 |
| The picture above is a diagram of the old standby CLASSIC antennas... the Dipole and the Inverted "V" antennas. They are shown superimposed on each other in the above representative drawing. The BLUE colored line is the dipole configuration. The COPPER colored line is the inverted vee configuration. The Inverted-V is basically a straight dipole broadband antenna with high gain that requires a little less space than the straight dipole and requires only one long mast at the center. The base, or bottom of the 'V' is connected to the top of the mast. The end of one arm of the Inverted-V is connected to ground via a terminating resistance, while the other end of the second arm is connected to the antenna feeder. The Inverted-V antenna is an excellent antenna for static locations. On flat ground the Inverted-V antenna radiates mainly surface waves, but can be used to generate space wave if erected on a hill. Both antennas can be constructed just about anywhere using any type of wire you may have and can be used with 50-75 ohm coax or open wire ladder line and an antenna tuner. The use of an RF choke balun is highly recommended. Most antenna critics agree there is little difference in the performance of either the Inverted-V and the straight dipole. The largest difference between the two antennas is the length of wire needed. Inverted-V's usually require about a 5% shorter wire length per leg than the straight dipole. You could use the calculator to build a 75 meter dipole and then calculate an Inverted-V for other bands suspended under it from the same support and feed both with the same line to your transmitter. A little experimentation may be required for adjustment of the Standing Wave Ration (SWR), tuning the 75 meter dipole first for lowest SWR and then the Inverted-V. |
| LENGTH CONVERSION FACTORS | ||
| CONVERT FROM | TO | MULTIPLY BY |
| mile (US Statute) | kilometer (km) | 1.609347 |
| inch (in) | millimeter (mm) | 25.4 * |
| inch (in) | centimeter (cm) | 2.54 * |
| inch (in) | meter (m) | 0.0254 * |
| foot (ft) | meter (m) | 0.3048 * |
| yard (yd) | meter (m) | 0.9144 * |
