K7AGE posts video of WLW's 1932 500,000 Watt AM transmitter

[video=youtube;CbHjcwIoTiY]http://www.youtube.com/watch?v=CbHjcwIoTiY[/video]

While In Dayton Oh at Hamvention 2013 I attended a tour of the WLW AM broadcast transmitter facility located in Mason Ohio. WLW has kept a major piece of broadcasting history alive by keeping much of the old high power transmitter intact.


Back in 1932 WLW increased their power from 50,000 watts to 500,000 watts. They were the only AM broadcasting station in America ever to operate at 500,000 watts. Much of the old transmitter still exists. It is really a high power amplifier with a high level modulator (360,000 watts). The amplifier was driven from their existing 50,000 watt Western Electric transmitter. The system used 20 100,000 watts tubes ($1,600 each in 1932) that required water cooling that used a cooling pond located outside the station. Tons, and tons, of hardware was required to achieve the 10 dB gain.


Before the 500 KW went on the air, WLW installed a Blaw Knox vertical radiator, or as we say today a vertical antenna. Back in those days a horizontal wire flat top antenna supported by two towers was common. Photos in the video show the impressive antenna farm at WLW.


The engineering was state of the art pushing the 1930s technology to achieve 500,000 watts. Operating the transmitter required a team of many engineers to bring it to life and control it while it was on the air. A simple ON-OFF switch did not exist!


Enjoy the tour of the facility and the history of this high power station. Thanks to Jay, Geoff, and Ted of WLW for hosting the tour.


I will soon post another video the covers the collection of 50,000 watt transmitters that are also in the same building.


To learn more about this transmitter's history, please visit these sites.


Randy


Jim Hawkin's WLW page:
http://hawkins.pair.com/wlw.shtml


History of WLW, Cincinnati:
http://jeff560.tripod.com/wlw.html


WLW's Big Arse Transmitter:
http://www.ominous-valve.com/wlw.html


Wikipedia:
http://en.wikipedia.org/wiki/WLW


WLW - A "Super" Station Tour:
http://www.oldradio.com/archives/stations/cinc/wlwpix.htm


Not Just a Sound: the Story of WLW:
http://www.broadcasting101.ws/wlw-1.htm

 

Wow. Thank you for posting this. It was very interesting and educational. One can only imagine what it would have been like to have the opportunity to work on equipment such as this. I started watching the video and was so enthralled that I missed my departure time for an appointment.

 

Meet K7AGE on HamRadioNow

Randy also sat down with Jeff & me for a HAMRADIONOW interview, which I finally got edited and just posted at our web site. Get to know Randy a little better! And thanks, Randy! Good job on the video...

73,
Gary KN4AQ
HAMRADIONOW.TV

 

WOW. I would like to see the Bird Wattmeter!

About 1947 I wrote a commissioned piece on Nathan Stubblefield (one of the claimed inventors of radio) for WLW, but could not receive it in Ky so don't know if it was aired.

TOM K8ERV Montrose Colo

 

That is impressive.
Thank You for posting that, it was fun to watch.

 

I believe some on "Da'Bowl" are running more than that? Awesome video. Still listen to WLW nightly.

 

Thanks Randy, I will take one

 

Shame to think all that hardware ended up in the hands of some Chicken Bander.

 

Just imagine building something like that the ingenuity involved the creativity! would love to know what the total project cost was and what that would amount to in todays dollars.

 

Thanks, this is much appreciated.

I've read that WLW was routinely heard in Europe during its 500 kW run. In a way it's a shame that it could not continue. World's Largest Wireless.

 

It's interesting but, at least a couple of dB down from the most powerful transmitter I've seen -- NLK, US Naval Radio Station, Oso, WA (Jim Creek).

When I saw it in the late 70s, NLK was running 1296A into 0.456Ω (765.9 KW) at 18 to 26 KHz (VLF). I was told by the tour guide that they've had it running as high a 2 MW output but they typically run at around 1 MW.

There are two transmitters (each contains six 4CW250000 tubes). Each tube runs 50 gl/min of cooling water. The transmitter house is alongside Jim Creek, with a heat exchanger for cooling. The tour guide said, when running the transmitter at maximum, Jim Creek is 1° warmer downstream.

The transmitters are combined in the 80'x80'x80' copper-clad antenna tuning room. There are two 12' diameter variometers in the antenna tuning room, driven by geared-down 5-hp 3-phase motors. LARGE knife switches inside each PA room accomplish plate tuning.

The antenna system is comprised of six runs of 750 MCM stranded copperclad wirerope between two mountains above the transmitter house. Each span uses four 4' long ribbed "dog bone" strain insulators at each end.

 

When I worked at KAAY (50KW) AM 1090 (1975-78) one of our senior engineers had been employed by
WLW. He mentioned that to transport various components of the 500 KW transmitter, a special 'rail line siding' had to be constructed to the transmitter site !!
Amazing video...
Thanks

 

Now let's see.... wonder if that thing could be tuned up for 20 meters..... nah!

 

But,...What if ??? OMGosh

 

It must have been a living breathing machine when it was running.