| Year | 1922 |
| Date | 12-Jan |
| Volume | 46 |
| Issue | 1,081 |
| Page | 44 |
| Category | Radio Engineering |
| Part | 2 |
| Title | The Theory of the Thermionic Triode |
| Author | Captain H. de A.Donisthorpe |
| Notes | Simple valve circuit, characteristic curve, assembly of small condenser, combined grid leak and condenser |