File:CBS microphone, 1930s, used by Franklin Roosevelt for his Fireside Chat radio programs - National Museum of American History - DSC06235.JPG - Wikimedia Commons
Marconi-Reisz Carbon Microphone (circa 1930) Just the job for a Kings Speech or two! Also very popular with other personalities of 1930's European showbiz! | Martin Mitchell's Microphones
Myrtle — Ear Trumpet Labs
How to get that Vintage Mono Sound. A 1930's Microphone Shoot-out! | Martin Mitchell's Microphones
Microphone, CHNC Radio Station - 1930s | 100objects
Ear Trumpet Labs - Myrtle Mikrofon | martinsmusikkiste Martin Hense