Text: A device used in radio transmission and in laboratory work, for the purpose of eliminating undesired frequencies (wavelengths). Essentially such a device is a filter- (q.v.) so arranged as to suppress or eliminate certain frequencies or harmonics (q.v.). In radio broadcasting it is particularly essential that all undesired frequencies or harmonics be suppressed. Basically the system involves a special coil shunted by a condenser and tuned to the frequency of the interfering wave, the main tuning circuit at the same time being adjusted to the desired frequency.

See Also:

Source: 190