Underwater television installation "PTU-5" was produced since 1956. An underwater television installation is used when inspecting hydraulic structures, studying flora and fauna, lifting wrecks, fishing, etc. The installation package includes a transmitting television camera placed in a hermetic casing (bathysphere), on the sides of which two lamps are fixed and control and adjustment equipment units, which include amplification and image signaling units, a power supply unit, a switch-on unit and an additional video monitor. The amplification and shaping unit has a video control device with a 13LK2B type kinescope, thanks to which the image quality is controlled. On the front panel of this unit are located the remote controls for the mode of operation of the transmitting tube and the optical head, as well as all the other controls. The power supply contains rectifiers, sweepers and a sync generator. For synchronization, in the PTU-5 installation, not a sawtooth voltage is used, but a sinusoidal voltage. This has dramatically reduced the size and weight of the installation, as well as making it more economical. The switch-on unit serves to supply electrical energy to underwater lamps. For simultaneous viewing of the image by several observers, an additional video monitor with a 35LK2B kinescope can be connected to the installation. For convenience of operation, a remote-controlled flap can be connected to a video monitoring device, attributable to a distance of up to 5 m, the optical focusing head of the optics, diaphragm and changing the viewing angle and current of the transmitting tube beam. All blocks of control and adjustment equipment are made in the form of portable packs of suitcase type. The television camera uses the most sensitive of all transmitting tubes - the superartikon LI-17. With this handset, the normal operation of the installation is ensured in a daytime clear to the code without highlighting the transmitted objects.When working at night or overcast weather, it is necessary to use lamps to illuminate the observed object. For ease of operation in a television camera, an electronic zooming system is used, which allows almost instantly, without a loss of focus, to change the angle of view of the camera from 60 ° to 30 °. The main technical data of the installation: Decomposition is interlaced into 625 lines at 25 frames per second. Illumination on the photocathode of the tube LI-17 0.2 ... 10 lx. Changing the angle of view, aperture and focusing optics remote. The length of the chamber cable is up to 350 m. The length of the cable connecting the additional video monitoring device with the block of amplification and shaping is up to 100 m. The ambient temperature is from 25 to -40 ° C. The power consumption is not more than 500 W. Power supply from AC 220 V, 50 Hz. Camera dimensions excluding fixtures: diameter 222 mm, length 745 mm. The dimensions of the gain and shaping unit and the power unit are 179x328x418 mm. The dimensions of the additional video monitor are 390x376x540 mm.