Author Topic: Western Electric 2EB dial  (Read 491 times)

Offline waynet7

  • *
  • Posts: 27
Western Electric 2EB dial
« on: May 20, 2017, 09:19:07 AM »
I'll get pics up when I get back from vacation, but I was wondering if anyone has encountered a 2eb dial before. The outside is stamped 'patent applied for' and the regulator is not notched to allow adjustment. Looks like an early No. 2. Has a 132b notchless number plate. Thanks!

Offline unbeldi

  • Hero Member
  • *****
  • Posts: 5584
  • opus in senio
Re: Western Electric 2EB dial
« Reply #1 on: May 20, 2017, 10:29:24 AM »
The 2E dials were for use in switchboards and had one transfer switch in the off-normal set, which was isolated from the pulsing pair (Y-B).  That means, the GN terminal was switched from W to R when operated.  Dial speed was 10 pps.
The 2E came in 2EA, 2EB, 2EC, 2ED, 2EE, and 2EG number plate configurations.
It was replaced by 4E(ABDE), 5E(ABDE), and 6E dials.

Offline waynet7

  • *
  • Posts: 27
Re: Western Electric 2EB dial
« Reply #2 on: May 20, 2017, 10:44:16 AM »
Thanks! I am considering salvaging the number plate for a 2hb since this dial is apparently useless for calls.

Offline unbeldi

  • Hero Member
  • *****
  • Posts: 5584
  • opus in senio
Re: Western Electric 2EB dial
« Reply #3 on: May 20, 2017, 11:04:40 AM »
Functionally, it would be sufficient only for a candlestick that normally uses a 2A dial, by bridging the B and R terminals.  For a handset telephone, it is insufficient.

Indeed, the number plate would nicely complement a 2HB dial on B1 handset mounting.

Does the dial have a broad, but twisted or slanted, finger stop ?
« Last Edit: May 20, 2017, 11:06:42 AM by unbeldi »

Offline waynet7

  • *
  • Posts: 27
Re: Western Electric 2EB dial
« Reply #4 on: May 20, 2017, 11:17:31 AM »
A B1 is exactly what the dial was mounted on, but not wired in. I will put up some pics when I get home next week and have the dial in hand.

Offline unbeldi

  • Hero Member
  • *****
  • Posts: 5584
  • opus in senio
Re: Western Electric 2EB dial
« Reply #5 on: May 20, 2017, 11:27:12 AM »
It is conceivable perhaps that a B1 was used as the attendant's telephone set of a PBX or other switchboard, in which case that dial is correct and sufficient if at the same time an E2 handset was used, with a four-conductor handset cord.

But in most cases, someone probably much later, thought to convert a manual B1 for looks to a dial instrument with a discovered old dial.


Alex G. Bell

  • Guest
Re: Western Electric 2EB dial
« Reply #6 on: May 20, 2017, 03:07:30 PM »
Functionally, it would be sufficient only for a candlestick that normally uses a 2A dial, by bridging the B and R terminals.  For a handset telephone, it is insufficient.

Indeed, the number plate would nicely complement a 2HB dial on B1 handset mounting.
However the contact set could be swapped with one from a 5H dial, effectively converting the 2E to a 2H without making a permanent modification.

Offline unbeldi

  • Hero Member
  • *****
  • Posts: 5584
  • opus in senio
Re: Western Electric 2EB dial
« Reply #7 on: May 20, 2017, 03:36:51 PM »
However the contact set could be swapped with one from a 5H dial, effectively converting the 2E to a 2H without making a permanent modification.

Well, have you tried it ?
While the contact assembly indeed fits, the precise geometry of the pulse pawl w/r/t the switch leaves is different enough so that they need to be bent considerably to reestablished acceptable break ratio; often the pulse switch barely opens without such adjustment.
Finally, the modification is visible externally, by not having the proper finger stop with the 2HB stamping.


Alex G. Bell

  • Guest
Re: Western Electric 2EB dial
« Reply #8 on: May 22, 2017, 02:27:39 PM »
Well, have you tried it ?
While the contact assembly indeed fits, the precise geometry of the pulse pawl w/r/t the switch leaves is different enough so that they need to be bent considerably to reestablished acceptable break ratio; often the pulse switch barely opens without such adjustment.
Finally, the modification is visible externally, by not having the proper finger stop with the 2HB stamping.
Have not tried it and BSPs instruct craftspeople not to swap contact sets because impulse ratio may be affected and there was no way to do that in the field, only speed adjustment.  That said, I've seen and own (IIRC) #4 dials with both single point and bifurcated contact sets which I have reason to believe did not pass through the hands of an eBay seller or phone collector but were refurbished that way in the factory or perhaps produced that way leading up to the transition to #5 dials.   

While I know that some switchboard dials use molded non-metallic impulsing pawls rather than metal with insulating sleeve, I believe that contact sets should be relatively interchangeable with the proviso that adjustment of the M/B ratio be performed after the swap.  I'll look into this issue more carefully when time permits.

Subject to correcting the impulse ratio and notwithstanding incorrect marking on #2 fingerstops, swapping is a method which at least can provide a means to make #2 dials electrically compatible with handset circuits rather than bastardizing circuit operation.

Offline poplar1

  • Hero Member
  • *****
  • Posts: 5551
  • 102C-6 = "Old Brass" Hand Telephone Set
Re: Western Electric 2EB dial
« Reply #9 on: May 22, 2017, 03:47:49 PM »
Have not tried it and BSPs instruct craftspeople not to swap contact sets because impulse ratio may be affected and there was no way to do that in the field, only speed adjustment.  That said, I've seen and own (IIRC) #4 dials with both single point and bifurcated contact sets which I have reason to believe did not pass through the hands of an eBay seller or phone collector but were refurbished that way in the factory or perhaps produced that way leading up to the transition to #5 dials.   
 

These "conversions"  turn up often on 302s -- both on sets that were refurbished at the W.E. repair shops, and on "matching date" sets (esp. 1941). By "matching date", I mean that all the dates -- cords, transmitter unit, baseplate, etc. -- were new except for the converted dial, but the conversion date on the dial was close to the date of the new parts.

Here is a 2A that was converted to a 4H. http://www.ebay.com/itm/152551079251

It is a late 1920s 2A dial (Y BK BB W) that was converted to a 4H (W Y BK BB R) in 1939. (Not early 20s because the patent dates on the back rather than the rim.) Note that the original "W" terminal has been restamped "R" in vermilion ink:



"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline poplar1

  • Hero Member
  • *****
  • Posts: 5551
  • 102C-6 = "Old Brass" Hand Telephone Set
Re: Western Electric 2EB dial
« Reply #10 on: May 22, 2017, 04:03:43 PM »
Here is another 2A > 4H conversion. This one has the W to the left of Y, as on a 5H dial.  It also has "Twin Contacts" (bifurcated W/BB contact springs), as on a 5H-type dial. However, the contact springs are NOT exactly the same as those on a 5H! (Notice the 2 offsets on the lowest spring.)

Note the holes on the dial case where the external finger stop of the 2A was replaced with an internal finger stop, so that the dial could be mounted on a D1 handset mounting (202) or H1 tel set mtg. (302), both of which have recessed dials:

http://www.ebay.com/itm/1938-4H-Western-Electric-telephone-dial-phone-part-/332230333983

I have been told that it was necessary to enlarge the hole below the terminal strip -- at least for those with the W on the left side -- when installing these later type bifurcated contact springs on  a 2A (or 4H??)...does anyone know if this is true?
« Last Edit: May 22, 2017, 04:06:05 PM by poplar1 »
"C'est pas une restauration, c'est une rénovation."--François Martin.

Alex G. Bell

  • Guest
Re: Western Electric 2EB dial
« Reply #11 on: May 22, 2017, 04:19:39 PM »
Here is another 2A > 4H conversion. This one has the W to the left of Y, as on a 5H dial.  It also has "Twin Contacts" (bifurcated W/BB contact springs), as on a 5H-type dial. However, the contact springs are NOT exactly the same as those on a 5H! (Notice the 2 offsets on the lowest spring.)

Note the holes on the dial case where the external finger stop of the 2A was replaced with an internal finger stop, so that the dial could be mounted on a D1 handset mounting (202) or H1 tel set mtg. (302), both of which have recessed dials:

http://www.ebay.com/itm/1938-4H-Western-Electric-telephone-dial-phone-part-/332230333983

I have been told that it was necessary to enlarge the hole below the terminal strip -- at least for those with the W on the left side -- when installing these later type bifurcated contact springs on  a 2A (or 4H??)...does anyone know if this is true?
Very interesting photos!  I don't recall seeing (but might have failed to notice) a mix of bifurcated BB-W springs and single point contacts on the Y-BK-RR loop contact circuit.  It certainly makes sense in the short run since contact problems are much more likely in a dry receiver circuit than the loop circuit with DC through it.

Seems like you could remove the contact sets off a 2AB and one converted to 4H and compare the hole sizes you asked about and then put them back without changing M/B ratio adjustment.  IIRC, the contact spring sets are mounted with FH countersunk screws which should re-center the spring sets back to their original locations relative to the dial body.