The AM Forum

There is "heavy metal," then there is HEAVY METAL -- all 500 kW. of it at the old WLW.

https://www.youtube.com/watch?v=CbHjcwIoTiY (https://www.youtube.com/watch?v=CbHjcwIoTiY)

Bob - NE

The FCC will never allow that much power again. And who has the money now to operate 500kw? That was a monster TX.

I could fit a modern 500kW rig in my basement. I could fit a 100kW rig in my living room. It's unfortunate timing that the state of the art has produced some very compact and efficient transmitter designs which could make superpower operation economical and actually benefit some stations. The current politics prevents this. I do, however, recall seeing some coverage maps indicating not a whole lot of difference in groundwave coverage above and beyond that offered at 50kW. Building penetration seemed to be improved though. The related issue of increasing man-made noise affecting HF, MW, and LF has not, and likely never will be addressed.

There actually was another push for superpower operation which began in 1962 when a small group of clear channel AM stations, including WLW, petitioned the FCC for 750 kW operating authority. Soon thereafter, another half dozen or more Class-1A stations joined asking for power levels of 500 kW up to 750 kW. After dragging through the legal process for a few years, the petitions were all denied. 

Superpower proponents did not give up, and the issue resurfaced again in 1975. Unfortunately the lengthly proceedings evolved in a direction that removed nighttime skywave protection and effectively abolished the clear channels. It also increased the power of Class IV local stations, saw the FCC flirt with a reduction to 9khz spacing, added or expanded pre-sunrise and post-sunset authority for many stations, and even considered the possibility of moving some clears to Longwave for expanded groundwave coverage. In the end, superpower was taken off the table, and the AM/MW band inherited the mess it has now. Maximum AM power can still inch up a bit. The 1982 "Rio" Treaty capped AM power at 100kW, but the FCC has refused to address lifting the 50kW maximum power level on AM/MW.


73,
Jim
WA2AJM/3

Bob,

Thanks for posting that incredible interesting video on WLW.  The shear size of generating 500 KW back in those days is awesome!  It was also interesting to learn that the average age of the developers were quite young.  The development effort was apparently shared between some of the great companies of the day and all accomplished in a pretty short amount of time. 

I hope what remains of the transmitter is preserved due to its historical significants.       

Joe - W3GMS   

I grew up in Cincy.  The 500 KW days were before my time but the stories abounded when I was a kid in 60's.  My dad was a teen in 1939 when FCC decided to make Powell Crosley go back to 50KW (understand they did continue high power ops briefly at night during early war years).   He used to tell me about it.   

Apparently folks up in the Mason area--near the transmitter site could hear music in their fillings due to rectification.  And there were stories of light bulbs lighting-up without need for 60 hz power. 

The interference reports did come in--as I understand was mostly from Canadian stations getting drowned out by the 700 kc flamethrower.  And remember hearing stories about getting song requests from the UK and diplomatic protests being lodged with US from Third Reich--being bombarded after dark with all that decadent mid-western American culture<hihi>.  Don't know how much of it is true. 

Cincinnati was a hub for a lot network talent in late 30's and a number of network shows originated there.  Red Skelton got his start there on a show called Avalon Time--later they moved it to Chicago.  Have heard a few of their old recordings--Peter Grant was the WLW announcer for Red.  When I was a kid in 60's, a much older Peter did evening news on WLW-T (Channel 5).  Understand that Doris Day got her start singing there--as Doris Kappelhoff.  And there were others.  My grandmother once told me that one of my dad's childhood friends had a mother that starred on a daytime network soap opera--she went to work everyday downtown where it was all done live in the WLW/Crosley studios. 

There were lots of advertisers who got plenty of coverage--especially at night--and the country/western shows were popular. 

All way before my time.  Powell Crosley (original WLW owner/Crosley electronics pioneer) sold out to Avco after the war (my T-368C was made by Avco-Crosley under a 55 Army Contract).