The K9AY is terminated loop. It consists of a wire loop of any convenient shape (diamond, delta, etc), hung from a single support and with a ground rod at the bottom. A 9:1 impedance-matching transformer is connected from one end of the loop to the ground and terminating resistor is connected the other end of the loop to the ground. This antenna is directional. Favoring signals are arriving from the feed point end. You can also change the antenna far field by changing RLOAD (RTERM) of the loop.
Main functions:
Price: TBD