M6SIG

Just watch the whole ep. I notice you guys forgot to put a matching resistor at the end of the collina. Since you want a 75 0hm antenna, which is good for receiving only, you need to put a 75 ohm resistor between the center conductor and the outer conductor at the end of the last element. After all, it is a very good ep!

I notice there are some confusion in the Ep. The "ring" on the yagi is actually a folded dipole. The purpose of a folded dipole in a yagi is to match the antenna. In theory, the impedance decrease as the number of directional element increase. Because we need a 50 ohm antenna, and we want a lot of directional elements, so that we need a folded dipole there.

Hi all, Here is a snapshot of a GNU RADIO project I built in last Oct. It is for demonstrate the difference between NBFM, AM, USB and LSB signal in FFT and waterfall to my students in the Amateur Radio course. The flow graph as well. I used a RTL-SDR to receive a local WBFM signal then demodulate it and then modulate the audio again then mix them together and then output. If you want to transmit a audio, just delete some part of my flow graph then feed into a hardware source and enjoy~