You do seem to be right. It should not matter in theory, but it may be better for the one connected to the center (right on this image) to be up.
For vertical polarization, in theory it does not matter which way around you orient the antenna as long as it’s vertical. However in practice, you may get slightly better results by having the element connected to the center coax conductor pointing UP.
Weird that they don’t elaborate. I flipped it last night and it seemed marginally better this way, so maybe there is some truth to it. Take this with a truck load of salt as it wasn’t any sort of controlled experiment at all.
in your antenna, the outside of the coax makes up part of the radiating structure. The orientation of the elements in relationship to that coax will definitely change the radiation pattern, maybe for the better maybe for the worse.
putting ferrites around the coax right below the antenna feed point will make the antenna more symmetrical as it blocks RF currents traveling back down the outside of the shield.
You do seem to be right. It should not matter in theory, but it may be better for the one connected to the center (right on this image) to be up.
Source: https://www.rtl-sdr.com/using-our-new-dipole-antenna-kit/
Weird that they don’t elaborate. I flipped it last night and it seemed marginally better this way, so maybe there is some truth to it. Take this with a truck load of salt as it wasn’t any sort of controlled experiment at all.
in your antenna, the outside of the coax makes up part of the radiating structure. The orientation of the elements in relationship to that coax will definitely change the radiation pattern, maybe for the better maybe for the worse.
putting ferrites around the coax right below the antenna feed point will make the antenna more symmetrical as it blocks RF currents traveling back down the outside of the shield.
It has a choke on it, it’s a little blurry but you can see it. Should it be moved closer? I saw a comment on rtl-sdr’s blog suggesting it.