The name of the engineer and the location is unknown, but this photo was probably taken at 111 Sutter Street in the mid to late 1930's, judging from the equipment in use.

The "VU" meter has obviously been added to the microphone mixer, meaning it dates to an earlier era. Also, the knobs below each fader are labelled "microphone current", indicating they were designed to be used with carbon microphones, which required an external voltage source. Carbon microphones ceased to be used in the mid 1930's when ribbon microphones such as the RCA 44A (at left) became available.

The engineer is mixing a remote broadcast, as evidenced by the labels over the mixers, which indicate "Mission Dolores", "Studio Announcer", and "Opera House".