When I use my sdrs for digital mode decoding I don't need a knob, however, when I want to listen to voice modes and cruise the band via the sdr rigs I'm frustrated by the lack of same. I've been pestering a manufacturer of low cost radio doodads to roll out a cheap but cheerfull tuning knob and they're looking it over. There's a few vids on youtoob where a guy took apart a mice and used its optoencoder to make a tuning knob, so it can be done by the home builder. We should make one for Al that has penguin stickers on it.