| Year | 1930 |
| Date | 16-Jan |
| Volume | 62 |
| Issue | 1,497 |
| Page | 63 |
| Category | Electronic |
| Part | 2 |
| Title | The Selectivity of Wireless Receivers |
| Author | W.Greenwood |
| Notes | Practical Methods of Improving Selectivity. Circuits with inductance, resistance and capacity in series, two tuned circuits arranged to provide selectivity, diagram of capacity coupling |