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NEWBIE WeCo 550-C PBX Info wanted

Started by BigBird0000, June 17, 2017, 11:56:26 AM

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Alex G. Bell

Quote from: BigBird0000 on July 23, 2017, 07:20:54 PM
I've been having fun with the kids and the PBX.

Is there an easy way to connect the ring generator to the PBX so the magneto does not need to be turned to signal?

Those PBX operators must have been pumped!
Trust me!  They weren't.  The magneto was there as a backup because in the days when cord switchboards were first used most commercial electric power, if available at all, was DC therefore not easily converted to the voltages required by a switchboard except by using high-maintenance motor-generator sets. 

Consequently, spare cable pairs from the Central Office to the PBX location were used for reliability and low maintenance cost to charge batteries to provide the DC and feed CO ringing current to the PBX.  The batteries would keep it going for a while if the DC charging feed failed and the hand generator if the ringing feed failed.

Yes, of course you can and should connect a ringing generator.  I may have to review the history of this thread to see whether I have sufficient information to advise you as to where to connect the ringing source and cannot do that now. 

ISTR you posted photos identifying the terminals so I may have already answered this question earlier.

BigBird0000

Hi Alex,

I have attached a pic of the back of pbx with the black lamp wire cords going to voltage and ring gen.
(I even used a tripod this time)!
--alan

Alex G. Bell

You are feeding 90V 20Hz AC to the GEN +/- and G terminals and still are unable to ring an extension by operating the ringing key?

Does a telephone connected directly to these terminals ring?

There should be a GEN transfer twist key for switching between the hand generator and external source.  It must be set properly.  There should also be an Edison base bulb socket with a resistance lamp screwed in.  Is the lamp there?  Is the filament continuous?  (check continuity by any of a number of methods or bypass the lamp temporarily with a jumper.

BigBird0000

Once again Alex, you are correct!
I had all the on/off switches set OPPOSITE of what they should be.
(The writing is rubbed off on my PBX, I need to restore that section.

It does sound good to hear those old metal real ringers!

:D

Alex G. Bell

Quote from: BigBird0000 on July 25, 2017, 07:25:03 PM
Once again Alex, you are correct!
I had all the on/off switches set OPPOSITE of what they should be.
(The writing is rubbed off on my PBX, I need to restore that section.

It does sound good to hear those old metal real ringers!

:D
So it's working from the ringing supply now instead of the hand generator?

BigBird0000

Yes... it is working on both.
I will use the tellabs generator, I'll have the kids still use the crank!

Thanks Very Much Alex !!!!

Alex G. Bell

Quote from: BigBird0000 on July 25, 2017, 08:40:08 PM
Yes... it is working on both.
I will use the tellabs generator, I'll have the kids still use the crank!

Thanks Very Much Alex !!!!
Very good. You're welcome. 

Please post a close up photo of this cluster of keys.  I'd have expected engraved nickel plated escutcheon plates above these keys designating their functions, rather than ink markings, and tiny holes remaining above them from the brass escutcheon pins (tiny round headed nails) which originally attached the designation plates once they were removed.

BigBird0000

Looks like the letters were engraved, don't see nail holes.
From the "GEN" it looks like they were white filled.

unbeldi

#38
Yes, the questionable key is the "Buzzer" key, often also called the "Night-Alarm" key.

Most common battery PBX switchboards, corded or cordless, of the time have basically three controls, other than those that operate on each specific station line or trunk line.

Battery (on/off):  This key disconnects the switchboard from the DC power feed, which came either from a local supply (battery or generator), or from a wire pair from the central office. It was set to the off position during times when the PBX attendant was NOT available at all, e.g. during night time, and weekends.  When off, the PBX could typically be set up for night connections, so that any incoming calls ring directly at a PBX station, rather than announce the call at the switchboard.

- Night Alarm or Buzzer (on/off):  This key is operated when the attendant is available, but away or distracted from the switchboard, to sound an audible alarm, typically a mechanical buzzer, when any line lamp, or any other supervisory lamp (talk circuit, trunk hold circuit) turns on.  This permits the attendant to do other work without being focussed at the switchboard lamps.

- Generator:  This key selects the source of ringing current applied to PBX stations.  It has two positions,  power generator (P.G.) and hand generator (H.G).   For P.G.  operation the ringing current comes from either a local ringing power generator, or from a remote feed of ringing current from the central office.  This was the normal setting in probably most installation scenarios.  When this power source was not available, the control was set to obtain ringing current from the built-in hand generator. Thus, the attendant had to operate the ringing key as well as operate the hand generator at the same time.

On these Western Electric switchboards, these keys were turn-keys with a knob from early on, as on your board.  But it was also common to use level-type keys.

Alex G. Bell

Quote from: BigBird0000 on July 26, 2017, 12:59:57 PM
Looks like the letters were engraved, don't see nail holes.
From the "GEN" it looks like they were white filled.
Right.  On 551s these keys are on the cabinet to conserve keyshelf space, so metal escutcheons are nailed into the wood.  I forgot where they were on a 550.  Phenolic key escutcheons that are an integral part of the key assembly would have to be engraved and filled with white paint. 

You might be able to get an engraver who makes phenolic name plates to re-engrave them.  Normally engravers work on a phenolic sandwich with a white middle layer and engrave through the top layer to expose the white middle layer to reveal the letters in a contrasting color so this would require filling with white paint.

BigBird0000

Unbeldi & Alex,

Thank you both for the info. Unbeldi, the descriptions off the switches help. :)

Alex, I have some white paint that I have used in Radio and Jukebox restorations. I normally use a toothpick, and put paint in. When Dry I repeat again a few times. Lastly, I put the paint in (think pour over, but on a lesser scale) and wipe extra paint off. Works great, I will try that before going to an engraver.

Alex G. Bell

Quote from: BigBird0000 on July 26, 2017, 02:15:06 PM
Unbeldi & Alex,

Thank you both for the info. Unbeldi, the descriptions off the switches help. :)

Alex, I have some white paint that I have used in Radio and Jukebox restorations. I normally use a toothpick, and put paint in. When Dry I repeat again a few times. Lastly, I put the paint in (think pour over, but on a lesser scale) and wipe extra paint off. Works great, I will try that before going to an engraver.
Sure.  If the engraving seems deep enough to hold the paint, by all means try that first. 

I'm not sure whether an engraver can follow pre-existing engraving.  They probably use a stencil or pantograph and may not be able to retrace existing engraving, only create new engraving according to the size and style of their tool set, which might not match the original.   So if the original is still visible best to just refill it.

BigBird0000

I'm not sure if a jewelry engraver can. You are thinking old style, I'm sure most of them use
computers now so any minimum wage worker can do it. A real jewelry craftsman would be hard to find.

But I was thinking if I had to, a Gun Engraver might.

I'll let you know what happens.

TelePlay

Quote from: BigBird0000 on July 26, 2017, 02:15:06 PM
I have some white paint that I have used in Radio and Jukebox restorations. I normally use a toothpick, and put paint in. When Dry I repeat again a few times. Lastly, I put the paint in (think pour over, but on a lesser scale) and wipe extra paint off. Works great, I will try that before going to an engraver.

I've done this many times on metal and plastic. The engraved area must be free of dirt and oils. Any kind of paint will work but I usually go with a ceramic enamel. Just slobber it on over the engraving, press it into the engraving with Saran Wrap over a finger, gently wipe off the excess, let it sit for 15-30 minutes and then use the paints solvent on a flat objects to wipe the almost dried paint off of the surface without removing it from the engraving. I've successfully filled some very light and fine engraved letters that way. Learned that process at the Antique Radio Forum.

If you don't like the results, you can then go to an engraver, gun or trophy or jeweler.

Alex G. Bell

Quote from: BigBird0000 on July 26, 2017, 03:04:50 PM
I'm not sure if a jewelry engraver can. You are thinking old style, I'm sure most of them use
computers now so any minimum wage worker can do it. A real jewelry craftsman would be hard to find.

But I was thinking if I had to, a Gun Engraver might.

I'll let you know what happens.
Yes, I suppose so.  Please do.