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Transmitter introduction

Page history last edited by David Samways 5 years, 7 months ago

 

 

 

 

Extract from the 1964 Marconi Catalogue

 

The long experience of the Marconi Company in the production of television transmitters stems from the design and manufacture of transmitting equipment used by the BBC for the first public television service in the world, set up in Great Britain in 1936.  Present-day designs achieve a high standard of technical performance, with a maximum degree of simplicity and a minimum number of valves.  The range of transmitters contains many units which are common to several designs, resulting in advantage from the points of view of both operation and spares holding.  The emphasis on simplicity and reliability in design is of vital importance as television spreads more widely throughout the world.  Because highly reliable equipment is available stations can function with a smaller number of highly skilled operational maintenance personnel.

 

In association with its subsidiary, Marconi Italiana S.p.a., the Marconi Company now extends its range into the UHF band to cater for future television expansion.

 

A feature of the Marconi range of designs is the provision of facilities for operating transmitters in parallel.  This is of particular importance in television where the slightest technical defect in the transmitted signal is immediately noticeable.  With paralleled transmitters, the defective transmitter can be withdrawn from service without interrupting the transmission and therefore maintenance problems are very much reduced.

 

This method of operating is very much advantageous when the transmitters are unattended or under remote control.  All transmitters in the current range are designed for this purpose and may be used with various remote controlled systems.  Stations of this type are already in operation.

 

The provision of high-quality service to areas poorly served by the main transmitter is of increasing importance as the television service spreads.  This can be provided by means of low-power television translators, serving small areas in which coverage cannot easily be provided by other means.  These translators are designed for unattended operation and can be remotely controlled.  The equipment is suitable for operation at a variety of standards and vision / sound power ratios.

 

 

Extract from the 1980 Marconi Catalogue

 

Marconi has been designing and manufacturing broadcast transmitters for nearly 60 years. It is one of the very few companies who still produce transmitters for all broadcasting applications covering long, medium and short waves, Television Bands I, III, IV and V, and FM Band II.

 

Our staff consists of long service members reinforced by young and active newcomers, so new ideas and techniques are put into practice tempered by experience. This combination provides equipment of modern design and high reliability incorporating many major innovations.

 

Marconi built the transmitter for the world's first television service in 1936.  Since then it has taken part in all the major advances as television expanded into Band III and then into Bands IV and V.  It was largely responsible for the transmitting equipment of the BBC and IBA for colour service and its transmitters have been particulary successful in the export market.  The Company is now introducing the fifth generation of television transmitters with a new range of VHF and UHF equipment featuring compact design with great relibaility. 

 

A major customer for these new UHF transmitters is the Independent Broadcasting Authority who has recently purchased fifty equipments.

 

 

Frequency allocation

 

 

Band 

 

  Frequency range  Channel spacing  Product details 
Band I  VHF  47 to 88MHz  6, 7 or 8MHz depending on the country

 

here 

Band III  VHF  174 to 230MHz  6, 7 or 8MHz depending on the country 
Band IV  UHF  470 to 614MHz * 8MHz 

 

here 

 
Band V  UHF  614 to 854MHz * 8MHz 
         
Products common to more than one band:   here 

 

*  There were differing views on the definitions of the frequency range.  That shown is used by the BBC.

 

 

 

 

 

 

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