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From the December 2002 Singing Wires Journal newsletter

The A-B-C's of Western Electric Desksets

What the number and letter designations on early Western Electric desk sets mean

by Gary Goff with subset technical data provided by Steph Kerman

Do you know your ABC's? I suspect you do, but there is one set of letters that apparently is not well-known to telephone collectors and those are the letters that identify the various and sundry early desksets that came after the candlesticks or deskstands, as they were known.

Numbers and or letters have always been used by Western Electric or the Bell System to identify phones. There's the early #10, 20B and 20AL sticks as well as the 50AL and 151AL dial sticks. So it's no surprise that the very first type deskset made by Western Electric, which looks a little like a cutoff candlestick with a handset was known as the D76869 and later renamed the "A1" when issued for the first time to the public.

The round base A1 mentioned above began life as a prototype phone (Pat. Date 1922) which was given a design number until it was renamed with an "A1" stamped on the back of the neck. This phone, which looked like a candlestick cutoff, was in fact not a cutoff but a new design and was called a D76869 phone until issued to the public in or around 1925. These early pre-public sets were used within the Bell System central offices and no doubt in their business offices as well. It is believed that a candlestick type #2 dial was modified for use with these new desksets.

Sometime around 1926-27, the Bell System issued an entirely new round base deskset patterned after the A1, called the B1. It is most correct to call this deskset a "B Handset Mounting." It was a base, cradle switch, and maybe a dial. The correct dial for this phone, which was initially issued with it, was the #2HB, which was specially designed for use with a handset. The dial mounted on the surface of the base just as the dial on the earlier A1 handset mounting.

In 1928 or thereabouts, the Bell System issued a new deskset with an elliptical base, an inset dial, and the now familiar E1 handset. This set required an entirely new dial, the #4, which had an internally mounted fingerstop, which permitted the dial to be mounted in the inset hole in the base. This set was known as the "D Handset Mounting." It should be noted here that all these desksets to date required the use of a separate subset where the "network" and bells were resident. This was generally mounted on a wall or side of a desk. In later years, the more modern and efficient F1 handset was installed on the phones in the field or added when refurbished for reissue, before and after the release of the "H Handset Mounting." In 1950, the Bell System reissued "D Handset Mountings" as colored desksets like the Imperial or in a range of colors depending on the needs and desires of the customer. There was of course a charge for these special sets.

At or around this same time, the company issued a wall set that operated in the same manner as the "B" and the "D"set, appropriately named the "C Handset Mounting." This set was generally hardwired to the subset as it too contained nothing more than a hookswitch and a dial mounted on a special pedestal.

Later models were the "E" series of business desksets complete with buttons for multiple line pickup, hold feature, an intercom circuit, and signaling key. These sets required an equipment cabinet which contained line and hold relays, light relays for illuminating small wall placed light boxes to signal which lines were in use to those working in the vicinity, and an intercom circuit.

I am not aware of an "F Handset Mounting."

The "G Handset Mounting" was the modernized "C" wall set and was issued with either the E1 or F1 handset or in later years a G-type handset. It too required a separate subset to which it was generally hardwired.

And finally, for this article, the introduction of the "H Handset Mounting" in 1937, most often referred to by everyone today as the 302. This was the first Bell System deskset to be a complete phone containing in addition to switch, dial, etc., the network and ringer. These sets were generally marked on the bottom or on the back inside edge of the housing with an orange "H" and a number which further designated the modifications to the deskset. The common private line model was the H1 and the party line model was most often marked H3.

All of the desksets described in this article could have more than one model and one will often see a "D1" or a "D2" or even a "D5." These numerical designations identified the internal wiring and switch pileup designs which accommodated other features over and above the standard residential deskset.

Now that we have provided some basic information about the deskset itself, it's important to provide a short review of the type of subsets used with these "handset mountings." To clarify, a handset mounting consists of the base shell, switchhook assembly, and bottom cover without handset, dial, or cords. A "102" is a complete sidetone-type hand telephone set which may be assembled from a "B" or "D" handset mounting equipped with an E1 or F1 handset, dial or dial blank, and a 3 conductor mounting cord. A "202" sete is a complete antisidetone hand telephone set which may be assembled from a "B" or "D" handset mounting equipped with an E1 or F1 handset, dial or dial blank, and the 4 conductor mounting cord required for antisidetone circuit operation.

To summarize, the "102" and "202," which are model numbers of complete hand telephone sets not including the subset, do not indicate whether a "B" or "D" handset mounting is included. Early 102's were produced with "B" handset mountings and later 102"s with "D's." Production then continued using "D's" to build 202's. "B's" and early "D's" were converted from 102's to 202's by replacing the 3 conductor mounting cords with 4 conductor ones.

Since a "C" handset mounting uses no mounting cord per se, the proper model number for a complete hand telephone set including the handset and optional dial can be either 101 or 102; either is correct since the only difference would be the mounting cord which is not provided on a stationary mounted telephone set like this.

Matching subsets (ringer boxes): 534 and 584 are sidetone subsets. There are also 584 type extension ringers not containing any speech circuit. They are not suitable for use with a talking set unless an induction coil and capacitor are added. 634 and 684 are antisidetone subsets.

You may be interested in the following if proper transmission and reception quality is your goal:

A 634A or BA or 684A or BA antisidetone subset requires the use of a 202 antisidetone hand telephone set, OR a 120AL, 140AL, or 151AL deskstand.

A sidetone 102 hand telephone set or sidetone 20AL, 40AL, 50AL or 51AL deskstand must be used with a sidetone 534A or 584A subset. A sidetone 102 can be converted to an antisidetone 202 by replacing the mounting cord with one that has 4 conductors. This will provide a worthwhile improvement in performance. But the switchhook contacts in a sidetone candlestick are insufficient to permit conversion to antisidetone operation by replacing the cord.

An antisidetone 202 type hand telephone set or antisidetone 120AL, 140AL, or 151AL deskstand can be used with a sidetone subset by insulating the BK mounting cord lead but the performance will be identical to that of a sidetone set.

If additional technical subset information is desired, there are two Bell System Practices (BSP's) that are worth reviewing. The first, Sidetone Section C31.101, Issue 1, dated 2-15-33 and the second, Antisidetone Section C31.111, Issue 1, dated 6-1-31. Each of these addresses as many as 7 or 8 sets of each type.