What was the Shure SW-109? Was it a microphone?
The SW-109 was a switch used on the Shure T-17 battle annouce microphone, widely employed during World War II.
The SW-109 switch was black. Emblazoned on the switch in white was: SW-109...SHURE...and the Shure logo. Most users thought the mic model number was SW-109 because of the prominent white lettering.