Můj košík je prázdný



DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN
No. 30/2007 (Sept 10, 2007)
IFA 2007 - growing interest in consumer electronics products in Europe. From August 29 to September 3 there was held in Berlin IFA Consumer Electronics Unlimited exhibition. The organizers claim that the number of exhibitors increased by ca. 15%, and of visitors - by ca. 10%. There were especially noticeable segments of large screen HD televisions and GPS systems. The first one takes advantage of the quickly rising number of HD broadcasts available in Europe.
The confrontation between LCD and plasma TVs, even though manufacturers of the latter vigorously promote their products, is continuously leading to overwhelming superiority in number of sold LCD sets. Nowadays they outnumber the plasma sets several times. Currently the growth in sales of LCDs also applies to big formats, so far dominated by plasma screens. The turning point in winning the market can be the new F9 series of LCD televisions from Samsung. The 52" (130 cm) and 72" (180 cm) models will be available this year yet. The price: 52" - ca. 4.700 Euro, and 72" - 40.000 Euro.
The battle of the HD disc formats still rages on. HD DVD players lead in sales (two times), but BluRay leads in sales of movies (the popular Sony Playstation 3 comes with BluRay capability built in).
The offer of dual players is quite modest - at IFA the HD DVD &Blu-ray models were only presented by LG (BH100) and Samsung (BD-UP500). The picture shows the advertisement of Super Multi Blue player of LG (at IFA).
Where are the towers? - The city located on two continents. It is the only in the world city situated on two continents. The continents are linked with two bridges, each over one kilometer long. The conurbation is inhabited by over 12 million people.
The origins of the city go back to 660 B.C., and its current name is the third one, since 1453, when the city was conquered by the Osmans.
So, where are the towers? If you don't know yet - the answer you'll find at the bottom of this page.
High quality UHF antenna. The antenna Tri-Digital 44/21-69 A2680 is a development of Yagi concept.
Its high gain (17 dBi) and elimination of signal reflections are placing the antenna among the best items available on the market. Next advantage of the antenna is compact construction - typical Yagi antennas that have similar gain are 2 m long, whereas the Tri-Digital - ca. 1 m. So, it is easier to mount the antenna on the mast. The compact construction also makes it less susceptible to wind and other mechanical loads.
No small importance for installers is the time needed for mounting the antenna array. Assembling of typical Yagi antenna of similar parameters may require 40 minutes, this one will be mounted for 5-10 minutes.
The antenna has been equipped with impedance-matching transformer and "F" connector.
The antenna itself has horizontal polarization, but using URI-32Z30 E8792 mount it is possible to fix the array so that it receives vertically polarized signals.

A2682 - Antena telewizyjna UHF Dipol 44/21-69 Tri Eco Digital
DIPOL 44/21-69eco Tri-Digital

A2680 - Antena telewizyjna UHF Dipol 44/21-69 Tri Digital
DIPOL 44/21-69 Tri-Digital




Gain [dBi]






Front/back ratio






Impedance [ohm]



Vertical/Horizontal beam V/H [°]



Length [m]:



Signal measurements in antenna installations. Knowledge of parameters of the signals in the area where antenna installation is to be built is the precondition of proper design and operation of the installation. Most problems are usually caused by inadequate level and quality of terrestrial TV signals, especially when they should be combined with satellite broadcasts in multiswitch installation.A good tool for the measurements is the meter TM 3000 R10502, enabling the designer/installer to measure signals from test antennas. These measurements and catalog data of the antenna equipment will allow to design proper distribution network providing required 62-80 dB level in subscribers' outlets.Main features:
  • Frequency range: 46 - 864 MHz
  • Signal measurements: LEVEL, TILT, C/N
  • Built-in AC/DC voltage meter
  • Audio: built-in AM/FM demodulator
  • Built-in NiMH rechargeable battery
  • LCD display
  • Small size and weight
  • Signal level measurement: LEVEL function
  • Carrier-To-Noise-Ratio measurement: C/N function
  • Measurement of the tilt of the characteristics (using two different carries): TILT function
  • AC/DC voltage measurements up to 100V, with auto-detection function
More about signal measurements in the article Antenna Signal Measurements






Minimum signal level [dBuV]





Minimum normative signal levels at the subscriber's outlets
Higher resolution or more frames per second? The main parameters of IP camera are the maximum image resolution (in pixels) and number of transmitted frames per second (at that resolution). The simplest devices use VGA resolution (640 x 480 pixels) at ca. 15 fps (e.g. K1130). But standard parameters are D1 resolution (720 x 576 pixels) and 25 fps (e.g. K1115, K1131).
An exception to the classification is the category of megapixel cameras. The clear guideline for introducing these cameras has been the fact that capability of picking out small details is more important than smoothness of the images. It is the reason why e.g. the camera IQinvision K1431 working at 2560 x 1920 resolution provides "only" max 10 fps. Comparing parameters of the camera with a standard device, it is clear that the total number of pixels is ca. 12 times larger, so it can be an equivalent of 12 cameras working at D1 resolution (or even 16 VGA cameras).
Depiction of the proportions of D1 image (standard camera) and that of 5 Mpix camera.
Monitoring of dispersed locations - how to lower cabling costs. When the distances between cameras and the monitoring center are long, the cost of cabling is a significant part of the total cost of the whole undertaking. As an example, video transmission from four cameras, located 300 m from the center, means that the coaxial cable will cost about 300 Euro. It is possible to halve the cost using twisted-pair cable. Even gel-filled UTP cable will cost less then 150 Euro. Thanks to TR-4 transformers the video signals can be transmitted up to 300 m.
UTP Video Receiver: TRO-4/400
Video transformers allow to use UTP/FTP cables for video transmission, which lowers the cost of cabling by 50%. Application of the TR-4 M1667.
AI lens - how is it built and how does it work? The iris is the mechanism that can be opened or closed to change the size of the aperture. It controls the amount of light that falls onto the image sensor of the CCTV camera.
AI (Auto Iris) keeps the amount of light at constant level, irrespective of actual lighting conditions. It is opened more or less widely, in inverse proportion to the light stream. The cameras equipped with AI lenses can operate in very changeable lighting conditions. Usually such cameras have to be employed in the case of outdoor applications, working day and at night. The cameras have special connector to control the AI lens. The signal regulates the level of the light reaching the image sensor.
Most of currently manufactured CCTV lenses use DC Iris or Video Iris control. The lenses are comparatively cheap due to clever drive system. In general, the iris my be driven by a small motor (much more expensive solution used in still cameras), or by electromagnetic actuator. The latter solution is commonly used in CCTV lenses, also those offered by our company. The iris mechanism is usually built with 2 small blades that overlap each other, and are operated by small electromagnet.
AI lens without electromagnet cover.
View of electromagnetic actuator and iris diaphragm mechanism with different openings.
In a week - we will examine the electromagnetic actuator that drives the blades.

Hybrid CCTV systems with 4-ch video server: PiXORD P4504. Use of network video recorder/server PiXORD P4504 K2132 provides effective solution for modernization of analog CCTV installation to get IP connectivity.
PiXORD P4504 supports both M-JPEG and MPEG-4 compression. It features "dual stream" function, i.e. it can simultaneously send two video streams from each channel using MPEG-4/MPEG-4 or MPEG-4/MJPEG combination. The device is capable of delivering DVD-quality images from all four channel at the same time. Real-time transmission is performed at 25 fps and 720 x 576 resolution (Full D1).
A distinctive feature of PiXORD P4504 is capability of local recording on hard disc. Two USB interfaces can be used for backup on a pendrive etc.
There are also available two BNC monitor outputs, for the main monitor (current monitoring), and the second monitor that can be used for viewing recorded events. The video server allows not only remote monitoring but also ensures remote configuration and access to archives. On the rear panel there are 4 BNC sockets (Video IN) for CCTV cameras and next 4 BNC sockets (Video OUT - camera loopthrough). This way the image from any camera can be delivered to a recorder or monitor. There are also 4 audio inputs allowing to utilize audio functions of used cameras. The next outputs are S-Video and audio - there is possibility of connecting even regular TV set.
The two terminal strips are RS485 port and alarm input/output connector. Two DB9 connectors (RS232) - CONSOLE and COM2 ports.
In each channel (for the camera) there is possibility of setting areas of motion detection. As the result of the detection the video server can send adequate video record to ftp server or (as attachment) to demanded email address. There are available three authorization levels: administrator, operator, user.
PiXORD P4504 allows control of high-speed PTZ cameras. There are available protocols: Pelco-P, Pelco-D, Lilin, and Dynacolor. The control can be executed either locally, or via Internet browser. An important advantage of the video server is support for RTSP protocol and possibility of remote monitoring and viewing archives with popular media players like Quick Time Player or VLC.
4-ch network video recorder/server Pixord P4504 K2132 with HDD option
Sharing of wireless Internet connection. When we want to use wireless Internet connection we need device supporting WISP mode (Wireless Internet Service Provider), enabling configuration of its wireless port as WAN port, i.e. as the standard port of the router. It will enable us to route internal packets and create our own network. The router may be directly connected to an outdoor antenna through 50 ohm coax (e.g. Tri-Lan 240).Recommended devices:
  • the router TL-WR543G N2955, with WISP function. The computers are connected to the router with UTP cable. When we need larger number of ports, we use 5-port switch TL-SF1005D N29915, or 8- port device TL-SF1008D N29918,
  • when we want to share the signal wirelessly we should also use an Access Point, e.g. TL-WA501G N2940, because it is impossible at the same time to receive and broadcast the signal in WISP mode of the TL-WR543G N2955. The Access Point has to be connected to one of LAN ports of the router or mentioned above additional switch.
Home and business Wi-Fi networks - applications of TP-Link family
Access Point: TP-Link TL-WR543G - eXtended Range <br />(router &4-p switch, WISP, 2.4GHz)
Sharing of wireless Internet connection.

Engagingly about antennas - VI Summer 2007 Dipol Competition - the entries.
Engagingly about Antennas - VI Summer 2007 DIPOL Competition
"Among pools of Narew" - Mariusz Mikolajewicz
Istanbul. Throughout its history, the city was also called Byzantium and Constantinople. Nowadays, the larger part of the conurbation lies on the Asian side of the Bosporus Strait, but the most interesting monuments, including Haggia Sofia and Blue Mosque, are situated on the European side.
The array of telecommunications towers in the picture has been built on Camlica hill. The highest one is TV tower, 166 m high, on the Asian side. The second TV tower in Istanbul, even higher (233 m) is situated on the European side and is called Endem.

Antennas in Turkey
Osoby mající zájem o zasílání týdenního Newsletter elektronickou poštou, prosímme, uveďte svůj e-mail: