Six circle super

from Wikipedia, the free encyclopedia

The term six-circle super is colloquially for a radio receiver , usually implemented as a tube receiver , which has six resonant circuits for transmitter tuning , with the help of which the desired reception frequency is   filtered out of the amplified antenna signal .

The number of oscillating circuits in connection with the number of tube amplifier stages is a rough measure of the quality of the receiver. This information was previously used in marketing as a selling point for the general public.

While simple so-called straight - ahead receivers only have one or sometimes two tuned oscillating circuits, which are fundamentally limited in their reception performance and quality, the number of effective oscillating circuits used as filter elements can be considerably higher with " superheterodyne " or superimposed receivers .

Functionality and application

With the "Super", the set receiving frequency is mixed with the help of an adjustable oscillator frequency generated in the receiver itself so that (simplified) a difference frequency (so-called " intermediate frequency " IF) is created which is always the same regardless of the transmitter setting and which in turn is several Can go through resonant circuits and amplifier stages. The useful signal for sound reproduction is then obtained from this amplified IF.

The advantage over the straight-ahead receiver is, in addition to the better frequency selection, that the filter properties can be designed in such a way that the sound quality of the loudspeaker reproduction is also significantly improved. These additional IF filters are permanently set in the manufacturer's factory and therefore unalterably optimally set.

The correct setting of a simple straight-ahead receiver requires a lot of skill and experience on the part of the user, while a Super is easy to use. Straight-ahead receiver, e.g. B. singles of the " Volksempfänger " type were no longer state of the art in the 1940s, but the post-war hardship allowed them to survive as a cheap radio in Germany until the mid-1950s.

In the course of receiver development since the mid-1930s, the number of six matched circles (in conjunction with three composite tubes) has proven to be the optimal compromise for standard home devices in terms of effort and benefit for the amplitude-modulated wave ranges ('short-medium-long wave'). They enabled safe reception without major antenna effort with a gain reserve that allowed automatic control in the event of poor reception (“ loss compensation ”).

Receivers with more than six tuned oscillating circuits were designed in the upper price segment as luxury devices for remote reception or for special purposes in the commercial and military sectors. Even car radios often had more than six circles due to the difficult and strongly changing reception conditions with a short antenna.

The “four-circle” type is known as the downward deviation. In the post-war years, some German device types did not have an amplifier tube with two filter circuits. This meant a restriction in the reception performance, lower sound quality and no loss compensation, but the ease of use of the Super was retained. These devices were material-saving and cheaper, but were no longer available from the mid-1950s.

The six-circle super was the standard for tube sets until the end of the 1960s, and the first transistor radios were also designed to be analog in terms of their circuitry, even if the electrical properties of the semiconductors often required major modifications.

literature

  • Martin Gerhard Wegener: Modern radio reception technology. Franzis, Munich 1985, ISBN 3-7723-7911-7 .
  • Ferdinand Jacobs: Course in radio technology. Franzis, Munich 1951, ISBN 3-7723-5362-2 (2 volumes).