| 摘要 |
1359233 Wired television BLAUPUNKTWERKE GmbH 23 Nov 1971 [24 Nov 1970] 54343/71 Heading H4R In a common antenna receiving system in which a plurality of channels in band III and a channel lying outside band III are made available to a plurality of receivers via a common output line, a frequency-converter is provided for transposing the channel lying outside band III into band III, the local oscillator frequency of the frequency-converter being such that when a receiver in the system is timed to a channel in the lower frequency range of band III the frequency of the local oscillator of said receiver is located between the frequency of the video carrier of said transposed channel and the frequency of the audio carrier of the next channel below it in band III. By this means additional channels may be utilized in band III without mutual interference. |
