of the digital
applications such as special effects and possible mixer
have been considered as extensions to general purpose use
field-store development for the new standards converter.
Disk Reproducer Turntable
An installation kit using a Technics direct drive turntable,
manufactured to BBC requirements, has been finalised and is to be used
initially for improving existing dual disk reproducers. Twelve units
have been manufactured for use in selected stereo installations. The
kit has also been chosen as the turntable component for an entirely new
Testing of Commercial Equipment
To guide users, a number of commercial Sync pulse generators have been
evaluated and their specification and performance compared. The object
is to ensure that the BBC gets value for money and a technical
performance compatible with present and future practice.
PROJECTS IN PROGRESS
The initial project yielded a demonstration prototype of major converter
components. Development continues under the following headings;
Digital Store: This design has been
The associated store control board
finalised for quantity production.
is being designed for four field
Clock Generators: Development has started on the clock generators
needed for colour operation.
Arithmetic Function Generator: The first version of the multiplier card
operated successfully in the prototype equipment; an alternative design
reducing the package count by a factor of three with LSI devices has
been built and evaluated.
Decoding and Coding: The full development of a comb-filter analogue
decoder is to follow from the demonstration of the signal quality
improvements evident with this technique, many applications apart from
possible use in converters are foreseen. Commercial SECAM equipment has
been evaluated and some modifications for BBC use agreed.
Standards Converter Control: Remotely controlled equalisers and video
source selection equipment based on existing designs is being assembled
so that the converter can be controlled remotely.
Systems Monitor: Development of a microprocessor based monitoring
system which will signal the operating mode and incidence of faults via
captions superimposed on the output picture-monitor has been started.
The following designs are underway to increase the versatility
measurement and control support.
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