Modern community antenna installation (MATV/SMATV system)
Tu obsiahnuté informácie môžu byť neaktuálne.
Properly built antenna installation ensures perfect reception of television and FM programs, as well as:
- Possibility of Internet access and connected services (e.g. IP phone)
- Possibility of transmitting images from CCTV cameras.
Through adequate selection of devices the installer should guarantee maximum reliability of the system and customers' satisfaction.
Modernization of old installations.
Community installations created in the seventies don't fulfill basic requirements of quality and reliability. They were usually designed for distributing two, three programs. Nowadays, the number of terrestrial TV programs available in big cities is 3 times higher, not to mention possible distribution in the network a number of satellite broadcasts. The terrestrial programs are mostly transmitted in UHF band, often not planned to use in these installations (big attenuation).
How to modernize such an installation?
The installer should examine the network and measure characteristics of the cable (or at least attenuation for a number of frequencies), to suggest one of the two solutions:
- Saving the original cabling and mounting channel converters CO-405/705 (R905079) and channel amplifiers ZG-601 (R90538). It will allow to regain good quality and improve reliability of previously distributed channels, and some space for next ones.
- Replacing the cabling and mounting channel amplifiers ZG-401/601. This solution allows to transmit a large number of channels and provides possibility of adding some satellite channels, as well as makes possible for some subscribers to use cable TV service (if available in the area).
When calling a bid, the contracting party (investor) should realize that only channel amplifiers, due to independent gain adjustment in each channel, are capable of balancing the levels and providing good reception of all channels.
Channel amplifiers also allow to increase in easy way the number of offered channels, enabling installation of satellite headend station.
Improper selection of amplifiers may cause problems with future work of the installation! In the case of a cheap amplifier, increase or decrease of the power of a transmitter will be hard to compensate, or even will require to change it for a better one. Similar problems, especially in the case of distant transmitters, may be caused by propagation changes. To win the competition, some installers offer cheap equipment that does not guarantee proper quality. So the bid terms should include the main requirements concerning the preffered solutions.
How much do channel amplifiers cost?
The price of typical set of channel amplifiers per single outlet (for a 100-outlet network) is ca. 5 EUR (half of the cheapest individual antenna!!!).
Headend station for apartment house, hotel or boarding house.
To increase the standard of service, owners of hotels etc. usually offer their guests access to satellite broadcasts.
For the reason of possible damage, problems with control etc., it is not recommended to equip the rooms with satellite receivers. Use of headend station eliminates the problems - in the rooms there are needed only televisions.
Headend station is built on the basis of panel digital receivers, of which every single unit is programmed for reception of individual satellite channel.
Headend station from ALCAD for community reception of satellite programs
It is a mistake to employ in community installations popular individual sat receivers! They are not prepared for continuous work and do not ensure quality and reliability needed in professional installation.
A dream of every estate manager is facades without satellite dishes - it may come true due to employing set of IF/IF converters
The most modern and relatively cheap solution, designated for housing cooperatives, condominiums etc. is set of satellite IF/IF converters. Such conversion allows easy distribution of satellite programs. The programs are received with individual sat receivers.
This solution eliminates tens of private dishes mounted on balconies, elevation, or on the roof. The individual receiver is connected by the user directly to satellite outlet, without any additional means. Usually such installations also provide terrestrial TV programs (another socket in the outlet).
Picture of IF/IF converters
Satellite installation with multiswitches
Multiswitches also allow distribution of satellite signals from single dish to multiple satellite receivers. Generally, they are used in installations up to 100-200 subscribers. Greater number of subscribers would complicate the installation and rise the costs.
View of MS-952 R70952 multiswitch
Extension of existing community installation to next buildings
In the case of several to dozen buildings in a limited area (e.g. a condominium), there is possibility of using common set of terrestrial and satellite antennas (dishes) and one headend station. This solution significantly decreases costs, especially when extending the offer by satellite channels, e.g. with use of IF/IF conversion.
The installation should be based on previously described solutions with channel amplifiers, IF/IF conversion, or headend station. In order to ensure further distribution it is needed to use adequate building amplifiers i.e. CF-115, CF-116, CF-716, DA-713.
The amplifier DA-713 R904025
Building of large network has to be necessarily preceded by detailed design that includes influence of the distances (parameters of the cables) etc.
The contracting party should remember that the cost of any kind of community installation doesn't exceed the total worth of individual installations. Besides, such community installation doesn't mean that the subscribers have to pay much - it may be several times cheaper than cable TV. The operating costs are only quite small payment for energy supply, and maintaining (periodic technical inspections).
NOVINKY V KNIŽNICI
Systémy založené na optických vláknach sú stále obľúbenejšie. Všeobecná dostupnosť relatívne lacných prístrojov konverzie elektrických signálov do... viac »
Článok uvádza príklad ukončenia FTTH siete založenej na tzv ľahko prístupných kábloch. V súčasnej dobe je použitie ľahko prístupných káblov optimálnym... viac »