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Recollections of BBC engineering from 1922 to 1997 |
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Designs Department - Sections |
MeasurementsEarly television measurementsIn 1949, a video frequency oscillator, a video frequency amplifier detector, a test pulse generator, a waveform monitor and group delay measuring equipment were developed by SHP, ARAR and SNW. They were needed to maintain good performance of the nation-wide network of television transmission circuits. Pulse & BarIn 1954, new performance measurement techniques were developed, such as “pulse and bar”. Due to the need for new types of equipment using these techniques, Designs Department’s Measurements Section was formed under the leadership of LEW. Colour television measurementsA complete range of test equipment to meet the requirements of colour transmission was developed in 1966. One unit, the Non-linearity Test Signal Generator, included an unusually large number of functions and covered a complete range of tests on both monochrome and colour transmission. In 1971, a field interval noise measuring set and a gated noise measuring set were designed. Both of these measured the signal-to-noise ratio in the presence of a signal. Audio measurementsA combined AC test meter and variable frequency tone source was designed in 1972, together with high pass filters for the measurement of harmonic contact. Pulse duration meterIn 1972 a pulse duration meter was designed and it was one of the first TV measurement instruments to have a digital display.
Example of a design from 1961 - UN1/511/183Signal Measuring Unit used with oscilloscopes for accurate measurement of signal amplitude. It is described in this Technical Instruction and it must have been one of the first DD designs using transistors: four OC140.
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