Pupin loading coils
Bobinas de carga de Pupin
- Date
- 1899-1900 · confidence medium
- Place
- Columbia University, New York, United States
- Credited to
- Mihajlo Pupin (Serbian-American) and George Campbell
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
Inductors placed at regular intervals along telephone cables to correct the distortion and attenuation that grow with distance. They allowed cable conversations over several hundred kilometres without amplifiers.
Heaviside proposed the idea in 1881; George Campbell of AT&T reached the same solution independently, and the company bought both patents. Pupin was born in Idvor (Serbia) and did his work in the United States.
What it led to
- long-distance telephony by cable in the first decades of the 20th century
- transmission theory of loaded lines
- an alternative to electrical amplification until the vacuum tube (1915)