carrier frequencies of the various transmitters. An instrument is being
designed incorporating novel techniques which will enable measurement to
be
carried
out
to
the
high
accuracy
required
using
inexpensive
equipment.
Standard Equipment for the Insertion of Test and
Data Signals into the Television Waveform
There has been, in recent years, a steady demand for signals to be added
to the television waveform for the purposes of monitoring and control.
This has led to the undesirable proliferation of signal inserters each
designed to meet a particular requirement. The new equipment is being
designed to act as the focus of the various signal to be inserted into
the television waveform.
Methods of Audio Measurement
In co-operation with senior members of other departments the preparation
of standard instructions on methods of Audio measurement is in hand.
Methods of Video Measurement
In co-operation with senior members of other departments the preparation
of a standard instruction on methods of Video Measurement is in hand.
Audio Frequency Non-Linearity Measurement
Research Department have developed a novel method of measuring audio
frequency non-linearity which promises significant advantages over
traditional
methods.
An
investigation
is
being
carried
out
in
conjunction with Operational Departments and Research Department to
evaluate the practical use of the new method.
Appraisal of Commercial Oscilloscopes
A number of instruments have been assessed with respect to their
suitability for use in the BBC. Discussions with manufacturers continue
in order to resolve unsatisfactory aspects of performance and to obtain
modifications suited to the BBC's needs.
A list of Oscilloscopes and Waveform Monitors recommended as suitable
for BBC use was issued in May 1977 and updated in October.
Tie Line Equalisers
A simple equaliser comprising only capacitors and resistors has been
developed for the equalisation of short tie lines. The new equaliser is
specifically for use with a new design of distribution amplifier and is
expected to be used in large quantities throughout the Television
service.
Carrier Programme Circuits for Stereo Sound Programmes
The Post Office circuits presently being used to carry stereo
contributions between Regional Centres and to London will no longer be
provided in their present form and the circuits which the Post Office
intend
to
provide
as
replacements,
are
not
suitable
for
stereo
transmission. In collaboration with Communications Department a method
of using Carrier Programme circuits to meet this need is being
investigated.
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