One of the most recognized images of early radio broadcasting was the ring-mount carbon microphone. The microphone element itself was suspended by springs to isolate it from noise and vibration. Carbon microphones had limited frequency response and had an inherent hiss, but they had high output levels and were low impedance devices. This meant that they did not require additional amplification, and did not need extensive shielding to prevent hum pickup.This microphone was included as part of a mid-1930's portable public address system. It is Universal type XX 8593. It is mounted in the original table base of unknown make. Very good original condition. 7 7/8" x 5 1/8".~~ DEAR BIDDERS, Please View More Detailed Close-Up Images by visiting our website - Sofedesignauctions.com ~ Thank you ! ~~~~~~. Detailed condition reports are not included in this catalog. For additional information, including condition reports, please contact us at info@sofedesignauctions.com