| Year | 1920 |
| Date | 21-Oct |
| Volume | 43 |
| Issue | 1,017 |
| Page | 323 |
| Category | Electronic |
| Part | 9 |
| Title | Wireless Notes |
| Author | A.V.Ballhatchet |
| Notes | Some Valve Circuits. Reaction coils or reactances (wooden, moulded ebonite), a grid condenser, a grid leak, transformers, detector-relay, dry cells, tuner extension when using crystal detector, hard valve, high-tension current, weak signals |