Bishnu S. Atal
Julius Andrae

Harold D. Arnold

First Bell Labs research director
From Wikipedia

Harold DeForest Arnold (September 3, 1883 – July 10, 1933) was an electronics engineer and pioneer of radio communication and telephony. He served as the first director of research at Bell Telephone Laboratories from 1925 to his death.

Arnold was born in Woodstock, Connecticut, to Calvin Arnold and Audra Allen. He studied at Wesleyan University for his BS and MS and then studied physics at the University of Chicago for his PhD. He initially studied under Albert A. Michelson but when he confided to Robert Andrews Millikan that he would probably have to commit suicide as he could not meet… More on Wikipedia →

Timeline events (1)

Arnold perfects the vacuum-tube telephone amplifier

Related concepts (2)

Audion
The Audion is an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest as a diode in 1906. Improved, it was patented as th…
Vacuum tube
A vacuum tube, electron tube, thermionic valve, or tube is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential…