A New Receiver

Radio Record, Volume III, Issue 24, 27 December 1929, Page 31

A New Receiver

Recent American Inuention eee ‘A NEW type of radio receiver which combines a specially designed valve’ with a radically different electrical ¢ir- " euit was, demonstrated recently in America. The unique part of the device is that it avoids most of the engineering practices and methods of con- _ struction and operation upon which other present-day receivers depend for their operation. _ Part of the instrument employs six vives of the 199 type. The audioauxplifier unit has two valves of the new type developed by the inventor. Before the radio frequency amplifier, ‘which employs no tuning circuit to ad- ". just the receiver to the desiréd wave- .. length, is placed: a special "filter cir‘cuit’ to exclude all the broadcast energy except that of the station desired In enumerating these departures : from current radio designs, the inven- ‘ tor stated that his valves, instead of employing negative "C," voltages employ a method of biasing by means of ‘a positive voltage or battery. This _ method, he explained, combined with the new circuit, affords very largé sig-. nal gains, or amplification. All of the valves are of the three-element type. using internal parts known to the radio -vorld as "grid," "plate," and "filaMent." However, the élements are said _to function in a quite different way from the ordinary internal parts of a standard radio valve, . The receiver functions as an implifier over a very wide band of frequencies, without distortion, and the only frequency limiting device in the entire set.is the band selector ahead of the radio amplifier and a transformer coupling device which links the set to the "loudspeaker. Thus the set would be applicable to radio-vision reception, as Well as for broadcast programmes. A majority of the radiovision test programmes are béing broadcast in channels. 100 wide, whereas the broadcasts of audible programmes are transmitted in channe s only ten kilocycles in width. —