1. A half-wavelength radiator, fed at one end with a quarterwavelength section of open-wire line. The feed line can come away from the radiator at any angle, usually 90 degrees or more. The antenna was originally used aboard zeppelins; the entire system was dangled in flight and the feed line was collinear with the radiating element. The impedance at the feed point is high; the impedance at the transmitter end of the feed line is low. The antenna will operate satisfactorily at all harmonics of the design frequency. 2. A radiator that is an integral multiple of a half wavelength, fed with open-wire line of any length. A transmatch is employed at the transmitter and of the feed line. This arrangement is popular among radio amateurs. The primary advantage of this antenna is ease of installation; the main drawback is the fact that the feed line radiates to some extent because the system is not perfectly balanced.