Systems of Wireless Signal Transfer DynaPix Triad of DTC Communications Company

By Marina Ablogina

Review contents:

Wireless Systems for Sound and Video Transfer from Camera Systems of Wireless Signal Transfer DynaPix Triad of DTC Communications Company Equipment of GMS Company Digital wireless system of receiving-transfer of sound and image signals of Grass Valley a Thomson Brand Company On-camera WRP20 System of IRTE Company (Italy) Wireless Transfer of Data from DY-DV5000 Camera with the Help of KA-DV 5000 Adapter Link Wireless Camera System is New Equipment form New Manufactures Swiss Wireless COFDM Systems Livetools in Russia Miniature Color Microdic Video Camera with Transceiver Wireless Systems of Video Transfer from Premiere Wireless Tandberg Wireless Operators’ Systems Reporter’s Radio Extender Teleview Reporter is Wireless Digital System of Video Signal Transfer “Camera-MTU” Transvideo wireless systems

Not so long ago the picture where sweaty operator is running along the field, for example during football game was and a cable of camera channels stretches after him was so real that it didn’t surprise anyone. Today such picture provokes amazement, but doesn’t stay without attention.

Directors’ dreams about that free movement of operators was not limited with anything is gradually coming true. There appear systems, which provide high mobility during working with cameras.

In this article we are going to talk about wireless systems of signal transfer, their pluses and minuses, criteria, that you should consider when buying facilities so that they would simplify work significantly and didn’t lower your budget too much.

For the beginning we would like to say few general words about these systems. Wireless systems of signal transfer are used were connection with base station with camera with the help of cable becomes problematic. Independent from the ways of application all of them are different in quality level and distance of action, i. e. on what maximum distance operator can distinguish from base station without significant losses in signal quality, what influences the price. Quality of receiving and stability to influence of numerous external factors (noises created by different objects, radio signals of adjacent frequencies, etc) also influence the price of these systems.

Besides operating period of systems of wireless signal transfer depend a lot on power supply, more specifically, from accumulators set on the camera. That is why during operating it is necessary to use only checked batteries. Of course, it is possible to organize a power supply from mains, but than the sense of all wireless system is lost.

All systems of wireless signal transfer can be relatively divided into two groups, that can be, which different in the sphere of application, weight, power consumption and price:

• transmitters set on camera, equipped with special scheme, which controls position of transmitting antenna relating to receiving antenna. Signal from tracking adapters come to the scheme, which then control rotary mechanism of antenna. That is why as a consequence weight and power consumption of system increase. It can be applied during filming in places of mass crowd of people;
• transmitter is situated on the camera and 3…4 antennas are set in places of presumable camera operating. In that case the system switches to the antenna from which signal of maximum level is coming. Summary cost of complex that consists of transmitter and few receiving antennas increases comparing with the first system, but power consumption of facility set on the camera will be lower.

So first system is cheaper and somewhat even more mobile than the second why, but on the other hand, second system has smaller weight and consumes much smaller energy. That is why during choosing system it is necessary to consider next factors:

• the necessity of application of some creative decisions;
• remote of operator from receiving antennas;
• power consumption of the system set on the camera;
• weight of the facility;
• private plan of region.

Only after detailed analysis of all above positions it is possible to make a right choice and later use maximum opportunities of bought facility.

D&K Corporation presents a system of wireless video signal transfer DynaPix Triad of DTC Communications Company. Three receiving antennas of standard configuration (it is possible to increase amount of antennas up to five) and transmitter are included into DynaPix Triad system. DynaPix does a transfer of high quality image (NTSC and PAL) and stereo sound from the camera to receiving station on the distance of up to 300 m. Signal transmitter is set on the camera and its power supply is done through one of on-camera batteries. Receiving antennas can be situated on the top of mobile television unit, on walls of studio, etc.

In DynaPix Triad each one of three transmitters is equipped with independent antenna with circular direction (antennas are completed on the customer choice). Main peculiarity of the system is microprocessor, which analyses signals from antennas and gives a command to switch to receiving of signal of best quality.

In the base of operation lies the use of few remote receivers, so-called “carried” receivers, which switch between antennas. Many companies produce such facilities, but their working characteristics are not perfect. The reason is that switching from one antenna to another doesn’t guarantee increase of image quality and, more over, it can lead to that even minimal signal will totally disappear. For overcoming of all possible noises in DynaPix technology of quality of video signal detecting Quality Video Detect (QVD) is used. It consists of that the signal from all of the transmitters is constantly evaluated on maximum quality and transmitters switch automatically in lower-case advance pulse (about 15725 times/sec). The base of the technology is:

• scheme of detecting of video signal synchronization. In QVD technology is used switching of each synchronic video signal based on lower-case advance pulses;
• symmetrical architecture of transmitter. Outlet of demodulated signal from each transmitter is analyzed with the help of digital microprocessor. That allows choosing signal of maximum level with maximum accuracy;
• restoration of constant component. Use of QVD technology guarantees that during switching of transmitters the level of video signal is not going to change, and in other case that could lead to fluctuations in signal brightness;
• accurate indication of strength of received signal (RSSI) on each transmitter. In majority of cases transmitter with the highest level of RSSI is the facility with video signal of best quality.

DynaPix Triad allows to receive signals in frequency diapason of 2.0…2.5 GHz and can have 5…10 fixed frequencies. On the front panel of the system LED display of synchronization errors (on/off) , channel switcher, ten segment LED display for reflection of signal strength of each transmitter are situated.

DynaPix transmitter set on the camera

Preparing for operation and control of the DynaPix Triad system is not very complicated. DynaPix system is same appropriate for studio works as well as for out of studio filming. It can be used for news broadcasting from the place of event, studio production, and sports broadcasting, used in robot techniques, etc.

Let’s name few concrete examples of DynaPix Triad system operating. TV company organizes filming of football game. One of operators has to film near planes: commands standing, referees on the field, hot situations at the gates, etc. Agree that it would be much easier for him to run with the camera on which DynaPix transmitter is set with it weight of about 700 g, than to connect the base through the cable.

Here is another example. It is live air in the country, and operator has to go deeper in woods and mobile television unit cannot drive in there. It is impossible to deal here without DynaPix.

Besides it is possible to use the system during broadcasting or recording of big concerts, when it is impossible to throw the cable through the crowd standing in front of the stage.

So, the field of application of DynaPix system is rather wide and it can be used everywhere, where qualified wireless video signal transfer is required.

Material is presented by “D&K Corporation”