I am considering building a FAN DIPOLE for the following frequencies: 10 MHz, 18 MHz. 24 MHz. and 50 MHz.
As you tune (cut) dipole (1/2-wave) wire lengths, be very AWARE of TWO 3/2-wavelengths in your antenna.
30 meters (10.1 MHz) ---> 3/2-wave at 30.3 MHz, just outside 10 meters
17 meters (18.068 MHz) ---> 3/2-wave at 54.204 MHz, just outside 6 metersThe 30 meters (10.1 MHz) also presents a 5/2-wave at 50.5 MHz (6 meters), which you may not detect.
You can easily mistake the wrong tuning point, if you are not watching OR using inaccurate test equipment.