Partial Suppression of One Side Band in Television Reception

An experimental and theoretical study was made for the purpose of determining the advisability of operating a television system with the carrier located near one edge of the over-all selectivity curve. Satisfactory results were obtained when operating a television system with the carrier at one edge of the over-all selectivity characteristic. Fidelity and phase characteristics were experimentally determined with the carrier located at the center and near one edge of the selectivity curve. Fidelity and delay characteristics were also calculated for various carrier locations on the selectivity curve. Although calculations show that for large percentages of modulation and with the carrier detuned, any detector will reproduce not only the original modulation frequencies but also various combination frequencies, observations on picture quality indicated that the distortion due to linear detection produces no noticeable detrimental effects on the picture quality. The fact that fewer stages of amplification are necessary in the intermediate-frequency amplifier of the receiver when the carrier is tuned to one edge of the intermediate-frequency selectivity curve makes it very desirable to adopt this system.