We've talked in the past about skywave propagation, but it's cool when you heard about real-world examples of it. Recently I've gotten several emails from "DX'ers" (Distant Reception enthusiasts) in Europe saying they've been able to hear Latino Public Radio on 1290AM all the way across the Atlantic!
We have put a temporary setup in place with a donated 30 watt transmitter on loan (with the antenna array's gain factor of 2.1, it's really more like 63 watts of Effective Radiated Power), and a special radio that's tuned to 102.7FM (there's a high-gain FM antenna on the rooftop tower) and puts out the composite signal directly into the new transmitter. This effectively makes 91.5 into a "repeater" of 102.7FM.
Air conditioning. Cool heaven for those who have it, blazing hell for those who don't. It didn't used to be terribly common in broadcast engineering, but it's become moreso in the last ten years. The reason is that, more and more, audio processors, RDS encoders, audio encoders/decoders, studio/transmitter links, remote control systems, and even the transmitters themselves, have all become increasingly "computer-like" with IC's, hard disk drives, power supplies, electrolytic capacitors and the like. All things that fail quickly when operated in temperatures above 80 or so, and the warmer it gets, the faster they fail!