I've been experimenting with different ways of having 5-10 different old school systems on one TV with some type of switching. It's easy with AV cables (see my setup on www.brokenclavicle.com/arcade - the switcher is in the 9th and 10th pictures).
I tried something similar with the older systems that use RF cables such as the 2600 and the Odyssey2. The output is a simple RF switch into one of those connector gizmos like this:
In theory, at least in my mind, this should work. However, the picture quality is crappy. I've tried similar switch boxes and different cables with varying, but dismal results.
The only thing that works rather well, is this 2 position switch:
I got one on Ebay a while back.
However, this only allows switching between two systems. Anyone know of an easy way to get to switch between 10 systems?