Case History: Broadcasting

4Mux 2,5Kw rms installation in the RaiWay’s Salento-Turrisi site

During Italian ATV switch-off in Puglia (a beautiful southern Italian region), Nexum installed a large DVB-T system based on 5 x 5 kW RF output power transmitters. Final Customer was Rai Way and transmitting site was known as Turrisi. TV transmitters were liquid cooled and manufactured by Plisch while the cavity combiner was supplied by COM-TECH. Heat dissipated by the transmitters was brought to the external mounted heat exchangers via a complex system of redundant stainless steel tubes. Also heat exchangers are redundant (5 + 1). Despite the time schedule was challenging, the system was commissioned on time avoiding any user’s disruption.

4Mux 5Kw rms installation in RaiWay’s Martina Franca site

On behalf of Syes srl we have installed 4 Mux Raiway with output power equal to 5Kw rms. The equipment is in Syes technology with liquid cooling. On Syes project we have taken care of all aspects of the installation including the masonry works. Given the high power involved, it was necessary to use rigid 3-inch lines. The cooling system was realized by positioning the heat exchangers outside protected by a proper protection cage.

Massive ATV system at Manila – MCI & Solar (broadcaster)

In cooperation with leading broadcasting equipment manufacturer Screen Service, which supplied the equipment, Nexum installed and commissioned a MASSIVE ATV (digital TV ready) transmitting system: 60 + 60 kW RF (!!) for the local broadcaster Solar (through MCI which was the local distributor). Once performed the site survey, Nexum realized the site engineering, designed and supplied the custom carpentry and the installation materials, managed the civil works, installed and commissioned the system and finally put it on air. With the transmitting system on air, an extensive technical training (focusing ordinary & extraordinary maintenance) was also provided. The transmitting system is based on 2 transmitters, each one capable of 60 kW RF, combined by Rymsa cavity filters. All coaxial rigid lines were 50/120″. Transmitting system were liquid cooled and the heat dissipated outside the telecom room by eight redundant heat exchangers.
Final commissioning of a transmitting system with a so high output power was a crucial point because the system’s VSWR must be extremely high and reflected power as low as possible. Also a small amount of reflected power can easily damage the internal devices. Output power were increased slowly and after every step all measurements were performed.