The antenna you depicted is a monopole, and I forgot to add, that if one varies the length of the radiator, the take off angle (and conversely the receiving signal angle) will vary too.
If too short a radiator, the coverage will also be reduced.
This happens a lot with MF broadcasters using this sort of antenna, but the "radial" system they use is at a 90ยบ angle relative to the radiatior, and are burried in the ground, typically 120 of them, and almost as long as the vertical element itself.
For instance, a 1 kW tx fed to a half wave monopole will have a larger coverage than the same tx fed to a 1/4 wavelength monopole.
Carlos this antenna is being used for the FM broadcast band.
I used the program that that image came from which is n2imf calculator using the N2IMF Antenna.exe antenna calculator to determine the radiator length and I am using 4 radials angled at 45 degrees.
I just wanted to know if feeding this antenna with 50 Ohm coax required any type of BALUN transformer.
I have the ground side of the transmission line grounded to a rod buried 3 feet in the ground. The radiator and radials have no physical connection to each other from the antenna to the transmitter.
No, you are quite correct, MF stands for medium freq. <> M.Wave. I rarely use abbreviations such as LW, MW, SW; I prefer the ones referring to freq. rather than wavelength.
And if there's something I particularly hate is the use of the terms "AM" & "FM" being applied to freqs. or waves.