Choosing and installation
Digital DVB-T TV receiver and converter should meet minimal technical demands compliance with standard and standard accepted by Azerbaijan Republic.!
Devices receiving digital DVB-T TV divide the following types:
1) Digital converter or digital set-top-boxes
To receive digital TV, the most spreading and more affordable price is simple devices.
These devices look like little video recorder or DVD for its external appearance. This device is connected to TV by reception antenna used in ordinary analogue TV and SCART, RGB or HDMI type inputs. Changing of channels and etc functions are realized by remoter of that device.
2) Digital converter devices with different functions and CAM module
These digital converter devices differ for additional functions from devices noted in the first item. These converter devices have hard disk for recording of programs and CAM module giving opportunity to show closed channels (paid).
3) TV with digital TV receiver
These TVs allow you to receive both analog and digital TV channels. Such TVs considered more suitable. Any additional cable or remoter is not need to use. The quality of description on these TVs is the higher than ordinary converter devices. In spite of it such TVs should own CAM module to show closed (paid) TV programs. Currently, the majority TV producers realized production of such TV and possible to such TV from magazines of our city.
4) Different additional modules working with connecting to computers and special software (USB, PCI, PCIE or PCMCI
Bu qurğuların istifadəsi üçün kompüter biliklərinə sahib olmaq lazımdır.
It is possible to show DVB-T TV on computer or TV programs on the screen of TV with connecting to computer TV by means of such devices.
It is necessary to own computer knowledge to use these devices.
The appropriate certificate is provided by MICT testing of converter devices for conforming digital standard (DVB-T MPEG4) accepted in Azerbaijan and supplying of reception with quality of digital DVB-T TV programs in the territory of republic. The list of receiver and converter devices received certificate. It is considered necessary to determine certificate of MCIT while buying those converter devices. MCIT does not guarantee against converter devices are not certified for acceptance of failure or of poor quality of TV programs.
How to choose converter devices?
MPEG4 is accepted as squeezing method of TV programs in accordance with “Application and development program of DVB-T digital TV broadcasting system” in the territory of Azerbaijan Republic confirmed by decision No 26 of the Cabinets of Ministries.
DVB-T digital TV broadcasting network is installed in accordance with DVB-T MPEG-4 standard considering above-mentioned in the territory of republic. That’s why it should be specified supporting of DVB-T MPEG-4 standard when buy digital converter devices or TV with converter device. If you want to show closed (paid) channels can be applied in the future, then is need to pay attention having CAM module of that receiver or converter devices.
Which converter devices for DVB-T TV reception is not worth buying?
This web stores and more are from foreign countries who want to get the converter devices. So, in this way the possibility to use converter devices and TV sets across the country to make sure that you really need.
It is belong to persons who want to buy converter devices from especially web stores and foreign countries. It is necessary to be sure really possibility of usage converter devices or TV buying with that method in the territory of republic.
The following converter device and TV for receiving DVB-T TV in the territory of Azerbaijan Republic is not possible to use:
– DVB-C receivers (it is meant for cable network)
– DVB-S receivers (it is meant for satellite network)
– IP-TV receivers
– DVB-T receivers meaning MPEG-2 video encoding
Installation of converter devices for receiving digital TVı
The converter devices for receiving digital TV should be installed in accordance with the following scheme.
The reception of the digital TV programs depends on the right choice and placement of antenna. It is possible to watch TV programs in low quality in the case of the wrong selection or incorrect direction of antenna in analogue TV, but depending on the choice and placement of the antenna, it is impossible to watch TV programs in digital TV when TV signal is lower than the adopted norm.
Therefore, the advice of the specialist should be taken into account while selecting and placing of the antenna.
Television signals as light are broadcasted rectilinearly from the tower and they have no the feature of bending on the surface of earth. Therefore, if the TV tower is higher, the coverage area of TV broadcasting will be larger. However, the distribution of TV signals depends on the various buildings, relief, and landscape, the power of the transmitter and the configuration of the antenna system. In Appendix 2 the coverage area of the digital TV broadcasting in the territory of the Republic of Azerbaijan is shown on the map. In settlement the antenna for the reception of the digital TV should be installed according to the coverage area of the TV station covered the same settlement (see the table). If the settlement is located away from the TV tower, in this case receiving antennas with intensifier should be used.
Information about the receiving antennas recommended by MCIT
Modern antennas with intensifier ensure to strength the signal up to 17-18 decibels (dB). Depending on the model, the minimal level of the input signal should be 30 dBmkV in converter/ receiving devices. Based on the experience, it can be noted that in order to get 100% of the power level of the signal in the converter device, the input signal should be 35-50 dBmkV. In order to get 50% of the power level of the signal, the input signal should be 30-35 dBmkV. But these indicators may be different in various receivers. In other words, if the level of TV signal is lower than the norm, it will lead to the image freeze on screen, creation of the squares and eventually will cause the image loss.
The choice of antenna
Antenna system provides the reception of the electromagnet waves through air and transmission of these waves via cable. The strengthening of the antenna depends on the number of its elements. If the number of the antenna is more, the strengthening of the antenna will be greater. However, in order to strength the antenna, radio technical schemes are applied too.
According to the Regional Agreement Geneva 2006 frequency bands of meter (VHF) 174-230 MHz (6-12 TVK) and decimeter (UHF) 470-862Mhs (21-69Mhs) are allocated for the digital broadcasting.
Frequency band of 470-490 MHz (UHF) (21-60 TVK) is used for the digital TV broadcasting in our republic. This information should be taken into account while selecting the antenna.
Difficulties appearing in receiving process and eliminating them
In order to avoid the problems in receiving process, first of all, it should be used the receiving/converter devices and antenna systems which have certificate given by MCIT.
The weather conditions and the seasons of the year may affect on the power of the digital TV signal.
The following factors cause the decreasing of signal power:
– Rain and snow
– Snow melt
– Leaves falling
– Trees covered with snow or wet trees
– Fog and so on
The power of the digital TV signal may vary per day in the areas where the signal level is close to minimum. In other words, there may be obstacles in the image receiving during the different hours of the day. Changes in temperature and other harsh weather conditions may also influence on signal broadcasting. In summer received signal level in the residential areas near to the forest is 3-4 dB (about 30%) lower than winter. The main reason is that the definite part of the power of TV signal is absorbed by the leaves of the trees in summer. In some cases, reflection of TV signals from the landscape or multi-storied buildings causes the increasing of signal power in reception and unlike analogue it leads to qualitative reception of TV programs. In this case, the direction of the receiving antenna should be diverted to the reflected signals. If there is no transmitter with low power nearby, receiving antenna should be directed to television tower which has TV transmitter with high power (see table) (for example, DVB-T TV signal is not received from Teletower in Hovsan, Garachukhur and surrounding areas of Baku, it is received from TV station which is installed in Gunashli settlement ). In any case, it is possible to rotate the receiving antenna in different directions for normal reception of TV signals and to define the optimal placement of the antenna for power level of the signal on screen (by pressing the button of info or other proper one).