News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

10 Line Cordless Magneto Switchboard

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

Previous topic - Next topic

DavePEI

#30
As of this morning, I have the first coat of Howard's Walnut Restor-A-Finish on my board. All loose joints are re-glued and it is beginning to look great! A few more coats of Thompson's, and a few applications of paste wax, and it will look like new!

I also found and installed a magneto crank on it.

Not bad for a free cordless board with no shipping cost!

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

#31
Quote from: DavePEI on July 18, 2014, 08:37:32 PM
Ok, here is something which may lead to a definitive answer as to the origin on this board.

As I had mentioned, there is very little marked inside the board. But just about everything is Western/Northern Electric style. We do know a very similar board was made by NE due to Keith's NE board...

BUt I have discovered one number which may be a clue? It is located on the frame surrounding the keys on the back of the door. It is T 75023 G3 - anyone see any significance to this?

Dave

This stamp looks awfully modern. Like a refurbishing stamp.  Could it be Jan 23, 1974?
Since someone applied it there must be some significance.  It was applied with a rubber stamp by hand, from the varying thickness of characters.

unbeldi

#32
Quote from: DavePEI on July 19, 2014, 08:16:27 AM
As of this morning, I have the first coat of Howard's Walnut Restor-A-Finish on my board. All loose joints are re-glued and it is beginning to look great! A few more coats of Thompson's, and a few applications of paste wax, and it will look like new!

I also found and installed a magneto crank on it.

Not bad for a free cordless board with no shipping cost!

Dave
Is the generator still strong enough to ring a phone? Did you measure its output?
Is that a No. 47 or 48 generator?  Those were the largest WE/NE made, I believe, for heavy loads.

DavePEI

#33
Quote from: unbeldi on July 19, 2014, 09:08:28 AM
Quote from: DavePEI on July 19, 2014, 08:16:27 AM
As of this morning, I have the first coat of Howard's Walnut Restor-A-Finish on my board. All loose joints are re-glued and it is beginning to look great! A few more coats of Thompson's, and a few applications of paste wax, and it will look like new!

I also found and installed a magneto crank on it.

Not bad for a free cordless board with no shipping cost!

Dave
Is the generator still strong enough to ring a phone? Did you measure its output?
Is that a No. 47 or 48 generator?  Those were the largest WE/NE made, I believe, for heavy loads.
I didn't measure its output, but it rings phones no problem. It is an NE 48A - decal on back side bottom edge of generator. Magnets are a bit out of line, and I suspect its output will improve more when I line them up. I have noticed that before in other sets - they tend to slip in the retainer at the bottom of the magneto frame if it isn't bolted in securely.

I got the first coat of stain on it a while ago, and made up the temporary Birch plywood top for it, got the dowels and screws in. I still have to take the top over here and round its edges and sand it, but it is looking better with a top. My router is over here and I wanted to try to match the stain colour first before I bothered. Perhaps tonight...

Pi will all require light sanding between stain and paste wax coats. There are some areas I will have to re-stain to get the colour consistent. Of course, the stain is still wet in this photo, so it will even out as it dries. Looks much better later in the evening when it dried completely.

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

#34
As we have so far been unable to ascertain the board's maker, I though I would mention this.

I had previously thought it was a "This Side Up" symbol, but on the outside of the board, at the center top, there is a thick blackarrow inside a "C". Does this lead towards any determination of a manufacturer? It is not a symbol I am familiar with.

I have decided to varnish the board rather than using paste was. I love the finish a paste was gives, but the varnish gives a much more resilient finish, so I have decived to go with it. I finished staining last night (other than the top which I still need to route the edges on), and will be putting on the first coat of varnish this morning....

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

#35
Quote from: DavePEI on July 20, 2014, 05:08:55 AM
I had previously thought it was a "This Side Up" symbol, but on the outside of the board, at the center top, there is a thick blackarrow inside a "C". Does this lead towards any determination of a manufacturer? It is not a symbol I am familiar with.
A TCI posting by Steve C. reminded me of this. When I was young, I used to see this symbol on Canadian military goods - it meant "Canadian Issue". I haven't seen that mark since I was a child, and I had totally forgotten about it and what it meant. It was called a Broad-arrow "C". I knew it looked familiar and for that reason, I was hoping it might direct us to a manufacturer.

You would often see the logo on things like gun stocks of guns issued to soldiers.

So, while we may not have learned anything about manufacturer of the board, we have learned something about its history, that it was manufactured during WWII (See date on coil) for the Canadian Military. So it becomes just an interesting little tidbit about the board's history.

Neat, though...

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

#36
Update: As the stain looked like it could use some more drying time, I decided to go ahead with the temporary lid for the board... All four edges had to be rounded over with a router bit. As I did it, the bit broke - the rotary bearing on the bottom of the bit which guides it broke off, allowing the bit to dig into the wood.

As a result, the edge was much more uneven than it should be. Before the good hardwood for the final top arrives, I will have to buy a new bit. The bad edges were cut off, with the result the temporary lid won't have the overhang on the sides the final lid will have, but otherwise it will look and function fine.

I got it sanded smooth this evening, and got it stained. With luck the more porous Birch plywood making up the temporary lid will soak in the stain faster than the close grain of the board itself, and I should be able to begin varnishing the whole board  in the morning.

Once I get the board done, I will begin restoration on the Police and the fire call boxes which also came in this batch. I also have the little Stanley & Patterson anunciator which came in the latest batch I want to work on, as well as the Russian Princesses  :)

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

#37
Keith Hlavacs has the twin to my switchboard down to all details including the broad-arrow C on the back, matching dates, etc.

Keith has just sent me the following scans of the diagrams on the underside of his top cover. Mine, of course is missing these, as the cover was missing.

In a subsequent email, Keith told me he may try doing it on a machine they have at work to see if he can get better results.

Here are copies of his scans. If I can improve them later, I will. I am in the museum workshop right now working on the board. I will see later if I can improve the scans.

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

#38
Certainly answers a lot !
The 104A induction coil is original by design and it was supposed to have a 211 hangup telephone on its side!

Even with some corrections, the diagram is still pretty hard to read, as far as text is concerned. It would have been great if Keith had laid it on a scanner since the it's the top board from what I understand that can be removed entirely.

unbeldi

#39
Here is the operator telephone set circuit acc. to the diagram.

Terminals are drawn as close as possible to the diagram. In a circuit diagram this is sometimes a little difficult, but worked out ok.
1, 2, 3, 4 are connection terminals for the OPR TEL SET on the inside wall. Most of the internal terminals inside the G1/211 are there too.

Essentially it is identical to the diagram I drew earlier here based on a 307.  The capacitors are not needed in this application, and we see that NE left them out too.
This circuit was also used in the 400K subscriber set for use with a D1/202H, see circuit description here: http://www.classicrotaryphones.com/forum/index.php?topic=12301.0

unbeldi

#40
Quote from: unbeldi on July 18, 2014, 01:01:35 PM
Quote from: DavePEI on July 18, 2014, 12:56:01 PM
What would the terminal board in the bottom left of the case be for?

Dave
Good question, I have been peeking at it too.  Six pairs. Tracing the wires would probably tell a story.

I think the diagram tells me that this 31A connecting block on the base is for expanding the switchboard.
The twelve conductors form a sort of 'bus' that is common to all line circuits, and thus can be extended to another board to operate 20, or even more, magneto lines on the same five talk circuits.

unbeldi

#41
Block diagram of circuit parts:

unbeldi

#42
Quote from: unbeldi on July 22, 2014, 12:23:05 PM
I think the diagram tells me that this 31A connecting block on the base is for expanding the switchboard.
The twelve conductors form a sort of 'bus' that is common to all line circuits, and thus can be extended to another board to operate 20, or even more, magneto lines on the same five talk circuits.

Hmm, looking over the board pics again, it seems to me that none of the talk circuit drops were wired completely in this board. There is always one lead missing, and a wire appears to be stored in a sleeve close by.  I think this is exactly the kind of thing one would do when the intent is to use the board as an extension board to another unit.  You wouldn't want two drops falling, and having to restore them, for every termination.

DavePEI

#43
Quote from: unbeldi on July 22, 2014, 02:37:09 PM
Quote from: unbeldi on July 22, 2014, 12:23:05 PM
I think the diagram tells me that this 31A connecting block on the base is for expanding the switchboard.
The twelve conductors form a sort of 'bus' that is common to all line circuits, and thus can be extended to another board to operate 20, or even more, magneto lines on the same five talk circuits.

Hmm, looking over the board pics again, it seems to me that none of the talk circuit drops were wired completely in this board. There is always one lead missing, and a wire appears to be stored in a sleeve close by.  I think this is exactly the kind of thing one would do when the intent is to use the board as an extension board to another unit.  You wouldn't want two drops falling, and having to restore them, for every termination.


My gosh, you have good eyes! I have the board here and didn't even notice that. Easy fix, though.... Been concentrating too much on refinishing it... The two front border pieces are proving to be quite a problem getting an even finish on. I The rest turned out fine....

This part was more weathered than the rest of the board, causing the boards to be rougher on the surface. I think I will strip them down again and give them a really good sanding...

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

#44
Quote from: DavePEI on July 22, 2014, 03:48:18 PM
My gosh, you have good eyes! I have the board here and didn't even notice that. Easy fix, though.... Been concentrating too much on refinishing it...
...
I am not distracted by all the work you're putting in. I am an armchair investigator, LOL, picking out only the things that interest me from time to time.