Improving Selectivity

Radio Record, Volume V, Issue 14, 16 October 1931, Page 29

Improving Selectivity

A Suggestion A WELLINGTON experimenter called in at the office the other day und made some suggestions concerning the separating of 2YA and 27ZW. His plan, he contends, has worked in several localities, and with the very humblest of apparatus, ineluding an ordinary crystal set. Although necessitating letting down the aerial he says the results are really worth while. The aerial consists of a double wire, the two wires being separated by four to six feet with insulating spreaders

which muy be made of seasoned wood. The two wires are joined at the end most distunt from the set, and two leads in are brought down to two formodensers. The other terminals of these formodensers are connected and a common lead is taken to the aerial terminal of the set. It is advisable to have «a separate primary, as is shown in the theoretical sketch. The formodensers are adjusted until the

stations can be separated cleanly. Once adjusted the device needs no further attention. In all, from 80 to 100 feet of actual aerial wire is used, although it might be more than this when the leads in are taken into consideration. This means that the poles should be about forty feet distant.