| Year | 1921 |
| Date | 03-Feb |
| Volume | 44 |
| Issue | 1,032 |
| Page | 89 |
| Category | Electronic |
| Part | 10 |
| Title | Wireless Notes |
| Author | A.V.Ballhatchet |
| Notes | A Wavemeter. The inductance, the switch, the condenser, wiring diagram, the change-over switch, the detector, the buzzer, uses of a wavemeter |