Bernard presented on small magnetic loop antennas at the June meeting. Bernard has been working on these for many years, and the main message was -They work very well but must be made very carefully and you need to accept a number of limitations.
The main limitation is the very small bandwidth, followed by the high level of care required in designing and making them. A key issue is loop resistance. Bernard makes his loops from 1 inch copper pipe and to reduce the resistance from the joins, uses 4 x 90 deg angles, carefully silver soldered. His loop is a square!