This paper describes a transmission/reception (transceiver) system for the 456MHz - 459MHz band, which allows data communication between a ground station and an unmanned airborne vehicle. The transceiver makes use of quadrature frequency translation techniques, coherent indirect methods for signal generation and supports input signals with several types of modulation. The intermodulation products harmonics and spurious signals are 60dB below the carrier for an output power of 6dBm. The receiver has a sensitivity of -110dBm, a dynamic range of 80dB and an image rejection better than 28dB. The central frequency and the tune steps (100kHz) are digitally controlled by a PLL-based synthesizer. The transceiver draws 500mA from a ±12V supply. These characteristics were found to be good enough for the application referred above