Figure 7-4.--Schematic diagram of a carbon microphone.
Kapsel
File:Carbon amplifier radio receiver 1919.png - 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
Carbon Mic Replacement To Magnetic Mike Converter Circuit under Repository- circuits -41507- : Next.gr
Use An Old Phone Handset To Produce A Lo-Fi Mic | Production Expert