions (looks same as Dan's diagram, but polarity reversed). I wired it exactly as described, but it didn't ring. I then reversed the polarity and it still didn't ring (not surprising, because I already tried Dan's diagram). So it's possible I have a bad tube.

I then wired it without the tube again and once again got that weird problem - I hang up and 18 seconds later I get a single light "ding dong" and when I answer, it's the automated "hang up" message. If I don't answer, the line goes dead a few seconds after that.

It's very, very weird.

[Phonesrfun]

Try this, then.  Red ringer wire to L2, black ringer wire to A.  A jumper wire between K and L1.  No tube.  That would be a standard ringer wiring for a bridged ringer.  That should work regardless.

By the way, a question:  Are you using a regular phone line coming from a central office, or an internet phone, FIOS, or something else?  If you have one of those latter types of phone service that comes from a router or ATA, that could be the source of the problem. 

The tube is polarity sensitive and uses the voltage of the phone line and the superimposed ringing current to do its thing.  They are designed for 48 volts, which is the voltage a regular old phone line uses coming from a central office.  Routers and ATAs tend to be based on 28 volts, which greatly reduces the effectiveness of one of those tubes.  I have such a tube and I have Vonage,so my tube does not work very well.  Jorge Amely is running his pbx through a Panasonic 616 which is a 24-volt box, and he seems to have no problem.  Results do vary at less than 48 volts.

[mr_a500]

Yes! That did it. Thanks! It rings very weakly, though.

I'm using a VOIP line. I don't know about the voltage, but I had no problem with 4 rotary phones connected, all ringing.

[Phonesrfun]

Normal ringers without the tube are not influenced by the line voltage, since the only thing that makes a normal ringer work is the AC ringing current, which the Voip boxes have kept in place.

I am surprised that it rings weakly.  A C3 ringer should ring just as vigorously as a C4.  You might check the bias spring.

[Dennis Markham]

Try moving the bias tension spring and see if that improves the ringing.  That is the little thin wire that is below the gongs and rides in a small copper guide.