TIPS AND JOTTINGS

Radio Record, Volume I, Issue 44, 18 May 1928, Page 13

TIPS AND JOTTINGS

Interfercnee by Trams. XNPERIMENTS to overcome this kind of trouble have been undertaken in England and in Europe, in co-operation with the tramway and broadcasting authorities, and it is said that the results have been most encouraging, though particulars are not yet forthcoming. DOUBLE IMPEDANCE. 'PHOSIE constructors who are experi. menting with double impedance are recommended to commence with a coupling condenser of a half mircrofarad, which is the value that is likely to be quite satisfactory. Itxperiment shows that capacities up to one microfarad may be used with good effect, but the half i» a good average, and yields very satisfactory tone. It is quite feasible to run three stages of double impedance, but they should all be of high quality, and the best method of construction would be to perfect one stage before adding another. MARCONI VALVES. AbtHOU GH Marconi receiving valves have been widely used in other countries for a considerable time, the first shipment has only recently reached New Zealand. Several different types are i10w available at average priccs, . "Pirates" in Canada. N Canada a motor-car round-up of pirates has been quietly proceeding for several months. In some cases the Royal Canadian Mounted Police have proved helpful in tracking offenders. |