LEARNING REPAIR TELEVISION

TV RECEIVER BLOCK DIAGRAM

Figure 1. Block Diagram of Black and White TV Receiver

 

Figure 2. Colour TV Receiver Block Diagram

 

Before we study the working principle of a TV receiver, it is worth knowing a little about the passage of an object image that we usually see on TV. Images that we see is the result of production of a camera. Object lens of the camera captured images will be separated into three primary colors, namely red (Red), green (Green) and blue (Blue). The results will be emitted by the TV transmitter (Transmitter) form cromynance signal, luminance signal and syncronisasi.
In addition to the picture, television transmitters also carry voice signals are transmitted along with the image signal. Images transmitted by the system amplitude modulation (AM), while the sound system with frequency modulation (FM). The second system is used to avoid noise (noise) and interference.

 

Figure 3. Object to the distribution of television

 
2. STANDARDS AND TV CHANNEL TRANSMITTER
Groups defined frequencies called a channel for transmitting signals (channels). Each has a 6 MHz channel in one area of ​​the frequency (band) is allocated to the commercial TV broadcasters, namely:
a) VHF channel low-frequency fields from 2 to 6 (54-88 MHz).
b) the field of high frequency VHF channels 7 to 13 (174-216 MHz).
c) UHF channels 14 to 83 (470-890 MHz)
There are 3 TV transmitter systems, as follows:
a) National Television System Committee (NTSC) used USA
b) Phases Alternating Line (PAL) used English
c) Sequential Couleur a'Memorie (SECAM) used French
While Indonesia itself uses the PAL system B. This system distinguishes it is the image format, the picture carrier frequency range and sound carrier.
3. PRINCIPLE TV RECEIVER
Model and TV series of block types vary, depending on the brand of TV that is used.
Broadly speaking, the block has the following functions:
a) Antenna Television
TV antennas capture RF signals of a television transmitter. Antennas are classified by construction there are three, namely:
1) Yagi Antenna
2) The period of logarithmic Antenna
3) Antenna loop
Another classification is based on the received wave frequency bands are:
1) Low VHF Channels
2) High VHF Channel
3) Channel UHF
(a) Antennas VHF Low 

 

(b) Antena VHF height

 

(c) Antena UHF

 

Antena Perioda Logaritmis