Effectively this is an active antenna that uses a 555 chip or, in [Byon’s] case, a PIC chip to quickly shift between two receiving dipole antennas at either end of a shortened yardstick.

We have all seen Printed Circuit Board (PCB) antennas: those squiggly bits of traces on PCBs connected often to a Bluetooth, WiFi or other wireless communication chip. On modules like for the ...