| Year | 1920 |
| Date | 18-Mar |
| Volume | 42 |
| Issue | 986 |
| Page | 278 |
| Category | Electronic |
| Part | 5 |
| Title | Wireless Notes |
| Author | A.V.Ballhatchet |
| Notes | Sectional diagram (theoretical) of telephone receiver, step down transformer for wireless work, compound ring type magnet & simple semi-circular magnet |