Shamas,
You're giving away your age!
Welcome back and welcome to RCU. Usually, a flying field will block some frequencies from being used because something in the local area interferes with those frequencies often enough
to cause problems. Back in the day, there wasn't anywhere near as much technology polluting the airwaves that would cause problems. Now with cell phones, cordless phones, walkie-talkies,
ham radios and such, it's become a real congestion problem. Heck, I bet that even a slightly out-of-whack garage door opener might just cause some interference.
Anywho, it shouldn't take you long to get back into the swing of things and tell us what you think of all the new gear out there for this hobby, (sport?).

Jesse