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WLW 500 kW Directional vs. 50 kW Nondirectional 5 mV/m and 1 mV/m 50% Skywave Map

I looked up Blaw Knox Towers on Wikipedia. It has a History of all of them, including one not usually remembered, for WKQI 95.5 in Oak Park, MI. It is just a top section design, but built at ground level.

It mentions that the WLW tower was reduced in height from 831 feet to 747 feet. I would suspect that the top sections were removed. I would assume it was done to reduce skywave to groundwave fading.

en.wikipedia.org

Blaw-Knox tower - Wikipedia

en.wikipedia.org en.wikipedia.org
 
It's discussions like this that make me keep coming back here, by the way. This is great stuff.

Getting back to the 500 kW issue - if WLW had remained the only station on 700, superpower would have made more sense. If you're not creating interference (or having co-channel interference created to you), then why not supply the most robust signal you can to as many people as possible?

This is what the small-c clear channel stations of the 30s wanted, and what they didn't get - but when the FCC declined to give them 500 kW (or more!), it essentially set things on the path that led to the breakdown of the clears in the 1960s.
 
Schroedingers Cat said:
I looked up Blaw Knox Towers on Wikipedia. It has a History of all of them, including one not usually remembered, for WKQI 95.5 in Oak Park, MI. It is just a top section design, but built at ground level.

It mentions that the WLW tower was reduced in height from 831 feet to 747 feet. I would suspect that the top sections were removed. I would assume it was done to reduce skywave to groundwave fading.

en.wikipedia.org

Blaw-Knox tower - Wikipedia

en.wikipedia.org en.wikipedia.org
Click to expand...
That's correct - both WLW and WSM were reduced in height after they learned more about groundwave-skywave cancellation.

WLW's original design put a cancellation ring over Indianapolis, Columbus and Louisville, while WSM's cancellation ring landed on Knoxville and Birmingham, or so the story goes.
 
fybush said:
The OWI took over all of the shortwave stations being operated by commercial broadcasters at the start of the war - Crosley's in Ohio, CBS in New Jersey and California, NBC in New Jersey and California, WRUL in Massachusetts, Westinghouse in Massachusetts and Pennsylvania, and GE in New York and California.

Some of the sites ended up as VOA sites after the war - the Crosley site, of course, as well as the CBS and RCA sites in California (Delano and Dixon). Others were operated under contract to VOA (Westinghouse's WBOS, for instance), and I think some of the equipment was moved to the Greenville NC sites after WBOS closed.

And of course a couple of the stations were returned to their owners after the war - KGEI in California and WRUL in Massachusetts.
Click to expand...

The old WRUL site in Scituate, Massachusetts was used for a while for WNYW, Radio New York Worldwide. I remember listening to a pre AT40 countdown show, it seems like it was on Saturdays, on 15440 kHz in the 19 meter band. I listened on my 1938 Vintage Westinghouse Table Radio, complete with a 6U5 Tuning Eye, and five individual presets with individual oscillator and received frequency LC adjustments for AM BCB.
 
Schroedingers Cat said:
The old WRUL site in Scituate, Massachusetts was used for a while for WNYW, Radio New York Worldwide. I remember listening to a pre AT40 countdown show, it seems like on Saturday, on 15440 kHz in the 19 meter band. I listened on my 1938 Vintage Westinghouse Table Radio, complete with a 6U5 Tuning Eye, and five individual presets with individual oscillator and received frequency LC adjustments for AM BCB.
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I vaguely remember WNYW, I believe with English and Spanish programming and CBS News,
 
Schroedingers Cat said:
The old WRUL site in Scituate, Massachusetts was used for a while for WNYW, Radio New York Worldwide. I remember listening to a pre AT40 countdown show, it seems like it was on Saturdays, on 15440 kHz in the 19 meter band. I listened on my 1938 Vintage Westinghouse Table Radio, complete with a 6U5 Tuning Eye, and five individual presets with individual oscillator and received frequency LC adjustments for AM BCB.
Click to expand...
Yup. WRUL became WNYW under Bonneville, and then WYFR under Family Radio. They moved it to Florida in the mid-70s, and it was sold a while back and is now WRMI from the Okeechobee, Florida site.
 
Schroedingers Cat said:
I looked up Blaw Knox Towers on Wikipedia. It has a History of all of them, including one not usually remembered, for WKQI 95.5 in Oak Park, MI. It is just a top section design, but built at ground level.

It mentions that the WLW tower was reduced in height from 831 feet to 747 feet. I would suspect that the top sections were removed. I would assume it was done to reduce skywave to groundwave fading.

en.wikipedia.org

Blaw-Knox tower - Wikipedia

en.wikipedia.org en.wikipedia.org
Click to expand...
The Wikipedia page does not include WSUN, St. Petersburg, FL. (now WDAE). They had two Blaw-Knox towers.
 
I have read that the KDKA antenna had to be redesigned two or more times to deal with the skywave to groundwave issues. It is quite complicated, more than originally imagined. It also involves real life ground conductivity and its Winter Summer variations, and the differing Seasonal Critical Hours skywave, different hours being affected at different times of the year. And of course, the skywave fading and intensity itself. All of these determine approximately when and where total fadeouts occur where Skywave FI=Groudwave FI. Ideally, stations would have had to have different antennas at different times of Day and Night.
 
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Didn't WBZ once apply for a power increase to 400 kW along with a transmitter move to Provincetown?
 
Kemosabe said:
Didn't WBZ once apply for a power increase to 400 kW along with a transmitter move to Provincetown?
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It did. Many of the (small-c) clear channel stations filed similar applications in the late 1930s, to have them on file in case they succeeded in changing FCC policy.
 
fybush said:
It did. Many of the (small-c) clear channel stations filed similar applications in the late 1930s, to have them on file in case they succeeded in changing FCC policy.
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Seems to me the footings for that tower were still there for some time afterwards.
 
Well, even with seawater conductivity, you still have the Inverse Square Law/Inverse Field Law in place. So if you're way out at the end of Cape Cod, you're much farther than from Hull. I don't know what kind of antenna they planned, but there really isn't much advantage to being nondirectional and sending your signal into the Atlantic Ocean. WKBW has a "Coverage Map" from the 1960s where they show all the places they received reports from, in Western Europe and Northwest Africa as well as the Americas, but even then and of course now, what good was/is it to the "bottom line"?
 
fybush said:
That's correct - both WLW and WSM were reduced in height after they learned more about groundwave-skywave cancellation.

WLW's original design put a cancellation ring over Indianapolis, Columbus and Louisville, while WSM's cancellation ring landed on Knoxville and Birmingham, or so the story goes.
Click to expand...

I like this historical discussion. My dad and uncle used to listen to the Grand Ole Opry on WSM, using a five tube radio. WSM came in astoundingly well in southern Alabama at night. Where I lived WBT came in better at night than the local station on the graveyard channel. The local station had to make do with 250 watts at night , so they invested in audio processing and they had a great engineer. I was fortunate to learn from them.
 
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fybush said:
That's correct - both WLW and WSM were reduced in height after they learned more about groundwave-skywave cancellation.

WLW's original design put a cancellation ring over Indianapolis, Columbus and Louisville, while WSM's cancellation ring landed on Knoxville and Birmingham, or so the story goes.
Click to expand...
What was fascinating to observe was the changes in the KFI signal while they negotiated the rebuild of the tower that fell in an aviation accident. When they used one of the old KRKD towers, I can remember that the night signal became compromised going East on the 10 Freeway from around Redlands all the way to Banning. After Banning, the signal was clean again, but that zone was really a rugged reception area.

With the new tower, the cancellation occurs somewhere east of Desert Crossing and is gone by the time one reaches Blythe, also along the 10.
 
Schroedingers Cat said:
A Professional Survey of the proposed TL site, and a bunch of stakes and flags? That sounds plausible.
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I'd be surprised if it got that far - and if it did, those stakes and flags would have been gone within a year at most.

What did survive over the years (and what Big A might have been thinking of) were the wooden poles that held the WBOS shortwave antennas at the WBZ Hull transmitter site, and some footings from the previous WBZ site out in Millis, souhwest of Boston. I don't think anything remains today of either of those, though.
 
Great discussion, gentlemen.......
Greg Strickland said:
I like this historical discussion. My dad and uncle used to listen to the Grand Ole Opry on WSM, using a five tube radio. WSM came in astoundingly well in southern Alabama at night.
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I had an aunt who lived all her life in a small town in northern Ontario...about 250 miles north of Lake Superior. Her town didn't get TV or daytime radio service until the early 1960s when the CBC set up shop nearby. Her favorite radio program, which she listened to every Saturday night, was Grand Ole Opry on WSM. She only had one small radio (I presume 5 tubes), and told me she never had a problem with WSM reception. Or for that matter, her other favorite station, which was WGN.
 
WGY tested at 200 kW as W2XAG in 1930 and KDKA tested at 400 kW as W2XAR in 1931.

The first night WLW powered up the superpower transmitter at W8XO in 1934, the engineers pushed it to see what it would do. Apparently it got to 800 kW without trouble.

Meanwhile, at one time there were nine stations in Mexico with at least 100 kW.

Among the applications from the 1930s to the 1960s:
WBZ 400 kW
WSB 500 kW
WSM 500 kW (1930s), 750 kW (1962)
WHO 500 kW (1930s), 750 kW (1962)
WHAS 500 kW
KSL 500 kW (1930s, 1963)
WLW 650 kW (1930s), 750 kw (1962)
WOAI 750 kW
WJR 750 kW (1962)
WGN 750 kW (1962)
WCCO 750 kW (1963)
 
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