Would you prefer an inverted V or a horizontal dipole antenna?

I started off with inverted V half wave-dipole antenna for 40m, mounted on a wooden stick on my terrace as my first antenna. Later I moved on to horizontal dipole antennas (actually ‘V’ due to sagging of feedpoint) mounted between tall coconut trees at my parents’ home. In case of antenna, ‘height is might’. Naturally, my ‘horizontal’ dipole performed better. Moreover, by that time I had migrated from VU2VWN QRP to 3 x 807 homebrew TX with 120W DC input. Now I am using a fan dipole for 40-10m mounted as inverted V and another inverted V at lower height for 80m. Now what are the expected features of both these mounting patterns of a half-wave dipole antenna? Inverted V is quite convenient if you have only one high mounting point like a mast on the terrace and two lower poles on the garden below.

Feedpoint impedance of a horizontal dipole is around 72 ohms, which is a bit more than the 50 ohms of the feedline coax and radio. In case of inverted V, as the ends are at a lower height, feedpoint impedance may drop to around 50 ohms, making it a better match for the coax. The feedpoint impedance also varies with angle that the antenna elements form at the apex. Sharper angles closer to the vertical line at the apex reduces the feedpoint impedance. Antenna ends closer to the ground also decreases the feedpoint impedance.

Pattern of radiation of both types of dipoles are perpendicular to the axis of the antenna. Yet in case of inverted V, as the limbs of the antenna are angled downward, the radiation pattern tends to become a little omnidirectional compared to a horizontal dipole. Inverted V dipole has a lower angle of radiation and is good working long distance (DX) stations. The low angle of radiation reaching the ionosphere reflects down at longer distance. Near vertical signals bounce back to a much shorter distance. This is especially true of horizontal dipoles mounted at low elevation compared to the wavelength of operation.

Ideally, the angle between the wires of the inverted V should be at least 90 degrees and preferably 120 degrees. But lack of suitable support points on the ground may necessitate compromised mounting with less than ideal angles at the apex. Anyway, that is better than having no antenna at all. So don’t hesitate to use a less than ideal angle if unavoidable. Though performance may be slightly lower, you can enjoy the wonderful hobby of amateur radio. Sloping wires of the dipole causes about 5% reduction in the resonant frequency for the given length of antenna elements. As in case of any wire dipole, it is better to start with a longer length and trim as needed for the most often used frequency by checking SWR and if available a NanoVNA. Reducing length can also be by folding back of the terminal end on itself, though it is not exactly equivalent to trimming. But folding back is reversible while trimming is not!

Another advantage of the central support in case of inverted V antenna is that it will not sag by the weight of the feedline coax and the balun and become a ‘V’ antenna as I had in olden days. Heavier low loss cables like RG213 can be used comfortably with an inverted V antenna. In case of horizontal dipoles, some use pulleys at the ends and hang down weights on the tie wire to counter the weight of the feedline and balun. In that way horizontal dipoles can be made really horizontal. To avoid accidental touching of antenna ends by humans or animals, lower ends of the inverted V dipoles should be at least 3m above the ground and well insulated.