A Better HF SDR Than RTL-SDR?

The idea is simple: build a low-cost, purpose-built HF receiver around a cheap high-speed ADC instead of repurposing an RTL-SDR. An RTL-SDR is an excellent general-purpose radio tool, but it was not designed as a high-dynamic-range HF receiver. A direct-sampling design with proper HF preselection, controlled gain, a stable sampling clock and FPGA-based digital down-conversion should make a more…