| Year | 1920 |
| Date | 10-Jun |
| Volume | 42 |
| Issue | 998 |
| Page | 536 |
| Category | Electronic |
| Part | 3 |
| Title | The Action of the Wireless Telephone |
| Author | R.A.Mallet |
| Notes | Diagram of sound wave drawn from an oscillogram, high-frequent & the audio-frequent wave diagrams, diagram of the combined waves, microphone in simple circuit controlling amplitude of emitted wave, improved circuit with the microphone coupled to aerial, circuit devised by E.H.Colpitts in 1914 in which one valve performs two functions, alternative circuit combining several advantageous features |