Support my work [ Ссылка ]
You never know what you will get from China. Good stuff or chinesium? A little bit of this, a little bit of that. Just like this 868MHz antenna, I got from Aliexpress. In theory, everything looks like it should look like. Sleeved dipole, nothing fancy. But then it turned out that this is not regular sleeved halfwave dipole. It's something else.
Luckily, with a help of my NS1201SA VNA (Vector Network Analyzer), aka antenna VSWR meter, I was able to make a few experiments with it and tune to exact frequency I needed.
So, is there an antenna guru that can tell us what this extra brass sleeve was doing? Bug or a feature? Wouldn't it just be simple to cut active element instead of adding this part? To change impedance or radiation pattern? Or both?
