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WBBM AM to diplex with WSCR

KeithE4 said:
The land that the WBBM tower sits on has to be worth close to $100M. Cutting power a few kilowatts won't hurt coverage much.
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It won't hurt coverage at all. Using the taller 670 tower increases efficiency, so they get the same field strength as they did with the old tower but with lower transmitter power.
 
DavidEduardo said:


It won't hurt coverage at all. Using the taller 670 tower increases efficiency, so they get the same field strength as they did with the old tower but with lower transmitter power.
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It's a smart move. Much reduced transmitter operating costs. The taller tower may produce slightly less nighttime skywave but AM stations typically don't have many skywave advertisers.
 
DavidEduardo said:


It won't hurt coverage at all. Using the taller 670 tower increases efficiency, so they get the same field strength as they did with the old tower but with lower transmitter power.
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I did not look at the electrical height of the 670 tower at 780, but another advantage might be a moving of the cancellation zone out a greater distance.
 
I'm roughly 25 miles from these two sticks, and shouldn't notice the slightest difference from the change. I'm a little unclear, however, what the point is of running the additional 7kw at night.
 
cyberdad said:
I'm roughly 25 miles from these two sticks, and shouldn't notice the slightest difference from the change. I'm a little unclear, however, what the point is of running the additional 7kw at night.
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The lower day power is probably due to the otherwise increased coverage that 50 kw would give; that increase might cause interference with some co-channel or adjacent channel stations. Nights would have different protection issues as some of the stations protected daytime may be daytimers.
 
frankberry said:


It's a smart move. Much reduced transmitter operating costs. The taller tower may produce slightly less nighttime skywave but AM stations typically don't have many skywave advertisers.
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I don't advertise but I do listen to it ever once in a while in NE Ohio at night. Hope I'll still be able to pick it up.
 
radioman148 said:
According to the FCC filing WBBM-AM will share WSCR tower and run less power.
‘
https://licensing.fcc.gov/cdbs/CDBS....jsp?appn=101768529&qnum=5120©num=1&exhcnum=1
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staggmovie said:
Not that I am saying i don't believe you, but which page is this on that states what you are reporting?
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Slightly different URL from the original one posted above - the one below should work - opens a PDF file:

https://licensing.fcc.gov/cdbs/CDBS...?appn=101768529&qnum=5120&copynum=1&exhcnum=1

A historical look at the WBBM tower site from Scott Fybush's website:

https://www.fybush.com/site-20171012/
 
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On the eastern fringes of both stations' coverage areas, the field strength of WSCR and WBBM during the day is almost identical from their existing TX sites. WBBM's audio processing has better "punch" than that of WSCR, so WBBM's signal seems able to overcome undesired noise a bit more easily.

I have a hard time believing there won't be at least some noticeable loss of signal strength in distant areas served by the groundwave signal, especially in areas to the north and east of Chicagoland. (I realize these considerations aren't terribly important from a business standpoint.) 50 kW > 35 kW.

There could be some frustrated Bears fans in SW Michigan and portions of northern Indiana if the TX move results in signal degradation there.

Finally, why do the engineering exhibits submitted by WBBM to the FCC make such a big point about protecting CKLW's signal on American soil? I thought Canadian stations were not required to be protected, so long as any interference caused by American stations didn't extend across the border? (By the way, the IBOC sidebands from 810 WGY interfere big time with CKLW in plenty of areas in the province of Ontario.)
 
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Does this change their class? Can AM Daytimer's on 780 get nighttime service? Back in the early 80's their was a push to get clear channel AM'S to reduce nighttime power so Daytimer's could get night service. The Clear' s fought to stop that. Now Clear Channels just drop power i.e. WOWO, (WDCD Wants to. ) WMEX and WDCD stating Costs both have remain Slient STA's. THAT is Defeating the Purpose of the Clears. NOW WITH THE Hurricanes ,Flooding and threat of War these stations need to be on the air at full power keeping America informed.
 
PHIL Z said:
WMEX and WDCD stating Costs both have remain Slient STA's. THAT is Defeating the Purpose of the Clears. NOW WITH THE Hurricanes ,Flooding and threat of War these stations need to be on the air at full power keeping America informed.
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Both stations have challenging patterns and are at the wrong end of the dial. In the case of WDCD, Kid Crawford wanted to try running at reduced power, and then he'd let the commission know if it worked. FCC policy doesn't work that way - you either request a minor modification, or an STA based on damage to your xmttr/tower, or a financial hardship. After being turned down, Crawford turned it off for the umpteenth time citing costs and no listeners. Not sure Albany misses 15~Forty at all.
 
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PHIL Z said:
Does this change their class? Can AM Daytimer's on 780 get nighttime service? Back in the early 80's their was a push to get clear channel AM'S to reduce nighttime power so Daytimer's could get night service. The Clear' s fought to stop that. Now Clear Channels just drop power i.e. WOWO, (WDCD Wants to. ) WMEX and WDCD stating Costs both have remain Slient STA's. THAT is Defeating the Purpose of the Clears. NOW WITH THE Hurricanes ,Flooding and threat of War these stations need to be on the air at full power keeping America informed.
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This does not change the class, as the field strength in any direction is essentially unchanged. The power reduction appears to be entirely based on the need to protect newer stations on the channel and on adjacents from increased interference, which would be the case if the same power using a more efficient antenna were used.

The only change in groundwave coverage is the product of moving to a site that is a number of miles from the old one. A bit more to the south, a bit less to the north, but in terms of square miles, about identical.

It is not necessary to have 50 kw day and night to be a clear channel station, as KPMC in Bakersfield showed for many decades.

And neither 1540 in Albany nor 1510 in Boston were serving any useful news dissemination purpose. Albany was paid religion and Boston was a lame talker with no news department. At the high end of the dial and very directional, neither is really a significant facility.
 
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PHIL Z said:
Now Clear Channels just drop power i.e. WOWO, (WDCD Wants to. )
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WOWO didn't "just drop power." Percy Sutton purchased the Fort Wayne station for the sole purpose of lowering its nocturnal power to permit WLIB, Inner City Broadcasting's co-channel in New York, to broadcast after sunset. After the FCC change, Sutton sold WOWO.
 
KFMB San Diego is 5k Day and 50k night at 7~Sixty. They must have a lot of fish listening at night as much of their RF goes out into El Pacifico. Recently the station requested a modification to reduce their night power to 10k, but shortly after the filing, KFMB requested the application be dismissed. Maybe they were trying to save electricity...or maybe someone upstairs thinks owning a 50kw station is a big thing. In reality, a lot of the 50kw stations don't need that kind of power to serve a metropolitan area at night. Listeners out in the hinterlands (and ships at sea) have plenty of sources for news and information.
 
With all the noise in today's world, 50 kw is not always sufficient to cover a metro area.
 
mimo said:
With all the noise in today's world, 50 kw is not always sufficient to cover a metro area.
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Definitely true. I recently worked with an AM news and talk station in Buenos Aires, a market of about 17 million. We were on 710 AM with 100 kw, but still not happy with the noise in the center city areas so we directionalized moderately to send the equivalent of 125 kw towards downtown. That did the trick. The low frequency new Nautel transmitters and a nice marshy transmitter site gave the needed signal in the market.
 
DrAkbar said:
KFMB San Diego is 5k Day and 50k night at 7~Sixty. They must have a lot of fish listening at night as much of their RF goes out into El Pacifico. Recently the station requested a modification to reduce their night power to 10k, but shortly after the filing, KFMB requested the application be dismissed. Maybe they were trying to save electricity...or maybe someone upstairs thinks owning a 50kw station is a big thing. In reality, a lot of the 50kw stations don't need that kind of power to serve a metropolitan area at night. Listeners out in the hinterlands (and ships at sea) have plenty of sources for news and information.
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Well, someone must be going out to interview the fish because if you Google Map the transmitter site and drag the little guy to the roadway closest to the tower, there's a fairly nice boat sitting between the two towers.
 
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