Customer-owned wood phones converted at WE Repair Shop

[poplar1]

Western Electric sometimes "modified" customer-owned telephones. There was a one-time charge for materials and labor, then a monthly lease charge on the installed parts. The modification made the phone roughly equivalent to a 500 set. The following parts were usually added, but could vary.

425-type network
C4A ringer
Dial
New 143-type hook switch
T-1 transmitter unit
Receiver unit
Receiver cord

Dials were usually mounted inside the phone, but occasionally outside. Some did not have a dial.

http://www.ebay.com/itm/121288549970
(Disregard seller's info about 1945 conversion and removal from service in 1960; the ringer is dated 1966.)

[poplar1]

As the diagram shows, when the original 3-leaf hook switch was retained, the contact springs were rearranged so that when the receiver was on the hook, the phone itself was shorted out. This ensured that there was no way to "eavesdrop" with the hook down.

[poplar1]

Another Kellogg--they used a 685A subset without the cover and added a dial mounting.

[poplar1]

This one modified by the WE shop in Minnesota

[poplar1]

Normally, the original ringer if present was left connected to the original ringer, but neither was connected to the line. So you could still turn the crank to make the original bells ring. For incoming calls, the C4A ringer (as in a 500) was used. This one was offered by an Indiana Ebay seller.

[BDM]

This is fascinating. I never knew this nor would have guessed. I would probably have written off the phone as modified by a small ma/pa TC or on someones work bench.