You walk through the door. There is nothing interesting in there except for a man who will give the expansion card for your radio.
Chat with our AI personalities
Do you mean the Power Plant? Are you looking for the way to activate your radio in Kanto? That can be done at the Power Plant.
cheat
you go to the Kanto radio tower in lavender town
you have to go to the old ghost tower, east of vermillion city, it is now a radio tower and they will give you a Kanto radio chip for your pokegear.
You can't.