can absorb a considerable amount of effort. This year we have
collaborated with Transmitter Group in making extensive investigations
and improvements which would appear to have dealt with the majority of
the difficulties.
Apology Captions
Apologies for fault conditions should be immediate and should avoid
unnecessary disturbance to viewers not affected. A number of caption
generators are being installed at strategic transmitters, each capable
of superimposing one of a limited number of pre-programmed captions.
This operation will be controlled virtually by the M.I.C. operator and
integrated with the service provided by studio presentation.
Data Transmission
The need for specialised control and switching systems has continued
through the year and equipment is being provided for the following
operation:- Remote control from London of Channel Island opt-out
facilities; Remote control from Dublin of vision and sound switching
matrices in Belfast; Remote control and telemetry between Television
Centre and Mi11bank Tower for ENG aerials and receivers; Telemetry of
2GHz carrier level received at Mi11bank Tower to ENG vehicle.
Signalling over existing transmissions is economically advantageous.
Units for 19kHz and 23kHz sound subcarriers on UHF/TV have been produced
and investigations into the possibilities of using a 76kHz subcarrier on
VHF/FM transmissions is in progress. An adaptive coder and decoder have
been developed using a microprocessor.
This project is being used as an exercise in microprocessor programming
techniques as well as providing equipment for operational service. The
design work involved is also applicable to the M.I.C. collator.
The scheme involves the entry, storage and display of work schedules for
the Scenic Services at Television Centre. The equipment comprises a
commercial visual display unit with keyboard and floppy-disk store both
being microprocessor controlled. Data is displayed at various locations
on standard 625 line picture monitors.
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