DIPOL Weekly Review – TV and SAT TV, CCTV, WLAN

China is building the world's largest wind turbine.

Chinese energy company MingYang has announced the MySE 18.X-28X offshore wind turbine project. The giant generator will reach the height of a 70-story building, be equipped with 140-meter-long blades and cover the area of nine football fields with its surface. Taking into account the average annual wind speed of 8.5 m/s, the turbine will be able to generate 80 GWh of electricity per year. The company claims that this amount of energy will be enough to supply 96,000 residents while reducing CO₂ emissions by more than 66,000 tons. Plans are also made to install a holographic MPC sensor and a digital DTC sensor that can protect the giant wind turbine from the most extreme conditions that can occur in the ocean – winds in excess of 56.1 m/s.

The MySE 18.X-28X project is a major step toward accelerating the transition to green energy. The work on the giant wind turbine is still underway, and MingYang hopes to report on progress in the near future. China is the planet's most polluting country, producing about 14% of total global gas pollution. The new turbine is part of China's plans to achieve zero-carbon by 2060.

ALCAD brand channel amplifier with auto-configuration.

One of the main problems in building and launching SMATV systems is large disparity in signal levels between individual multiplexes. While in smaller DVB-T2 systems this is of little importance (due to small distances from the antenna to the receiver and a small number of outlets), in the case of more extensive systems such differences are crucial for the proper operation of the entire system. The key reason for the different signal levels for individual DVB-T2 multiplexes is the non-uniform attenuation of frequencies in different environments, e.g. air, coaxial cable, etc. These disparities increase with the distance and frequency. Other important reasons that cause disparity in signal levels can be:

The ideal solution to eliminate the above problems is to use the CAD-804 R82620 channel amplifier from ALCAD.

The installer can freely configure the VHF/UHF inputs and optimize the individual channel levels at the installation site to ensure high-quality picture on the TV screen. The CAD-804 ALCAD channel amplifier can be used independently - as part of a multiswitch system or as part of a headend (AiZ). The auto-configuration function automatically searches for all DVB-T2 digital multiplexes with signal levels above 55 dBμV.

Adding cameras to a Hikvision DVR from the local network using Batch Configuration.

Batch Configuration software, in addition to the many functions it offers – such as group upgrades and resetting devices to factory settings – allows you to add IP cameras to the DVR. To use this feature, first add the DVR to the software, then go to the Add IPC tab. To add cameras that are on the same local network as the DVR, select Online Device. After finding and selecting devices and entering login information, they will be automatically added to the DVR.

Wifi network in a restaurant.

Restaurants, large stores, airports are very demanding places to build efficient Wifi networks. Due to the large number of visitors, it is advisable to use a proven Omada system that will provide stable wireless connectivity to the Internet. When the system is inside a building the best choice is the TP-LINK EAP620 HD N25691 access point. The device operates in 2.4 GHz and 5 GHz bands. In the case of such devices, the maximum number of users connected to one access point is more important than the range. It is recommended not to exceed 50 users in one band (if the device supports both 2.4 and 5 GHz band it can connect up to 100 users). For outdoor gardens, the EAP610-Outdoor N25693 is recommended.

With the Load Balance function, the device will automatically switch the user to a less loaded AP when the maximum set number of users is exceeded. This function enables also switching users to devices with stronger signal, e.g. when the user moves around the restaurant. Another important function is Band Steering enabling even distribution of users between 2.4 and 5 GHz bands.

Checking the continuity of a fiber optic cable using an OTDR.

The cabling work is always one of the most time-consuming, and therefore also costly, stages of any installation project. For fiber optic cables, where improper transport or storage can cause damage (micro-bending), it seems particularly important to have it checked before laying in the cable tray, manholes, walls, etc.

Theoretically, a light source and a power meter can be used to check the cabling, but this is usually made much more difficult by the lack of access to the other end of the cable when it is wound on a reel. If this is the case, use an OTDR. The whole process comes down to terminating the available end with a pigtail (splicing), and then connecting the OTDR to it. Of course, with such a measurement, the incidence dead zone of the OTDR will prevent us from verifying the first few-odd meters of cable. In order to verify the entire section of the cable being laid, use an additional launch cable.

The whole process of checking the cable on the drum takes a few minutes and allows the installer to avoid the disastrous deployment of a damaged cable. The following figure shows an example of reflectometric measurement of a 500-meter section of optical fiber wound on a drum. This cable was probably damaged at the stage of production.

Fresnel zone. It is important to realize that the range of a wireless network depends on many factors, some of which we can influence and others are unknown. Fresnel zone is one of the most important concepts appearing in radio subjects you absolutely must be familiar with. It is the area actively involved in the transmission of radio signal energy. The shape of this area in longitudinal section is an ellipse, and in cross-section it is a circle. The radius of this circle varies along the length of the entire radio link and assumes a maximum value in the middle of the distance between the antennas. The first Fresnel zone is the most important, since it is in this zone that almost all the energy of the radio signal is transmitted...>>>more