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Capacitive adjustment of coupling between transmitter and impedance. Adjusted for minimum SWR.
Selects inductance for matching. DIRECT position bypasses circuitry.
Calibrates the SWR meter for accurate readings by adjusting meter deflection.
Adjusts coupling between antenna feedline and impedance presented by the BAND switch inductor.
Selects one of three coax-fed antennas or a single wire antenna for matching.
Selects meter sensitivity for power and calibrates SWR measurement.
Reads output power on three scales: 25W, 250W, and 500W.
Provides accurate SWR measurement when calibrated for adjusting controls.
Three female UHF-type connectors for coaxial feedlines or dummy loads.
Threaded terminal for single-wire antennas like the "Windom" type.
Connects to good earth ground for stray currents and RF reduction.
UHF receptacle for connection between FC-902 and transmitter/transceiver.
Emphasizes not exceeding maximum time limits during tune-up, especially at full power.
Shack matching doesn't affect losses on the coaxial line to the antenna.
FC-902 ensures 50 ohm load for protection against high SWR.
Suggests recording TUNE/LOAD positions for specific antennas for quick reference.
Capacitive adjustment of coupling between transmitter and impedance. Adjusted for minimum SWR.
Selects inductance for matching. DIRECT position bypasses circuitry.
Calibrates the SWR meter for accurate readings by adjusting meter deflection.
Adjusts coupling between antenna feedline and impedance presented by the BAND switch inductor.
Selects one of three coax-fed antennas or a single wire antenna for matching.
Selects meter sensitivity for power and calibrates SWR measurement.
Reads output power on three scales: 25W, 250W, and 500W.
Provides accurate SWR measurement when calibrated for adjusting controls.
Three female UHF-type connectors for coaxial feedlines or dummy loads.
Threaded terminal for single-wire antennas like the "Windom" type.
Connects to good earth ground for stray currents and RF reduction.
UHF receptacle for connection between FC-902 and transmitter/transceiver.
Emphasizes not exceeding maximum time limits during tune-up, especially at full power.
Shack matching doesn't affect losses on the coaxial line to the antenna.
FC-902 ensures 50 ohm load for protection against high SWR.
Suggests recording TUNE/LOAD positions for specific antennas for quick reference.
The Yaesu FC-902 is an antenna coupler designed for low and medium power applications across the HF amateur bands, specifically from 160 through 10 meters. Its primary function is to minimize the adverse effects of high Standing Wave Ratio (SWR) on coaxial or wire antennas, which can cause difficulties in tuning a transmitter designed to operate into a resistive 50-ohm load. By providing a proper match, the FC-902 ensures that the transmitter "sees" the resistive termination it was designed for, thereby optimizing performance and protecting the transmitter.
The FC-902 acts as an impedance matching device, allowing a transmitter to efficiently deliver power to an antenna system even when the antenna's impedance is not a perfect 50 ohms. It achieves this through a combination of adjustable inductive and capacitive elements. The inherent selectivity of its matching circuitry also helps to attenuate harmonics, which can reduce harmonic-related Television Interference (TVI) or out-of-band emissions.
The FC-902 features a user-friendly front panel with several controls for precise antenna tuning and monitoring:
The Yaesu FC-902 is a robust and versatile antenna coupler designed to optimize the performance of HF amateur radio stations by providing efficient impedance matching and SWR reduction, thereby protecting the transmitter and enhancing signal quality.
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