I'm researching automatic gain control (AGC) for my DIY 20m SSB transceiver. I found an excellent lecture on AGC on youtube:
It turns out that India has a program where they are posting lectures on engineering topics, very good lectures, from the Indian Institutes of Technology and Indian Institute of Science:http://www.youtube.com/user/nptelhrd
As for the AGC lecture, it is very practical, i can actually design circuits from this. Not all academic lectures cover both theory and then dive into details on how to implement what was discussed.
Many thanks to IIT Madras for posting this lecture on AGC.