Troubleshooting a Western Electric 554; no dial tone

[poplar1]

C4A ringer:

Black to Slate = 1000 ohms

Red to Slate-Red = 2650 ohms

Total black to red if slate and slate-red wires are joined together = 3650 ohms

[Key2871]

I'm surprised that Western didn't at least clean the ends properly before soldering. So that would explain a couple ringers I had trouble with..
At least using something to dissolve the coating would have been far better than nothing. Scrapping the wire could create a weak area in the wire.

Ken

[ehbowen]

     Regular Member Post

I made an error in the above paragraph. The whole intent was to check the connected coils for continuity and using 100 ohms was wrong. I've been told the resistance of both coils connected together when using resistance (ohms) for continuity is about 3600 ohms for a C4 ringer.

All of my phone stuff is in storage due to a house move so I didn't have one at hand to check it and didn't take the time to look it up. No excuse for not doing that. Thanks to the member who made me aware of this.

I think what I was thinking was that resistance from alligator clip leads themselves not making good contact with whatever it is clipped to can be 100 ohms or so, give or take.

I'm still in a bit of post "new guest" mode, a foggy daze.

Well, that definitely does make a difference. With the slate and slate/red wires connected and the multimeter set on high range resistance, I show ~400 ohms between the red and black wires at the terminal block.

Edit To Add: Just saw the posts above. I disconnected the red wire from the terminal block; looks like I was getting a sneak current path somewhere. With the red lead isolated I get 2800 ohms red to slate/red; 1000 ohms black to slate. Total resistance red to black 3900 ohms...but, as I said, with the red wire connected to the terminal block I only get about 400 ohms. Trying to see where the current is going....

Edit Again: Duh. When I did the testing I had the receiver off-hook. With the hook switch depressed the resistance goes back to where it should be...3900 ohms red to black.

[RotarDad]

On the topic of wire coating, I did some research and and ran across an article from the Seymour Duncan custom shop regarding vintage electric guitar pickups.  Apparently they use wire that is enamel coated, as this was the spec in 50s-era coils used in Fender Strats and others.  The article states that the wire ends must be sanded prior to soldering.  With the high quality WE was committed to, it is surprising that they left only the cut end of the wire for the connection.  I've never found a bad ringer, so I'm guessing that their process must have been good enough to have a very low failure rate.  More attention to the wire ends apparently wasn't deemed necessary.

I've been working on my basic electronics knowledge.  It is just amazing how electron flow and magnetism have been harnessed to power our world.

[poplar1]

The gongs appear to be very close to the clapper. Did you try moving the lever on bottom of phone to "Loud" position, in order to increase the distance between the clapper and the moveable gong? If so, do you feel any movement of the clapper if you touch it during the ring cycle?

[ehbowen]

Well, I ordered a new wall plug and a new-to-me ringer from the Old Phone Shop. At first I still had no dial tone with the new plug, and I pulled out the multimeter. Even with the new plug, I still didn't have continuity with the jack wiring with the baseplate in place and plugged in. Apparently there was something about the shape of the inside of that wall jack which didn't mate properly with a wall telephone plug, but would work when I tested it with the standard line cord and with the 500. No problem, though; wall jack plates are cheap...$2.79 at Ace Hardware for a Monster surface-mount. With it in I did get continuity between the wiring and the phone leads, so I reinstalled the modular backing plate on the 554 and hung it on the wall. Good dial tone and, after I also replaced the ringer, I was able to call both in and out. So, thanks again for the help with troubleshooting; it'll be easier next time!

Edit To Add: Hope that it's ready now for another 55 years; date code inside the 554 was 5-64!