Coaxial Cable Network Research Articles

Residual attenuation equalisation of broadband systems by generalised transversal networks

Residual attenuation equalisation of broadband coaxial-cable systems has been achieved elsewhere by a set of harmonic cosine characteristics based on an almost linear frequency scale. This method is, however, not efficient for systems which exhibit high distortion near the bandedges. A simple analysis of measured characteristics yields the requirements for suitably transforming, or `warping?, the frequency scale. Generalisations of the transversal-equaliser principle offer the realisation of cosine characteristics with frequency scales which match particular problems. The investigation on which the paper is based was concerned with the coaxial-cable network of the British Post Office, and led to novel designs, of which the `twin cosine equaliser? has been accepted for service use. This device enables residual distortion of up to 6dB to be reduced to rather less than 1dB, with a minimum of auxiliary instrumentation.

Coaxial-Cable Networks

This paper discusses the general features of the coaxial system, its application for both telephone and television, and the future prospects for very-broad-band transmission facilities in the communication network.

Frequency Division Techniques for a Coaxial Cable Network

A description is given of developments employing frequency division techniques by which the telephone-message-carrying potentialities of the coaxial cable system are realized. By these methods 480 high quality telephone messages are prepared for transmission over the line and restored to original condition at main terminal points. At intermediate points appropriate groups of channels may be removed, inserted, bridged, or relocated in the frequency spectrum of the line.