Arcturus 122 (UY)
AC Amplifier Tetrode
1929

The 122 (UY) was released in April of 1929 and was essentially the same as the RCA 224. By July of 1929 Arcturus had changed the number to 124, in keeping with the rest of the industry. See the listing of the 122 (UX) for the other Arcturus tube marked 122.