Digital HF receiver

The paper describes an experimental digital receiver (tuner) for wideband applications in the HF-band. The output from the receiver is an undemodulated digitised signal with 750 kHz of useful bandwidth. The 5 MHz sampling frequency is generous compared to the bandwidth. This relaxes the demands on the analogue components and gives us the possibility of using baseband sampling without introducing aliasing distortion from the harmonic signals. Measurement shows a spurious free dynamic range of 80 dB. The low baseband sampling frequency enables us also to make use of an operational amplifier as the final drive amplifier for the A/D converter