The Yagi-Uda Antenna - Yagi Antennas
Notice that the reflector and director are based on resonance not length of the element.
When using a 1/2 wl dipole or folded dipole the length is an electrical 1/2 wl or full wave length thus simple math can be used to make the length of the reflector and the directors.
If using a 5/8 then every element will have to be made to resonant on the frequency needed to be a reflector or director.
I said that just making the physical length of a reflector or director 5/8 wl plus or minus 5% would not work as all elements would need to be resonant with a matching network.
As far as the 1 or 2 dbd gain. Compared to what? a 1/2 wl dipole? the 5/8 wl might have .75 to 1 dbd gain over a 1/2 wl dipole.
If the dipole is horizontal then the dipole will have more gain than the 5/8 wl if it is vertical.
As BOB said a 1.5 wl which is working off the third harmonic of the fundamental frequency has been tried. It is called a 3/2 dipole. I have used them for the Hf bands and they do work well as the major lobes come off the end of the dipole at a 30 to 45 degree angle not in a figure 8 pattern as a typical dipole.
If the 5/8 wl yagi is feasible and works better than a 1/2 wl dipole feed yagi why are there not any produced and sold?
I can not detect a 1dbd difference in any of my receivers I have if you can that is an impressive receiver.
Not a pissing contest, just a good conversation
