The Voice of America (VOA) broadcasts almost 700 hours of programming on shortwave and medium wave to an estimated audience of 86 million each week. Broadcasting in 53 languages, including English, VOA reaches a large cross-section of the world's populations who tune to the international airwaves for news and information. In addition, VOA provides programming in 46 languages to more than 1,100 AM, FM, and cable "affiliated" stations around the world. These "affiliated" stations greatly expand VOA's audience beyond the 93 million tuning in on shortwave and medium wave direct broadcast frequencies. (http://www.voa.gov)
Droit Technologies provided consultation on Voice of America design of a radio stations on the Island of Sao Tome, Kuwait, and Island of Tinian in the Northern Mariana Islands.
Droit Technologies provided consultation to The BARC Group (now Hanson Engineers) for system designs which included PABX, Intercom, Paging, Master Clock, Control room shielding, and Filter room specification and design. Government security system integration. Assisted other Architects and Engineering specialties with systems integration issues.
Sao Tome was a unique challenge in that the island had little in the way of facilities to support the site. Power was supplied with generators and fuel for the generators had to be shipped in. There is no deep water docking available, so pumping stations and hoses to the fuel ship needed to be designed. The fuel ships would only arrive a few times a year, so large tanks had to be built for storage with spill containment features.
The main transmitter was a 600KW AM station with a frequency at approximately 1 MHz. There were also 5 other 250 & 100 KW transmitters in the HF band. (ABB/Thomcast). The AM transmitter raised problems for the possibility of arching at the fuel depot and the electronics of the station. Grounding and filtering became a major cost to the station.
For security, the whole site was fenced and cameras positioned around the perimeter. If the site would come under attack (from the native population), the kitchen was designed as the fallback . The Buildings were Butler metal structures with the kitchen area made special within, being formed from 8 inch concrete block and steel doors. The kitchen was equipped with SSB radio for SOS and camera control to see what was happening.
The control room was another special area within the building completely shielded with sheet steel, special glass windows , HVAC honeycomb filters, and lighting to prevent self interference from the transmitters. All control lines and power had to be filtered entering this space, or inherently immune (fiber optics) and run in steel conduit.
Lightning protection was also a major consideration. An aerial system was designed IAW NFPA 78 plus bare conductors running above all underground conduits between the buildings and lightning suppressors for power, telephone, fire and control signals at each building entrance. Ground rings around the buildings with all re-bar and structural steel grounded to it.
The control room had special grounding, an equipotential grid of 2" copper straps buried in the concrete floor with copper pad protrusions for equipment cabinet connection points.
The whole site had to provide interface connection points so that remote monitoring and control could be done by the VOA via satellite from Washington.
Kuwait had a functional VOA station before the Gulf War. To keep the station from being used by the Iraqis, it was blown to pieces and mined by the US. SHBC (Sayed Hamid Behbehani Co.) was awarded the contract for the new station and The BARC Group provided consultation. Except for the demolition plan, the design for Kuwait was almost a cookie cutter from Sao Tome. Kuwait had facilities for power, so only emergency generators were designed. Kuwait is strategically located for VOA transmissions, so buildings were designed so that expansion was possible.
Terrorists threats were a real possibility, so concrete ditches around the perimeter of the site prior to reaching the fencing were installed to thwart car bombers. The entrance to the site had a special gate that would have a steel panel rise up from the roadway that would stop a 2 ton truck traveling at 55 mph. The fencing had strain cabling and trip sensitive devices to detect climbing or breaking the fence.
Tinian was very similar also to Sao Tome with requirements for generators for primary power, special waste treatment, and a fresh water well. Tinian was a battle site during WWII and so there were archaeological concerns for remains. Typhoons required higher construction standards. The brown tree snake which kills all of the native bird species on the surrounding islands and was known to hitch a ride on cargo vessels was another concern. The VOA wanted to use 2.5MW generators for this project, but they were too large. Instead The BARC Group was able to convince the VOA to sell them to Tinian as a follow on project power plant.
Adventist World Radio - Argenta Italy About 50 kilometers east of Bologna. The work for the VOA built a reputation for HF radio broacast stations and led to the design of the Adventist World Radio (AWR) Superstation. The station features several steerable curtain antennas and a rotateable log periodic antenna. The station would have had a potential listening audience in 47 countries of the Middle East, North Africa, and Indo-Asia. The very restrictive "environmental" laws, that specify very low limits of electro-magnetic field (much more restrictive than the FCC in the USA) around transmitters have kept the station from being built, as of October 2002.
