Question 5
- Classify the following television receiver controls into operating and service controls in
Table 3.
volume control
brightness control
ON-OFF switch
tone selector
height control
horizontal hold control
AGC control
vertical linearity control
fine tuning control
contrast control
channel selector
width control
Table 3
Operating control |
Service control |
|
|
|
|
|
|
|
|
|
|
- Fig. 3 is a chart of additive colour mixing used in television receivers. Name the colours
in the pat labelled W, X, Y and Z.
W:_______________________________ X:_______________________________
Y:_______________________________ Z:_______________________________
- To produce the colours given in 5(b). the picture tube of a colour television receiver
possesses some components. State:
- Three components mounted on the neck of the picture tube;
- Two components within the picture tube.
Observation
The expected responses were:
Table 3
Operating control |
Service control |
Volume control |
AGC control |
Tone selector |
Height control |
Contrast control |
Vertical linearity control |
Brightness control |
Width control |
Channel selector |
Horizontal hold control |
On-off switch |
|
Fine tuning control |
|
(b) Colours of the labelled parts in Fig. 3
W: Red
X: Blue
Y: Green
Z: White
(c) (i) Components mounted on the neck of the picture tube
- Deflection yoke assembly
- Convergence yoke assembly
- Centering magnet
- Pin cushing error magnet
(ii) Components within the picture tube
- Colour Adder
- Colour Matrix
- Electron guns
- Deflection plates
- Phosphorescent (material) screen
- Focus screen
.
The reported stated that question 5 was unpopular among candidates as only a few of them attempted it.