As a long-time collector of early microphones, I’ve always been intrigued by this image. It shows the microphone storage room at NBC in New York in 1929. Operating engineer George McElrath is checking out the microphones that will be used for the live broadcast of President Herber Hoover’s inaugural. The one-hour broadcast required hundreds of hours of advance preparation. No recordings were allowed at NBC during these years, which meant that all audio originated from microphones. That fact would have made this an important and frequently used room in the RCA broadcast center at 711 Fifth Ave. In the years before the development of the ribbon and dynamic microphone technologies, the only useful options were carbon or condenser microphones. Both systems required external DC power, typically provided by batteries. While offering better fidelity, condenser microphones were too fragile to be used outside the studio. So, the older carbon microphone technology was typically used for remote broadcasts. In this storage room, we see dozens of Western Electric 600-A double button carbon microphones stored in the wooden box labeled “Mikes.” McElrath is mounting them with suspension springs in both floor stands and the ubiquitous 1-B desktop enclosures. The parts storage boxes on the shelves behind him are artfully labeled as “Rheostats and Potentiometers,” “Sockets,” “Signal Lights,” “Screws,” “Washers,” “Mike Fittings” and various other categories. The original print of this early NBC publicity photo comes from the collection of Bill Newbrough. John Schneider is a lifelong radio history researcher. Write him at firstname.lastname@example.org. This is one in a series of photo features from his collection. See past images under Columns/Roots of Radio at radioworld.com.