The early days of radio are just as fascinating with plenty of big electronics for transmitters. Droitwich the BBC's main LW transmitter is 500kW and still uses some of the old, water cooled valves. Thanks to the last round of govt budget cuts the transmitter won't last beyond the last stock of those valves.
If you want to see that sort of thing in the SF Bay Area, visit the Marine Radio Historical Society in Marin.[1] They have a big ship-to-shore station, built on Federal land a century ago and turned over to the Park Service when it shut down.
They operate many of the transmitters each weekend. They applied to the FCC for a commercial coast station license, probably the last one, and got it.
So they can send at quite high power. They talk to museum ships around the world.
See here for some background of their early days and photos : http://www.bbceng.info/Operations/transmitter_ops/Reminiscen...
No glow from the mercury rectifiers though - they're steel cased thanks to being 600kW