How well do you know your radio really?

What use is an F-call? So, you've got yourself a transceiver and it's all working well. You've read the manual more than a couple of times and you know your way around your kit. It's great to know how to operate your own radio and I've spoken to many hams who know their way around their own radio backwards. I remember one day speaking with an amateur and we were talking about how I could show a spectrum scope showing activity across a band. He lamented that his radio didn't have that functionality. I had a quick look through his system and activated the spectrum scope on his radio. A pleasant surprise for both. The opposite happened not long afterwards when another amateur was using my rig to listen to a remote station. He fiddled with some settings and magically the station appeared from out of the muck and we could hear it clearly. I asked him how he did that and after some hand-waving it transpired that there were some settings I knew nothing about - the radio which I'd known for many hours, read the manual backwards and so-on. It's been on my to-do list for a little while now, but I've just spent an enjoyable couple of hours sitting at my radio, re-reading parts of the manual, learning more about its operating parameters, how to set filters, turn on and off pre-amplifiers, change microphone equalisation and many other settings. How well do you know your radio - really? I'm Onno VK6FLAB