Antenna engineers like logarithmic terms, and we say this no-gain situation is 0 dBi (pronounced “zero dee bee eye”). Imagine a giant stellar sized mirror beside our sun. Imagine how it would change this energy distribution and give the sun directivity.
That type of antenna is normal for a Medium Wave AM antenna, not a VHF FM signal. In that case, the entire tower is a radiating antenna. Look here: Antenna Length calculations. ?? When I built a half watt FM transmitter for my sons to DJ on, I made a 5/8 vertical and had it at 30 feet.
Wire Antenna Length Calculator This calculator is also simple enough. It allows you to test the resonant frequency of the antenna for lowest SWR and zero reactance, and adjust the length to the exact frequency you want, in just one step, rather than a lengthy process of cut and try.
Aug 09, 2017 · My interest in making DIY 1/2 wave dipoles with the little PCBs I illustrated is related to the idea that it would be easy to connect antenna arms that are the relevant 1/4 wave length for some specific frequency within the 450MHz to 650MHz band.