TV & SAT TV
Locations and parameters of terrestrial digital and analog TV transmitters in Poland
Locations and parameters of terrestrial digital and analog TV transmitters in Poland (information suitable for Polish-speaking users only, available when you choose the Polish version of the website)
DIPOL for education - SMATV and CCTV systems
The article presents proposals to build examination stands in technical/vocational schools. Additionally, it lists other articles that can help understand some practical issues connected with electronics.
Distribution of digital signals in cable TV systems
QAM modulation is optimal for cable networks. It is used in cable band/hyper-band (S channels) and UHF band. Due to the need of compatibility with channel raster and transmission requirements, there are used 8 MHz channels (MPEG-2 compression, QAM modulation).
Maximum output level in active elements of community and cable networks
One of the important parameters of amplifiers is their maximum output level. It is the level which can appear in the amplifier output without exceeding an acceptable level of nonlinear or crossover distortions.
Digital satellite broadcasts
Thanks to digital technology, satellite industry has increased the number of channels that are broadcast from one transponder - there may be transmitted 5, 8, or even more TV programs. It lowers operating costs and makes possible to multiply the offer from a single satellite. The important factor is compression level that can be changed according to the intended quality of the image.
Electromagnetic compatibility (EMC)
RF cable network should fulfill regulations of electromagnetic shielding. It cannot radiate energy that exceeds determined level and it should be resistant enough to outer electromagnetic radiation.
Compression of video and audio signals
MPEG-4 is the newest video compression standard which quickly becomes popular, also in the case of video streaming. In comparison with previously presented standards, it integrates effective methods for multimedia data.
Data transmission via cable TV networks
There are usually used only 60 channels for television transmission. On the assumption that, for the reason of possible distortions, there are left free the channels of terrestrial transmitters (usually 8) and 4 channels for modulators (of e.g. VCRs), it is still 22 channels available for data transmission.
Separation between outputs of splitters
Separation between outputs of splitters (crosstalk attenuation) is very important parameter of the devices. It determines level of interferences coming from other branches of the network connected to the splitter. It should be as high as possible.
Measurements and amplification of DTT (DVB-T) signals
An article on the measurements of signals in DVB-T systems. It explains the meaning of the measured values for the quality of reception. The part concerning the amplification of the signals allows for better choice of RF amplifiers, especially in the transitional period (from analog to digital TV).
Symbols used in diagrams of antenna installations (Polish norm)
Symbols used in block and wiring diagrams of community antenna installations in Poland (information suitable for Polish users only)
Filters in TV antenna installations
An ideal band-stop filter has no attenuation in the pass-band, 90-degree steep slope, and infinitely high attenuation in rejection band.
TV Channels (PAL BG/DK)
TV channels used in Poland and some other European countries for terrestrial and cable TV broadcasting. In Poland there is used PAL DK standard, with continuous numbering (e.g. after S8 we have S9). We have also presented PAL BG channels used mostly in Western European countries.
Conversion Table - dBuV to uV/mV
In the table there is comparison of signal level and corresponding voltage.
In the Home (10)
SMATV Systems (9)
Some Theory (14)
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