ONLY EIGHT CIRCUITS

Radio Record, Volume I, Issue 15, 28 October 1927, Page 3

ONLY EIGHT CIRCUITS

Not infrequently one hears people in New Zealand state that as new circuits are being brought out they will wait and get the latest. The Sydney "Wireless Weekly" says: "There are just cight basic circuits in radio reception, and this despite the hundreds upon hundreds of so-called circuits. In -fact, nothing serves to confuse the layman so much as the weekly appearance of new circuits with high-scunding names and lavish claims, producing the general but erroneous impression that radio is a constant experiment with receiving sets rendered obsolete a week after they are purchased. ‘The plain truth is that new circuits are very, very rare, although new names are plentiful. Present Basic Circuits, Our present-day basic circuits are as follow :- 1. The simple vacuum tube receiver, a most elementary tuner. _* 2. Lhe simple cauum tube receiver, with a most elementary tuner, and no provision for so-called regeneration or radio-frequency amplification. 3, The regenerative receiver, in which part of the output from the detector is returned to the detector to increase the strength of signals. 4, Audio-frequency amplification, used in conjunction with all kinds of re--ceivers in order to increase the sound volume in ’phones or loudspeaker. 5. Tuned radio-frequency amplification, in which each stage is tuned so as to secure the utmost transfer of radio energy from one stage to the next. 6. Untuned radio-frequency amplification, utilising fixed transformers which require no tuning or adjustment. 7. The reflexing arrangement, whiereby a set of tubes do double duty, first as radio-frequency amplifier and then as audio-frequency amplifier, 8. The super-heterodyne, whereby the incoming wave is thrown into interference with a locally generated frequency, setting up a so-called intermediate frequency current which is ainplified and then detected,