In this case what is a good SDR device that does TX? The one in the article does only RX
In this case what is a good SDR device that does TX? The one in the article does only RX
The hackRF is a popular one. If you want to do anything at range, note that you'll need an RF amplifier and an antenna.
Also note that TX is heavily regulated, and you should get licenced before you start blasting.
> Is there a very low bandwith equivalent of Internet via SDR?
There's open source software to build your own LTE tower using an SDR. That's not really low bandwidth, though...
Packet radio is done with amateur radio. There is both VHF/UHF ones that use normal radios, and 2.4GHz ones which usually use Wifi with dishes. There aren't BBSes because there isn't much point with Internet, and there isn't much point to Internet access when have mobile. Plus, it isn't allowed to provide non-amateur Internet access.
These days packet is boring as hell, nobody chats anymore. It's just aprs position messages that nobody bothers to look at :(