Astatic Model D104 Microphone
Introduced in 1933, the Astatic model D-104 became known for its high frequency response that contributed to better communications audio quality. Early D-104 mikes used a 1" thick case, a large ID tag, and holes for "ring & spring" mounts. The design was modified in April 1937 with smaller tags and reduced thickness. A black "grip" switch stand ("G" Stand) with a metal ID tag was manufactured in January 1938. A solid-state amplifier was incorporated into the "G" stand in the 1960s.