Video cassette recorder

Taskl

Tuning-in

Read this newspaper article:

High-tech mystery

High-tech machines leave many owners baffled, according to a survey by electrical retailers. Nearly a third of those with video recorders and 57 per cent of camcorder owners do not use all the functions. The 16-24 age group understood the technology best, with 70 per cent saying they were the family expert.

Survey your group. Ask these questions:

1. Does your family have a VCR?

2. What is it used for?

3. Who knows how to set the timer?

4. Does your family have a camcorder?

5. What functions are not used?

Task 2

Task3

El

You are going to hear a short talk. The speaker will explain some of the differences between conventional audio and video recording. Before you listen, note down any differences you already know.

Now listen and complete this table to show some of the differences between audio and video recording.

Audio

Video

Medium Tape width Type of heads Speed (cm/sec) Scanning

Data recorded in 1 sec.

magnetic tape \ inch

linear

magnetic tape

2.339 (VHS)

2 5 complete separate pictures

Task 4

Read this text and match each change in VCR design with its result, as in the example below.

The step from recording sound on magnetic tape to doing the same with video signals is one of increased band width. Early reel-to-reel machines used one-inch wide tape and made the most of the available band width by moving the tape past the head at high speed. 5 Unfortunately, this meant that the transport mechanism had to be built to a high specification.

Improvements in magnetic tape and the use of helical scanning meant that far more data could be crammed into a smaller area. By spinning the head at a high speed, the rate at which the data could be stored or 10 retrieved was increased. Aligning the head at an angle to the tape laid down the information as a series of slanted tracks. This allowed the cassette tape to be narrower and move at a slower speed, giving rise to the modern video cassette recorder.

Early VCRs were playback-only, but by building in a full-colourTV 15 tuner, programmes could be recorded from the air while another channel was being viewed on a normal TV. The inclusion of a timer meant that recordings could be made and viewed at a later date. Early timers only switched the tape on at a certain time, leaving the VCR running until the tape finished. The latest machines allow a large 20 number of on/off programmed times to be set so that viewers can go . on holiday and not miss a single episode of their favourite soap opera.

Design change

Example moving the tape past the head at high speed

1. improvements in magnetic tape and the use of helical scanning

2. spinning the head at a high speed

3. aligning the head at an angle to the tape

4. recording information in slanted tracks

5. all these improvements

6. the inclusion of a timer

Result

The transport mechanism had to be built to a high specification.

a The information was laid down as a series of slanted tracks.

b The modern VCR could be produced.

с Far more data could be crammed into a smaller area.

d Recordings could be made and viewed at a later date.

e The rate at which the data could be stored or retrieved was increased.

f The cassette tape could be narrower and the tape could move at a slower speed.

Language Study Change and result

Study this design change and its result:

spinning the head at a high speed The rate at which the data could be

stored or retrieved was increased.

We can link a change and its consequence in two ways:

1. Spinning the head at a high speed meant that the rate at which the data could be stored or retrieved was increased.

2. As a result of spinning the head at a high speed, the rate at which the data could be stored or retrieved was increased.

We can use these methods when the change is a noun or a noun phrase.

Task 5 Link the other changes and results in Task 4, using both these methods.

Task 6 Label the numbers in the diagram on the following page using the terms in