"The phone is a remarkably complex, simple device, and very rarely ever needs repairs, once you fix them." - Dan/Panther
Started by waynet7, May 20, 2017, 09:19:07 AM
Quote from: unbeldi on May 20, 2017, 11:04:40 AMFunctionally, 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.
Quote from: Alex G. Bell on May 20, 2017, 03:07:30 PMHowever the contact set could be swapped with one from a 5H dial, effectively converting the 2E to a 2H without making a permanent modification.
Quote from: unbeldi on May 20, 2017, 03:36:51 PMWell, 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.
Quote from: Alex G. Bell on May 22, 2017, 02:27:39 PMHave 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.
Quote from: poplar1 on May 22, 2017, 04:03:43 PMHere 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-/332230333983I 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?