Author Topic: 10 Line Cordless Magneto Switchboard  (Read 11053 times)

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #15 on: July 18, 2014, 12:13:14 PM »
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?
I suspect NE, but who knows. Not enough is marked in it.

The original operator's set used with this I suspect was a dial-less 211 - the leads come out the left hand side through a hole and around that hole is the familiar screw pattern of a 211 mount.

Dave
« Last Edit: July 23, 2014, 02:11:49 PM by DavePEI »
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

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #16 on: July 18, 2014, 12:15:24 PM »

Perhaps there is some evidence of two old screw holes in the base board corner?
Not a mark at all. The only holes in the board are filled (as in used).

Dave
« Last Edit: July 23, 2014, 02:11:32 PM by DavePEI »
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

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #17 on: July 18, 2014, 12:23:58 PM »
I suspect NE, but who knows. Not enough is marked in it.

The original operator's set used with this I suspect was a dial-less 211 - the leads come out the left hand side through a hole and around that hole is the familiar screw pattern of a 211 mount.

Dave

NE marked their coils MM-DD-YY, not quarter-Year.

I think the "original" operator station was undoubtably a desk stand, but many switchboards indeed were retrofitted with the hanging types on the side to remove clutter from the desk. Perhaps this happened the same time the coil was installed.
« Last Edit: July 23, 2014, 02:11:07 PM by DavePEI »

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #18 on: July 18, 2014, 12:28:03 PM »
I suspect NE, but who knows. Not enough is marked in it.

The original operator's set used with this I suspect was a dial-less 211 - the leads come out the left hand side through a hole and around that hole is the familiar screw pattern of a 211 mount.

Dave

NE marked their coils MM-DD-YY, not quarter-Year.

I think the "original" operator station was undoubtably a desk stand, but many switchboards indeed were retrofitted with the hanging types on the side to remove clutter from the desk. Perhaps this happened the same time the coil was installed.
Did you have a peek inside the one at the show to see how it was equipped?

I should point out that very few connections in the board use spades - most are connected directly to the terminals - and some directly soldered.

Dave
« Last Edit: July 23, 2014, 02:10:49 PM by DavePEI »
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

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #19 on: July 18, 2014, 12:56:01 PM »
What would the terminal board in the bottom left of the case be for?

Dave
« Last Edit: July 23, 2014, 02:10:34 PM by DavePEI »
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

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #20 on: July 18, 2014, 01:00:08 PM »

Did you have a peek inside the one at the show to see how it was equipped?

Dave

No, don't recall.... but I remember revisiting it with my camera.  I suppose you could contact the owner, I don't recall who it was, but I am sure others do.
« Last Edit: July 23, 2014, 02:10:16 PM by DavePEI »

unbeldi

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #21 on: July 18, 2014, 01:01:35 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.
« Last Edit: July 23, 2014, 02:09:57 PM by DavePEI »

unbeldi

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #22 on: July 18, 2014, 01:07:50 PM »
I should point out that very few connections in the board use spades - most are connected directly to the terminals - and some directly soldered.

Dave

I would expect that actually. The terminals with the large nuts are meant for direct wire connections.  But in the case of the induction coil, if it were original, I think they would have put spades there.  The 315H/J/etc. subsets used spades only on the generator. The whole harness was soldered together.
« Last Edit: July 23, 2014, 02:09:37 PM by DavePEI »

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #23 on: July 18, 2014, 01:30:44 PM »

Did you have a peek inside the one at the show to see how it was equipped?

Dave

No, don't recall.... but I remember revisiting it with my camera.  I suppose you could contact the owner, I don't recall who it was, but I am sure others do.
It was Keith Hlavac, Paul Axman told me - I emailed Keith, but haven't heard back from him...

Dave
« Last Edit: July 23, 2014, 02:09:17 PM by DavePEI »
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

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #24 on: July 18, 2014, 01:33:28 PM »
I should point out that very few connections in the board use spades - most are connected directly to the terminals - and some directly soldered.

Dave

I would expect that actually. The terminals with the large nuts are meant for direct wire connections.  But in the case of the induction coil, if it were original, I think they would have put spades there.  The 315H/J/etc. subsets used spades only on the generator. The whole harness was soldered together.
Anyway, I was just back over looking at it, and I see no sign of any other mounting point. No spare holes, nothing...

Gotta g back over for a while and glue that other spot between the boards I couldn't get this morning.

Dave
« Last Edit: July 23, 2014, 02:08:55 PM by DavePEI »
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

Offline DavePEI

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4003
  • Telephone Museum of Prince Edward Island
    • The Telephone Museum of Prince Edward Island
Re: 10 Line Cordless Magneto Switchboard
« Reply #25 on: July 18, 2014, 02:46:20 PM »
Yes, that is a buzzer on the left hand side and not a capacitor. I just removed its cover. No markings, though... Found another place I had neglected to re-glue, so have that spot done, too.Also removed the sticker residue over the 211 mount. I will hav e to convert one of my spare 211s back to non dial then try to remember how to hook them up as a simple stand. Its been a very long time since I did that. Hopefully I can find  dial cover for it to close the dial mount hole.

I still have to re-solder that drop wire, but that is minor - just a matter of remembering to do it  :D

Tomorrow, I will begin its refinishing.

Gotta pick up some dowel - the top drops over 4 short dowels then has two screws which actually hold it to the board. Since both the dowels are missing, the old dowels must have gone AWOL along with the top. There are mating holes in the sides.

Dave
« Last Edit: July 23, 2014, 02:08:36 PM by DavePEI »
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

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #26 on: July 18, 2014, 04:00:42 PM »
This is not like wiring a simple stand, unless the induction coil in this board is used simply like a No. 13 coil, and that does not appear to be the case, because the A terminal is wired.  I like to speculate that not many collectors have ever wired a C or G-mount for pure LB  service with AST operation.

It should probably resemble something like this diagram.
This is based on a 307 set.  The 307 is a common-battery signaling circuit, and therefore must have the caps.
I think for LB operation the capacitors could just be bridged with wires, unless there is a need for the higher impedance that caps provide. This is unlikely for the 0.5MF cap, since it already has the 300 ohm resistance between A and C.

The hook switch contacts are designated HS1 through HS3.  HS1 would be taken care of by the front panel key, so HS2 and HS3 must be implemented in the telephone.  Now you have to figure out if all this can be done with only four wires in the mounting cord.

Battery power could be applied directly from the front panel key too, so the handset operation only needs three wires. The A-terminal connection is the same as the red handset wire, so nothing is needed. So, it seems indeed one would only needs three conductors.  HS2 can be served by the hookswitch, as could HS3 in principle, it could be moved to the black transmitter lead. It would be best to use the hook switch for HS3 in fact, so that the transmitter doesn't use power when the operator hangs up, but didn't disconnect her station on the switchboard.

« Last Edit: July 23, 2014, 02:08:17 PM by DavePEI »

Online poplar1

  • Hero Member
  • *****
  • Posts: 5772
  • 102C-6 = "Old Brass" Hand Telephone Set
Re: 10 Line Magneto Board
« Reply #27 on: July 18, 2014, 04:11:08 PM »
  I like to speculate that not many collectors have ever wired a C or G-mount for pure LB  service with AST operation.


Maybe not by collectors, but 211As (non dial G handset mtg + handset) were often attached to 415H and 400K Subsets in the field.
"C'est pas une restauration, c'est une rénovation."--François Martin.

unbeldi

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #28 on: July 18, 2014, 04:16:52 PM »
  I like to speculate that not many collectors have ever wired a C or G-mount for pure LB  service with AST operation.


Maybe not by collectors, but 211As (non dial G handset mtg + handset) were often attached to 415H and 400K Subsets in the field.

Yes, sure.  I agree with that. The configuration was certainly useful.
« Last Edit: July 23, 2014, 02:07:55 PM by DavePEI »

unbeldi

  • Guest
Re: 10 Line Cordless Magneto Switchboard
« Reply #29 on: July 18, 2014, 06:27:24 PM »

4 wires from telephone to subset (or switchboard)  and a 4-contact switch hook are sufficient for Anti-sidetone with Magneto Service.

Yes, I thought my explanations showed that.

Turns out, that the 400K subset seems to include the 0.5MF capacitor, at least acc. to a diagram I found, but I am not quite sure about the reason.  It must have something to do with balancing line capacitance, not just impedance.

I posted schematics for the 400K in another thread:  http://www.classicrotaryphones.com/forum/index.php?topic=12301.0
It's essentially the same as my diagram here.
« Last Edit: July 23, 2014, 02:07:08 PM by DavePEI »