SHORT WAVE

Radio Record, Volume I, Issue 4, 12 August 1927, Page 5

SHORT WAVE

RECEPTION

NOW. POSSIBLE TO ALL

_ WONDERFUL NEW DEVICH. Until recently reception of short wave broadcast programmes was confined to amateurs and experimenters who could build their own short-wave equipment for the purpose. Now, through the invention of W. M. Bruce, Jnr., consulting engineer of the Crosley Radio Corporation, Cincinnati (U.S.A.), and expert on submarine cable, the field has been widened so all radio fans who can afford the cost may use their ordinary receiving sets and enjoy the new form of entertainment, Short Wave Feats. Short wave programmes, incidentally, | already are being broadcast by KDKA, Pittsburgh; WGY, Schenectady; and WLW, the Crosley radio station at Cincinnati. Remarkable records have_ been achieved in receiving short wave broadcasts. Stations of but a few watts power have been picked up thousands of miles away. The New Device. The history of Mr. Bruce’s new device, known as the "Iowave," is extremely simple. The unit consists essentially of a sinmal] short-wave receiving set with detector and one stage of audio frequency amplification and an oscillator tube adjusted to operate within the broadcasting range. Short to Ordinary Waves, Signals are received by the shortwave set and are detected and amplified by the two valves provided for this purpose. ‘The amplified signals are then impressed on the oscillator valve, which ig modulated by them and which

reproduces the signals on a longer wavelength, for example, 800 metres, so that they can be heard on an ordinary broadcast receiving set attached to the device. It is merely necessary, then, to connect the output of this os cillator valve to a radio set, tune the set to 300 metres (or whatever wavelength the oscillator valve is adjusted to), and listen to the short-wave signals. Iu brief, the signals are picked up on the short wave, used to modulate an oscillator valve, and rebroadcast inte the radio set at ordinary broadcast wavelengths. Simple, But Ingenious. Simple as the unit is in theory, ingenuity of design has been used by the inventor in order to reproduce units iv large quantities which would have uniform characteristics. ‘The small capacities and inductances which must necessarily be used in the short wave portion of the circuit make it important that precision methods be used in its design and manufacture. As produced by factory methods, the new invention is hoth compact and rugged. ‘Lhe cabinet ie about one-third the size of an ordinary five-tube radio set. Connects to Ordinary Set.

To install the Lowave, the aerial lead wire is disconnected from the radio set and attached to the aerial terminal of the Lowave. ‘The terminal on the Lowave marked "Set" is then connected to the aerial post of the radio set. The "A" plus and ‘‘A"? minus terminals ef the Lowave are connected to the regular "A" battery used with the radio set, while the "B" battery terminals of the unit are counected to a separate "B" battery. Easy Operation, Short wave tuning is accomplished by means of a control knob and a second dial adjusts the amount of regeneration of the short-wave detector valve In order to shift from short-wave reception to long wave reception, or vice versa, a push pull switch is provided. When this switch is pushed in, the antenna is connected direct to the antenna post of the radio set, cutting the Lowave out of the circuit. When the switch is pulled. out, the incoming signals pass through the Lowave_circuit before reaching the switch without disturbing the connections, in order to shift back and forth from short waves to ordinary broadcast wavelengths.