31. On the ground, to obtain directional radio beams with a well-defined navigable course, crossed loop antennas were used initially. 32. Using conventional radio receivers and loop antennas for direction finding, radio operators could determine which of the signals was false. 33. :: Yep, AM radio needs either a ( relatively ) bulky Loop antenna , or a * very * long wire. 34. This has practical advantages for makeshift or home construction and may be found in resonant loop antennas or crystal radios. 35. In amateur radio, loop antennas are often used for low profile operating where larger antennas would be inconvenient, unsightly, or banned. 36. In this system the loop antenna is replaced with a single square-shaped ferrite core, with loops wound around two perpendicular sides. 37. The Adcock antenna is an arrangement of four monopole masts that act as two virtual loop antennas arranged at right angles. 38. For non directional portable use, a short vertical antenna or small small loop antennas are tuned with parallel capacitors for this purpose. 39. Rotating the sense coil in the field coils has the same output as rotating the entire loop antenna in the original field. 40. This was accomplished by rotating a loop antenna to maximise ( or minimise ) the signal, thus " pointing " to the storm.
