Gin had figured that much. If not just the Doctor, but also his rival had ways to send messages over the same system, surely others could too. The other part, causing the radios to find the right spot and turn on at the right moment, apparently would be more difficult. If they had to, they could just inform the patients ahead of time to have them on and focused on the right place to receive the message, couldn't they?

"Ara..." he sighed, though he kept his smile on. "Sounds complicated. Y'up to th' task? If y'let me know what kinda things y'need, I'll see that y'get 'em."