If you have experienced software defined radio (SDR) using the ubiquitous RTL SDR dongles, you are missing out on half of it. While those SDRs are inexpensive, they only receive. The next step is to transmit. [Corrosive] shows how he uses DATV Express along with a Lime SDR or a Pluto (the evaluation device from Analog Devices) to transmit video. He shows how to set it all up in the context of ham radio. An earlier video shows how to receive the signal using an SDR and some Windows software. The receiver will work with an RTL SDR or a HackRF board, too. You can see both videos, below.
The DATV Express software has plenty of options and since SDR if frequency agile, you ought to be able to use this on any frequency (within the SDR range) that you are allowed to use. At the end, he mentions that to really put these on the air you will want a filter and amplifier since the output is a bit raw and low powered.
If you are old enough to remember when a TV transmitter was a big box full of circuitry, seeing video pour out of a little circuit board is pretty amazing. What’s more, is that on transmit and receive you can do an impressive amount of processing in software that would have been very advanced using traditional hardware.