The figure shows the antenna GP for four bands : 28 MHz , 14 MHz , 21 MHz and 7 MHz . The main antenna - mast has a height of 9.95 meters, it is usual GP antenna for a range of 7 and 21 MHz for the other two antennas GP she is still supporting mast. This antenna - mast is earthed at the connection point and the ground is connected to the counterweight to the 10.5 m long ( 7MHz ) , 5.20 m ( 14MHz ) , 3.5 m ( 21mgts ) , 2.45 m ( 28 MHz ) . and inclined at an angle of 135 degrees, so it turns out that the input impedance of the three bands GP antenna is 50 ohm, allowing you to connect without any problems to connect the coaxial cable of the same resistance. This is most effectively four band antenna operates GP is in the range of 21 MHz , as in this range for the longest antenna - 3/4L mast contains a wavelength range of the counterweights to improve alignment with the cable. In the range of 7 MHz antenna GP consistent color across a transformer in the rest of the condensers . The disadvantage of this antenna GP - is that its base should be at a height of about 7 meters (to allow the angle of 135 degrees). Advantages that the antenna can be grounded.