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.
Transmitters were operating on RF channels 21 and 29 and shared the same antenna system by means of a Rymsa cavity filter combiner. Combiner and patch panels are clearly visible in the picture. To save space, the combiner was ceiling mounted via Nexum’s custom designed carpentry.
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.