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10 Line Cordless Magneto Switchboard

Started by DavePEI, July 15, 2014, 02:30:49 PM

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DavePEI

Nuther Load Today!

Another interesting load arrived today, This was a smaller load as the person carrying it for me had less room in their car than some of the others, but that didn't make it any less interesting.

Included was a neat little Stanley & Patterson anunciator, two NE 17C magneto test boxes, another Russian Princesse (Crouse-Hinds explosion proof phones), an ancient arrestor, and a number of interesting NE intercoms the same as one which came in an earlier shipment. Used as packing material were a bunch of NOS 7 foot switchboard cords!

The Russian Princess has the switchhook arranged for wall mounting.

Don tells me he had a lot more for the museum, and I am looking for more people coming to the Island to bring more down.

Here is a photo of today's lot!
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

unbeldi

#1
For comparison, here is a picture of a restored version of David's magneto switchboard.  I took this picture at the 2013 Lancaster show. David's board matches it perfectly, only his is more barn-fresh, unlike this restored version.

It is a Northern Electric cordless magneto switchboard with five talk circuits, ten magneto station loop circuits, and controls for one operator console.  The station circuits could be used as manual tie trunks just the same.

The orange switches connect a station to one of the first four talk circuits, up A and C, down B and D. The black switches of the bottom row have dual function, in the up position they connect a line to the fifth talk circuit (E), while in the down-position they ring a line when the generator is cranked at the same time by the attendant.
The five drops at the top are to indicate ring-off has occurred on an established talk circuit, to alert the attendant to tear down the circuit.  On later automatic cordless switchboards with lamps, this would be detected automatically when a station went on-hook; a relay would activate a lamp and sound a buzzer. With these manual boards, a station user had to crank the generator briefly after hanging up.
The second row of drops are alerts that a station user wants service. They crank their generator, and the attendant sees who is requesting it. She would connect her attendant console to the line with the orange key (up) on the bottom row to the requesting circuit (black up). On Dave's board the orange key is also black like all the keys of the bottom row.

The white keys are listening keys so the operator can connect to any talk circuit and intervene or simply listen to find out if the circuit was still in use, in case someone didn't ring-off their call.

Of course, the G-type hangup dial hand telephone, attached to this board at Lancaster, is an anachronistic modernization. However, from what I understand magneto boards were used in Canada much later on the average that in the US, but a dial on this board does seems a bit novel as it requires battery.

poplar1

#2
Catalog #5 (1923?) shows "No. 505 Cordless Type" switchboards "designed for both central battery and magneto service."

"505B"-- 3 trunks x 7 station lines-- Trunks connect to Central Battery manual office

"505C"-- 3 x 7 Private Branch Exchange Switchboard--Trunks connect to C.B. machine switching office

"10 Line Cordless Magneto Switchboard"--"equipped with 10 magneto station lines, any of which may be connected with a line from a magneto office for trunking purposes."
"C'est pas une restauration, c'est une rénovation."--François Martin.

DavePEI

#3
Quote from: unbeldi on July 16, 2014, 10:00:07 AM
For comparison, here is a picture of a restored version of David's magneto switchboard.  I took this picture at the 2013 Lancaster show. David's board matches it perfectly, only his is more barn-fresh, unlike this restored version.
Thanks, Karl! It will live again!
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

unbeldi

#4
There is some kind of designation stamped into the edge of the wood panel in the inside view. It may indicate the model number, or not. Starts with 5 in any case.

The same picture also shows the connections for the ten stations, T and R, as well as a few additional one, marked with plus and minus signs.  G and G1 are no doubt the generator connections, implying perhaps that an external generator feed could be used. I can't make out the designation for the two other terminal pairs. They have + and - characters, but this could be an indication that the same connecting block was also used for the common battery versions of the model. In any case, it seems one of them should be the operator console, unless there is an induction coil mounted somewhere else in the unit to which the console attaches directly.

That brings up another observation,  there does appear to be a 101-type induction coil further down inside the unit at the end of that thick harness. Likely that is a later addition for the operator console. Perhaps David can shine some light on that, and see if it is a 101 or a 104, who made it (WE or NE), and what its date is.

poplar1

#5
"The operator's telephone set includes a desk set with black finish complete with receiver, transmitter and cord and is operated by the key on the extreme right."

The photo shows a 20-type desk stand only; so, the induction coil would be inside the P.B.X. and the external talk battery for the operator's phone would be connected to terminals in the P.B.X.
"C'est pas une restauration, c'est une rénovation."--François Martin.

DavePEI

#6
Quote from: unbeldi on July 16, 2014, 11:57:28 AM
There is some kind of designation stamped into the edge of the wood panel in the inside view. It may indicate the model number, or not. Starts with 5 in any case.

That brings up another observation,  there does appear to be a 101-type induction coil further down inside the unit at the end of that thick harness. Likely that is a later addition for the operator console. Perhaps David can shine some light on that, and see if it is a 101 or a 104, who made it (WE or NE), and what its date is.
Ah, now that is how bad my eyes are now - I never noticed the designation when I was looking right at it. Just got another shot in my left eye this morning....

I will have to have a really good look at it with a magnifying glass and try to make it out... Funny thing is I had looked for markers that would help to identify it and completely missed that...

Now, about the induction coil.... Unless I can make it out from the top, that will have to wait until I can re-glue the laminates between boards in the cabinet. The reason is, if I unscrew practically anything at this stage, the boards will fall onto the table around it like a stack of cordwood. Every bit of glue on it has failed. Thankfully, other than needing refinishing, the wood itself is in good shape - it is only that the glue has failed.

So, being overly cautious, perhaps anal by nature about things like that I'd rather take my time and re-glue it side by side before I take it apart to the extent needed to see the coil better. However, I promise to take a look at it tonight to see if I can make out anything without going to the extent of beginning to disassemble it.

The problem is, as you can imagine, is with this amount of stuff arriving within the past couple of weeks, and just as much more expected, I have to spend my time now going through and cataloging it all, safely storing it, and/or putting it on display, and tons of cleaning and minor repairs! It is a bit of a nightmare, but one I am thrilled to have. I have never had a find like this before, and I one never expect to have again. The photos I have posted here are only the tip of the iceburg.

So with much, tonight I may be able to find the info you are looking for. I do have a magnifying glass over in the office, so I hope it will allow me to read the numbers. Unfortunately, I can see almost nothing out of my left eye right now after the injection in it.

I also aside from sorting and cleaning items, hope to find time to call a local carpenter to see if he has a suitable piece of oak of maple in his scrap pile to make a new lid out of. He does some furniture making, so there is a possibility. I am not really certain what wood it is made of. but I am hoping I will be able to get an old piece of solid full dimension lumber from him I can use to make the new top.

I don't think I have had so much fun with any one particular piece of equipment since I got my 1240 switchboard and got it going! Thanks, Karl and all!

Update: I just had a look at the unreduced photo of the board I took yesterday, and on another photo I didn't use, it shows what I think is the full number (to be verified latet). It is either 521 or 5.1 as in the photo below... This photo shows a little bit further to the right of the other.

Dave
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

unbeldi

#7
I have found that I observe much better on pictures, if they are good, than on the items directly often. A picture provides some kind of steady focus and lack of distraction by surroundings, I suppose.

No rush with the identifications... You have a lot to cover already.

unbeldi

#8
Quote from: DavePEI on July 16, 2014, 03:24:42 PM


Update: I just had a look at the unreduced photo of the board I took yesterday, and on another photo I didn't use, it shows what I think is the full number (to be verified latet). It is either 52 or 5.1 as in the photo below... This photo shows a little bit further to the right of the other.

Dave

How did you arrive at 52 as a possibility? Perhaps this image is again too low in resolution....
In fact I know it is, because there is already too much information loss for image enhancements. It's only 72dpi.

DavePEI

#9
Quote from: unbeldi on July 17, 2014, 03:06:03 PM
Quote from: DavePEI on July 16, 2014, 03:24:42 PM
How did you arrive at 52 as a possibility? Perhaps this image is again too low in resolution....
In fact I know it is, because there is already too much information loss for image enhancements. It's only 72dpi.
Don't forget, I have the un reduced photo here at full resolution. But, it won't help you as I said, it is either 5.1 with the ) looking like an o, or 521 with only the lower portion of the 2 showing. If it was a 2, the punch was on an angle so didn't cut the upper portion, but there are vestiges which look as though it could have been a 2. I had another look at it today with a high powered magnifying glass and I stick with that. The only one questionable at all is the "o" or "20".

The one thing I did discover today is that the glue isn't as bad as I had previously thought. There are 3 seams which have come undone, but I should be able to re-glue them tomorrow without a lot of trouble.

I picked up a piece of birch plywood to make a temporary lid for it until I find a piece of hardwood to do it. It was going to cost me $100 to get a piece joined with biscuits large enough from hardwood. So hopefully this will do well enough to serve for the time being. Hopefully I can find a piece off some old furniture in a yard sale this summer to make the final top.

The ply was only $5. Birch plywood takes a wonderful finish - my desk here is made of stained and varnished birch plywood, and back when we were selling some of my parent's antique furniture, a lady asked me how much I wanted for the "lovely antique desk"  :)

Another advantage of my using it is I can use it to get the holes in the correct position and then I can use it as a template for the final top. I am thinking of dropping cut nails in the old screw holes to mark the correct position of the screw holes so that the new top will screw into the existing holes.

I did drop the front today, but there wasn't have time to take photos (I had the camera over there, but the memory card was in this house) and I had to leave direct from there for the lumber store. I will vacuum the inside and post a photo of it tomorrow.

Ny the way, the overall dimensions of the top and bottom of the board are 19.5 x 17 inches. I didn't measure the height as I was in a rush to get to the hardware store.

Dave
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

DavePEI

#10
For anyone who has been following the switchboard, I finally got three of the sections needing re-gluing done this morning, and it is now clamped and drying.

After it dries, I have one more spot to re-glue, one which would have been difficult to clamp at the same time as the others.

I took a couple of photos of the board while I had it open you might find interesting, one showing from the door back, and one showing the door equipment. I also took a photo of the coil, which might be of interest. It is indeed a 104A and carries the date 1943...

Dave
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

unbeldi

#11
Ok, good to know that the coil was indeed a 104, which is what a local battery system should have. A 101 would have probably shown that some collector bastardized the box. This seems very original and makes sense. I am sure these boards were still in use in the 40s, and even a decade later.

The 104 is also missing the resistor, which is right on, because it was used for the attendant station, and didn't need extra loop compensation, ergo they saved the component altogether. This might just indicate that this was a factory installed feature. I think the terminal for attaching the operator set are on the left, the four terminals on the cabinet wall, it was an AST instrument.

I see what looks like a buzzer mounted on the inside left? Or is this a condenser for the operator station?  [PS:  Given the location, I'd say it's a condenser.]

Somewhere there should probably be a key to toggle the generator source from local to remote feed. Is that a key on right or a jack?

unbeldi

#12
Some wires are broken off from their terminations on the drops it seems.

#5 connecting circuit ring-off drop. brown or orange wire.

unbeldi

#13
I think I have to modify my observation about the missing resistor on the 104A coil.  I think this is an earlier version which had the extra A-terminal resistance implemented in the coil by means of a non-inductive winding. This can be seen by the fact that the A-terminal actually has a lead going into the coil. The compensation is between A and C.  In this application it therefore seems wrong that the A-terminal would have the wire connected and not C.

It is also interesting to note that the wires terminated on the 101A do not have spade lugs, but are bare wires.  Perhaps the unit was upgraded from a hardwired 113 coil?

I am wondering now who made this board. The 104A coil appears to me made by Western Electric, not NE.  But if the coil was an upgrade, could someone have used WE parts?

Hmm, is a four-conductor mounting cord enough to connect an LB-AST operator instrument to this switchboard?

unbeldi

#14
Quote from: unbeldi on July 18, 2014, 11:05:43 AM
I think I have to modify my observation about the missing resistor on the 104A coil.  I think this is an earlier version which had the extra A-terminal resistance implemented in the coil by means of a non-inductive winding. This can be seen by the fact that the A-terminal actually has a lead going into the coil. The compensation is between A and C.  In this application it therefore seems wrong that the A-terminal would have the wire connected and not C.

It is also interesting to note that the wires terminated on the 101A do not have spade lugs, but are bare wires.  Perhaps the unit was upgraded from a hardwired 113 coil?

I am wondering now who made this board. The 104A coil appears to me made by Western Electric, not NE.  But if the coil was an upgrade, could someone have used WE parts?

Hmm, is a four-conductor mounting cord enough to connect an LB-AST operator instrument to this switchboard?

My suspicion is that the 104A is a retro fit. Why would they have mounted it in the middle of the back side? It probably was a No. 13 sidetone coil (not 113) mounted on the base board and the harness needed to be this long to reached down there. For that, a four-conductor mounting cord was ok, just like a 315-type subset. This would also not require a condenser, and the black box indeed would be a buzzer.

Perhaps there is some evidence of two old screw holes in the base board corner?