The evaluation of 500 kW shortwave transmitters at the Voice of America

The Voice of America (VOA) has initiated a major program to modernize and expand its worldwide broadcast system. The program includes the procurement of 500-kW shortwave transmitters both for new stations and as replacements for aging and less efficient equipment in existing facilities. To develop and verify a specification for new transmitters, four currently available 500-kW transmitters were purchased from separate vendors for evaluation at the VOA facility in Greenville, North Carolina. The intent of this off-the-shelf approach was to ensure a proper level of technical rigor in the specification without unduly restricting competition among suppliers. The evaluation focused on a variety of factors including installation, performance, operability, and maintainability. The procedures followed during the evaluation are described and some of the salient findings are presented