WE, or about any Common Batt phone

[trainman]

I thought you had actual cords on it. You do know that a telephone switchboard plug had 3 insulated sections? So, if using a stereo plug, i suppose the first section woukd be the Tip . The second section would be RIng, then the largest section of the plug would be Sleeve, to correspond to a switchboard plug.

[HarrySmith]

If all you are looking for is to have 2 phones talk to each other I think there is a much simpler wat to do that. You do not need the switchboard unit at all. Is that what you are trying to do?

[trainman]

Tip and Ring is the voice path. The cord sleeve is a third wire in the cord that is the battery or ground path, depending on what part of the circuit is activated, for the relays. 

Looking at the cord unit with the plastic terminal strip where the cord connect would be the front. So, right side would be right cord.  Left side, left cord.

Now, without a station line mocked up and wired correctly, the supervisory lights on the cord unit wont work exactly like they should. But if we ignore the station jack light, just going by the lights on cord unit.

Right side, with TR connected to the right phone and cord sleeve grounded, with phone on hook, right cord unit should be lit. Pick up phone, light goes out. S relay should be picked up. Disconnect sleeve ground and S relay is out.

I pretty much have the right side operation down. Its the left side i dont know without looking up

[trainman]

Another thing. If your RB relay has contacts, the GTE schematic isnt entirely accurate.  But it still good for what you are trying to do.

The Bell Labs version in SD 65520 shows the wire additions for the RB relay with contacts.

[RB]

ok, a little background. I know about the cords, and have them wired up correctly. they just don't happen to be oem equipment, wish they were!
i am quite comfortable readin schematics, have been doin it for a long, long...long-long time lol. I just don't have experience with phones...used them, messed with addin a second phone, but did not get into the insides of them...until now!
I built a switchboard for my phone collection. it is capable of connecting magneto phones now. and has the ability to switch from lb to cb.
this cord set will be modified to fit in the box,"it is quite a bit too small to hold this thing in its complete form. And, since i have 3 cb phones, I want them connected through the switchboard also. thats the reason for all this. I will get there, just takin longer due to the damage to this cord set before i got it.
I want the lites to indicate on hook/off hook for the cb phones, and maybe, at some point, for the mag phones also, will see how this goes.

Now, without a station line mocked up and wired correctly, the supervisory lights on the cord unit wont work exactly like they should. But if we ignore the station jack light, just going by the lights on cord unit.

Right side, with TR connected to the right phone and cord sleeve grounded, with phone on hook, right cord unit should be lit. Pick up phone, light goes out. S relay should be picked up. Disconnect sleeve ground and S relay is out.

I pretty much have the right side operation down. Its the left side i dont know without looking up

I think the S relay has control issues, it seems to work almost as you said, but using the left phone, not the right. the right phone does not effect the lights...yet! Left seems to work correctly.
I believe i need to fix the right phone activity so the lites work as they should. i am sure there is still a contact faulty, or more...
If the power is correct polarity, I should be able to solve the rest. learning curve and all.
I should have more function info by tomorrow. I only get a few hours a day to mess with it. and then, I gotta stop and go to work, and I forget parts of what I have done so far. ever had that happen? lol
Thanks again for your patience!

[trainman]

Does your unit have a lever in the front, under the ringing key push buttons? In normal operation, this should be pulled out, lever straight up. Turning lever to right would patch the operators handset into the call. Up woukd be normal. Pushing it inis for night connections or when the station would dial fpr itself, instead of the operator dialing the call. Pushed in, it would disconnect the S and T relay coils from the circuit.

[RB]

I am with you on all that. all switches in their normal upright locked position. cleaned and adjusted ring and through dial switch contacts last nite, no help, just cleaner. one thing I need to clear up, I have heard that this model, 555 switchboard could operate in a wide range of voltages...
I do not know how to tell one from another, since this is my first physical piece i have had my hands on.
anyway, not knowing what supply this particular cord set operated at, I erred on the side of safety, and am using a 24 volt DC power supply at about 1.8 amps. At first, all the relays would snap into position, but now that i have some lites working, some relays seem to have gotten sluggish.
have i made things worse usin an under powered supply? even if, that does not account for the short in the sup lites... I did a bunch of testing last nite, and most everything you suggested, I have tried. only the right sup lite works , and only if i pick up the left phone.
Now, assuming, rt and lt on the cord mount plate, stands for left cord, and right cord...or did i mis understand that?
one ting i do remember, while cleaning the nite switches, i noticed when the right cord nite switch opened, the two 1/2 brite sup bulbs would go out.
it still bugs me why the lites come on together, dimly. until i ground the sleeve?
I will have the j number tomorrow, forgot notes.

[trainman]

RT should be right cord, etc.

i think im going to  have to take a  cord unit out and mock it up. im telling how it should work installed in a complete swithboard. behaior might be different wired up the way you have it

[RB]

I found the J number in an old post...J59013 E4 L6 B
will this cord set run on 24 volts? or do I need 48 volts?

[trainman]

Im running mine on 24v and it works just fine. I just had to change the bulbs so they werent dim.

I dont know what the J number is for mine, but mine havent been modified. Mine match the GTE schematic. The Bell Labs drawing in SD 65520 actually show some of the modifiactions like the RB relay.

The J number on yours seems to match a 555. The other letters and nimbers are for modificatins.

I looke at mine and the terminals for the cords are Right cord connections across the top, and Left Cord connections are on the bottom.

[trainman]

A 557 also uses the a cord u it with the same J Number. 557 works similar but not exactly like a 555. I looked at a 557 schematic and the cord unit is almost ide ntical.

[poplar1]

A 557 also uses the a cord u it with the same J Number. 557 works similar but not exactly like a 555. I looked at a 557 schematic and the cord unit is almost ide ntical.

Most 557s use single cords rather than cord pairs. I think it is the 557B that has single cords. These were used in telephone answering bureaus.

[trainman]

I think the 557A,  even though it is an answering service board, will also work as a PBX. Its the 557B that is strictly for Answering Service work, if I recall correctly.

[RB]

Good progress over weekend.
I think I have the right side working like it is supposed to.
pick up, plug in, left lite on. hang up, left lite off. always has power.
The S relay locks, the RB relay locks, and the AS relay locks.
when I hang up, AS and RB release,  S  relay stays locked.??
is that proper operation?
the left side, different story. with both station jacks wired to provide ground to the sleeve when connected, pick up left phone, has power. plug in and kills everything.
I believe, according to the schematic, the sleeve wiring, requires a ground for the right sleeve, but positive for the left? at least it works better that way.
still having problems with left side.
also, much to my dismay, I have lost comm between the two phones, with or without the cord set.
not sure what's  goin on there? both get power, both can hear own voice in rec. but will not talk to each other???
I had the cs relay, and the T relay operating also.
I think i need to solve the polarity problem with the sleeves, then it may be ok??
Next problem, the power. lookin at the pic, there is a cap in line with the top power run. not sure if that is needed, prob. but, when I release the AS relay, the double dim lites go out. still have not solved that one. maybe needs that cap for the pin 11 power??

[trainman]

Even when there is no power on. Tip and ring still go through. Why not just use it to connect two local.battery phones together?