1927-1930 Western Electric model 102

Detail:

The Model 102 telephone (B1 mount/set) was Western Electric's first widely distributed telephone set to feature the transmitter and receiver in a common handset. Prior models had been of the "candlestick" type, which featured a transmitter fixed to the base, and a receiver held to the ear. The 102 was manufactured between 1927 and 1929.

As early as 1890, Western Electric had been experimenting with single handset models, but two technical problems prevented them from being widely produced at that time. First, the transmitters of the day did not work well unless oriented in a vertical plane. If moved to other angles, as would be expected in a single handset, carbon granules in the transmitter would move around, resulting in poor voice quality, referred to as "carbon noise".