One of the great things about radio is its portability. Take it to the beach, in your boat, on a train. Take it just about anywhere. What's changed over the years is how easy it is to do that. Nowadays we take the portability of radio for granted, as we stuff a smart phone with a built-in FM tuner in our pocket and head out the door. It wasn't always that easy. This month's Found in the Attic examines suitcase radios, in particular the Zenith 6G601D Universal.