Greg, KC2DWF, sent me this link to a really great web site about the AM broadcast station WLW (aka "The Nation's Station"). Brace yourselves guys, for we are now moving out of QRP land: The exciter on this baby is 50 kilowatts! The modulator could produce 400 kilowatts of AUDIO! The article is very well written, obviously done by an aficionado of high power RF. There are some great lines in there. Here is a sample: This brings up the real fun part of 1934 AM broadcasting - NO LIMITERS! WLW, like any big-time station at the time, gave the Full Monty: 100 per cent modulation. Now, radio textbooks always have cute little pictures of sine waves at 100%, but people don't talk in sine waves. They don't beat drums, play hillbilly music, or yodel in sine waves. If the studio asked the big rig for some outrageously asymmetrical upward modulation barely crossing zero at all, the DC-sucking beast said FEED ME and obliged - briefly. Voltmeters dipped at the power company, antenna current went haywire, cows felt funny tingles in odd places, and various shotgun-loud bangs and sparks filled the transmitter building.
Have fun, but don't get any QRO ideas...
Here's the link to the article:
http://www.ominous-valve.com/wlw.html
More info and pictures here:
http://www.oldradio.com/archives/stations/cinc/wlwpix.htm
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Hey, Bill. There's another one of those great names from the past: Blaw-Knox.
ReplyDeleteWhat beasts those towers are (many survive to this day). They look as though they could survive an nearby atomic blast, HA!
73.......Steve Smith WB6TNL
"Snort Rosin"
You get even more afraid when you find that german tabletop 15kW linear. It is really a table top +10kW linear.
ReplyDeleteLooking at it just screams "Build me a brother!"
(My station produces max 75W PEP at the moment, but that does not mean that I would not like to pump a kilowatt into my dipole from time to time) :P
Here's a video tour of WLW posted on YouTube by k7AGE
ReplyDeletehttp://www.youtube.com/watch?v=CbHjcwIoTiY