Similar transmitters went to WBAY and WEAF in 1922. In May of 1923 news was released of the 101A series (System Code), 1-A transmitter (Transmitter Code) with a power rating of 500 watts. 

Quite a few of these transmitters were sold to early broadcast companies primarily due to two reasons (1) it was the first 'real' broadcast equipment that was available which offered fairly adequate performance and (2) due to the pressure of the AT&T company who threatened to sue all broadcasters who did not use their transmission equipment. This was part of their territorial rights as agreed to under the incorporation of the RCA. 

The list also showed a 102A (System Code) and a 2A (Transmitter code); this was a 100 watt unit that came out about the middle of 1923 and had five 211 tubes. The smaller 103A (System Code) 3C (Transmitter code) was for a 50 watt unit that came out in early 1924 and used two of the 211 type tubes. All of these systems used the 'constant current' modulation scheme (Heising modulation, 'plate current')

Later additions to the WE lineup were the 105B (System Code) 5C (Transmitter code) with a power of 5 kW and manufactured about early 1928, this unit had two 220 tubes and it used the 500 watt transmitter as the low level driver. This principle of low level modulation and driving became a classic hallmark of all WE high power transmitters in future years.

The 106B (System Code) 6B (Transmitter code) came out in mid 1928 was a 1 kW transmitter using one 228 tube. There was also the 107A (System Code) and 7A (Transmitter code) which was the first of many 50 kW units. This came to birth in early 1928 and consisted of six type 232 tubes.

This second set of transmitters was, as it were, a "2nd generation" system which offered higher power, stability; improved frequency response and reduction in audio and rf-distortion products. It was during the early development period that low level modulation was developed for trans-Atlantic telephonic transmissions and the incorporation of crystal frequency control developed at WEAF and WBAY that allowed this second generation series to offer superior performance and thus it placed aural broadcasting into a professional light.

During the middle 1930's there came to be developed the 300 series line of broadcast transmitters by the Western Electric Company. Like all of the one-hundred range numbers, the number 300 indicated a series. The letters A or B, or even later additions served only as revision level changes to this series or family of equipment. The building block of the 300 series was the model 23A transmitter.

They were of the second generation of broadcast products by Western Electric. Economy was the hallmark of this generation of transmitters; intended primarily for the small stations, there were two models produced. 310A was a 100 watt unit and the 310B was the 100 watt unit with additional final tubes to produce 250 watts. These transmitters served small stations and night time powers for many, many years.