1/4 wave or 5/8?

[NC1]

To further understand how you receive signals in the shadow of a hillside that you think would be blocked, below is an excellent article and easy to understand. Knife edge diffraction is also one of the questions you study before passing an Amateur Radio exam. It was on mine.

Radio Wave Diffraction | E/M Wave Diffraction | Electronics Notes

 

[Ubbe]

I'm thinking that the added gain of a 5/8 would make the frequency bandwidth somewhat the same as a 1/4 where their gain are the same.

I might, but for transmitting applications, the reflected power starts to go up pretty quick when you get away from the tuned frequency of the 5/8th's wave.

If you look at the highest frequency 174MHz for the 1/4 it is a 2.2:1 SWR and for the 5/8 it's 3.5:1
It's a 13% loss versus 30% which is a 17% difference and a 20% difference are 0.8dB

I still believe that the gain of the 5/8 will be more than 0.8dB at center frequency compared to the 1/4 wave antenna which will compensate for the 0.8dB difference in loss of signal way out of the usuable frequency range, if the direction loob of the 5/8 isn't pointing more straight up in the sky than the 1/4 will do.

/Ubbe