I love the stuff from the 70's seeing that's when I got in it makes sense. I really enjoyed reading the review of the Mark IV. It brought back memories of all that was going on with CB at the time. It wasn't just adding channels, there was so much talk about modulation being cut back and that the radios just wouldn't talk very well. Also it was going to be illegal to sell a radio that didn't have 40 channels. So everyone was waiting to hear one on the air and wow did they sound as good as ever.