Silicon Image Inc., a developer of high-bandwidth semiconductor and system solutions for mass markets, has purchased Tektronix signal sources and oscilloscopes for the first High-Definition Multimedia Interface authorized testing center in the US. HDMI provides an interface between audio/video source devices, such as set-top boxes, DVD players, A/V receivers and digital displays.   . . .   The Link Simulation and Training Division of L-3 Communications has awarded a contract to Zygo Corp. and Optical Research Associates to develop a helmet-mounted display for new and upgraded flight simulation systems used to train US armed forces pilots. The companies will deliver prototype helmets in 2004 that use high-resolution display and imaging concepts for combat-readiness training. The new units will resemble lightweight goggles that can be worn with pilots' helmets.   . . .   Pennsylvania Community and Economic Development Secretary Dennis Yablonsky today announced $7.48 million in funding by the Ben Franklin Technology Development Authority (BFTDA) to support Gov. Edward G. Rendell's technology-focused economic development strategy. The BFTDA is a state-funded network to foster technology innovation; it supports four Ben Franklin Technology Development centers in the state that identify promising technological ventures and provide them with technical assistance and capital.