Performance of simple diversity antenna arrangements in HF data systems

The efficacy of diversity reception in reducing the effects of fading on HF circuits has been recognized for decades. It is particularly useful in HF data systems, where the improvement in bit error rate afforded by diversity can often make the difference between success and failure in a data link. Yet it seems that diversity techniques are often overlooked in many instances where they could profitably be employed. The author attempts to redress this situation by providing the results of a series of on-air measurements of the performance of a low-speed HF data link. Results of bit error rate measurements for nondiversity operation are compared to those for inband frequency diversity, and these in turn are compared to those of simple and expedient antenna diversity arrangements. A brief review is included of results from the literature on HF diversity measurements