I bought one 3 years ago at York from the vendor in the Purple Hall that sells them. Something like $110 - captured both color and sound and transmitted it to whatever TV the receiver was attached to.
About 75% of the time it transmitted a loud cracking buzz and ziggley lines - too annoying to watch, let alone enjoy. I worked with the vendor on several occasions trying every suggestion that he offered - nothing worked. I took it outside, I mounted the receiver on the ceiling in the middle of the same room as the camera, tried using the camera in different rooms in the house, hooked up the receiver to a different TV in a different room, etc.
I finally recorded a 20 minute session and sent it to the vendor - he admitted that he never saw anything like what was happening with mine. He had no further suggestions
Too bad - it was a toy that I wanted for a long time and was REALLY looking forward to having a LOT of fun with it. I was so looking forward to controlling my layout (using DCS) from my recliner in the game room by watching where the train was on my TV. I finally gave up and he refunded my money. Sad day.
- walt