Not always, amateur radio is the ability to set effective long wire antenna for the 3.5 and 7 MHz . If you want to install a wire antenna type inverted V and there is no place you can upgrade this antenna a bit , reduce the size of the antenna input of the extension coil . As can be seen from the figure below size wire antenna extending spools approximately equal to the size of half-wave dipole for 7 MHz . The mast antenna has a small height, which is approximately 7 meters, the lower ends of the antenna is at a height of approximately 1.5 meters from the ground . Also from the figure that the power antenna wire modernized type inverted V through the delta transformer via a coaxial cable with an impedance of 50 ohms ... 75 . For a more exact matching transceiver must have the tuner . Since this wire antenna significantly affects the properties of the soil ( container terminal ) , then after the installation requires careful tuning . When you set up a wire antenna to watch its resonance and SWR. Changing the resonance of 100 kHz to 3.5 MHz band can occur when the length of the segment b by 5 centimeters. If you still do not get the minimum SWR you can try to change the point of connection of the delta - the transformer. With this upgrade wire antenna type inverted V, the antenna in the range of 3.5 MHz to baseband . This antenna is useful in field conditions and in areas with limited space.