disk shape revolving around tv tower

I was about 8 years old, my parents had taken us kids to my grandparents house for a family get together and to watch the chiefs game.  From the backyard you could see the stadium in the distance, it was dark out but a very clear sky.  
Everyone went out to watch the blimp over the stadium, after awhile everyone except me a my younger sister went back inside, we went around to the front of the house which faces east.  There are tv towers on the same hill my granparents live on, to the south we saw a group of lights slowly approaching, at first I thought it was the blimp but as it got closer I could tell that it wasnt. The body itself blended into the night sky, but it had what best looked like passenger windows on an airplane, but they were slowly revolving around the side of the object with a soft flourescent like light emitting from them. 
Without a sound it very slowly hovered around a tv tower that was no more than a 1/4 mile away, it had dropped down about 20 feet lower than the top of the tower, moved around it and then stopped for a second and then headed back in the direction it came moving very slow and quiet. 
I had dismissed it thinking I was too young to know what I was looking at and as I got older I dismissed it thinking i hadnt seen it at all but merely dreamt it, then at a recent family gathering my sister asked me if I remembered seeing the ufo when were kids, which I had figured that since she was four years younger than me, there would be no way she would remember it, but she described the experience exactly as I had remembered. The object seemed to be about 30 feet long and the way the lights moved around it suggested it was saucer shaped.
Witness indicates that the date of the incident is approximate.  PD