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WCPT

O

OldChicago

Recently, AM 820 WCPT added a second xmtr site in order to provide 24
hour service using a directional antenna system. About the same time, the station changed its legal COL from Chicago to Western Springs, the location of its nighttime xmtr. What was the reason for this. Some stations change their COL, but not anything else. It can even be a small to another small town. Why do stations do that?


Old Chicago
 
OldChicago said:
Recently, AM 820 WCPT added a second xmtr site in order to provide 24
hour service using a directional antenna system. About the same time, the station changed its legal COL from Chicago to Western Springs, the location of its nighttime xmtr. What was the reason for this. Some stations change their COL, but not anything else. It can even be a small to another small town. Why do stations do that?


Old Chicago
Click to expand...

I'm guessing that in this case it has to do with the quality of their signal in the COL. In other words from Western Springs that night WCPT wouldn't put a strong enough signal into Chicago which was their COL. Just my guess, feel free to correct me if I'm wrong.
 
It's a combination of two quirks in the FCC rules.

Section 307(b) of the Communications Act of 1934 gives the FCC a mandate to make a “fair, efficient and equitable” distribution of broadcast services, and for many years now the Commission has interpreted that as favoring "first local service" in as many different communities of license as possible. So a "first local service" to Willow Springs (not Western Springs) has a higher priority to the FCC under 307(b) than the ninth AM signal in Chicago...even if the station's daytime transmitter remains on 16th Street in the city of Chicago.

And the FCC's own AM rules (section 47 CFR 73.24 (i), if you're scoring at home) requires that an AM station cover at least 80% of its community of license at night. The new 820 night signal can't cover the sprawling mass of Chicago itself after dark, but it can cover Willow Springs just fine. If WCPT could have covered 80% of the city of Chicago with a night signal, it could have added the second site without changing city of license.
 
At the old Elmhurst site, four towers had been built which were probably in excess of 1/2 wavelength to go fulltime the first time around. The City of License was still Chicago. They lost the site and became a daytime only station again from the WSBC/old WXRT site. I was curious at the time about how they were able to keep the Chicago COL. Does anyone know? Perhaps someone has access to the application. Maybe there was a waiver granted. I thought that as much interference as there was from WBAP, they would have to have changed to a small nearby community.
 
Different era, different rules. When then-WAIT added night power, I'm pretty sure it was under the old set of rules that said you had to deliver 25 mV/m of signal over the main post office of your COL. Stations licensed under those old rules were grandfathered in.
 
I remember quite a few stations changing City of License back at that time (1980s) that changed, but I think it was the NIF contour not covering the old City. By that time, arrays had to be further out to cover new development and meet the 1% rule. With NIFs often exceeding 25 mV/m and Class IIIs limited to 5000 watts day and night, the NIF often only got out a few miles. Once again, does anyone have a really old AMDATA.DAT database from that era? There's still quite a few old Class III-Ss that find it difficult to go from Class D to Class B for this reason. Sometimes, there's no suitable COL that works.
 
I think both WAIT 820 and WJJD 1160 both applied for night facilities before stations on I-A Clear Channels were permitted to do so. As I recall, legal wrangling forced the FCC to accept the applications anticipating when night facilities would be permitted, without any further restrictions or regulations like protecting any new stations on the frequencies, and any further changes regarding City Of License night coverage. When they changed the rules, the applications were granted. However, WJJD was eventually forced to give up its 50 kW Limited Hours service between sunset in Chicago and sunset in Salt Lake City.

That may be why WAIT possibly kept the Chicago City Of License the first time they went fulltime. Again, I'd like to see what the old night pattern parameters were. I called once about the COL thing, wondering how they kept Chicago with just 1000 watts. The guy didn't know why, but said the towers were aligned along a 38 degree azimuth as I recall.

As I recall, WJJD had initially applied for 10 kW nighttime from Des Plaines. It eventually became 4.4 kW and 5 kW at different times.
 
I stand to be corrected, but I'm pretty sure WCPT's COL is Willow Springs....not Western Springs.
 
Schroedingers Cat said:
That may be why WAIT possibly kept the Chicago City Of License the first time they went full time. Again, I'd like to see what the old night pattern parameters were. I called once about the COL thing, wondering how they kept Chicago with just 1000 watts. The guy didn't know why, but said the towers were aligned along a 38 degree azimuth as I recall.
Click to expand...

38° azimuth does sound about right‡, as I remember those towers near I-290 in Elmhurst. Trouble is, the main lobe of that 1kW signal missed most of the city of Chicago except the NW, far North and NE sides of Chicago and did a better job of hitting the suburbs of Park Ridge, Niles, Morton Grove, and Skokie than the city of Chicago itself! The databases say the COL is Willow Springs, but the night transmitter and 6 towers are actually less than 2 miles fromthe eastern city limits of Joliet*, so the signal has to travel at least 20 miles before it even reaches the SW side of Chicago! *http://maps.google.com/maps?f=q&hl=en&q=41.54167,+-88.03417+(WCPT-AM)&om=1 ‡Current azimuth is about 18° http://transition.fcc.gov/ftp/Bureaus/MB/Databases/AM_DA_patterns/1365197-111122.pdf
 
stormy01 said:
Schroedingers Cat said:
That may be why WAIT possibly kept the Chicago City Of License the first time they went full time. Again, I'd like to see what the old night pattern parameters were. I called once about the COL thing, wondering how they kept Chicago with just 1000 watts. The guy didn't know why, but said the towers were aligned along a 38 degree azimuth as I recall.
Click to expand...

38° azimuth does sound about right‡, as I remember those towers near I-290 in Elmhurst. Trouble is, the main lobe of that 1kW signal missed most of the city of Chicago except the NW, far North and NE sides of Chicago and did a better job of hitting the suburbs of Park Ridge, Niles, Morton Grove, and Skokie than the city of Chicago itself! The databases say the COL is Willow Springs, but the night transmitter and 6 towers are actually less than 2 miles fromthe eastern city limits of Joliet*, so the signal has to travel at least 20 miles before it even reaches the SW side of Chicago! *http://maps.google.com/maps?f=q&hl=en&q=41.54167,+-88.03417+(WCPT-AM)&om=1 ‡Current azimuth is about 18° http://transition.fcc.gov/ftp/Bureaus/MB/Databases/AM_DA_patterns/1365197-111122.pdf
Click to expand...

Where I live in the near north suburbs WCPT's night signal is practically useless. WBAP usually dominates them.
 
I remember that in November of 1969, I was in the basement of my Uncle's house in NW Suburban Chicago, tuning an old tube table radio he had, and hearing WFAA or WBAP blaring in on 820 after WAIT signed off at Grapevine sunset. I had already looked at the skywave graphs in the NAB Engineering Handbook, and it seems that the 10% skywave for WFAA/WBAP was about 1 mV/m for that distance. Then, tuning up the dial to WLS on 890, I was amazed hearing that Bob Seger actually had a national breakout hit record with "Ramblin' Gamblin' Man", the first time he had a hit that was big outside Michigan and a few small markets in neighboring states.

I don't know how far apart the Elmhurst towers were. If they were spaced at 120-135 degrees with a -60 to -45 degree phase difference between successive towers along the 38 degree azimuth, it would have had a wide lobe that would have served more of Chicago than a strict 90 degree spacing with -90 phase classic cardioid arrangement.
 
cyberdad said:
I stand to be corrected, but I'm pretty sure WCPT's COL is Willow Springs....not Western Springs.
Click to expand...

I too stand corrected since I wrote the leading message on the subject.

Thank you to those who replied and and answered my question.

Old Chicago
 
OldChicago said:
cyberdad said:
I stand to be corrected, but I'm pretty sure WCPT's COL is Willow Springs....not Western Springs.
Click to expand...

I too stand corrected since I wrote the leading message on the subject.

Thank you to those who replied and and answered my question.

Old Chicago
Click to expand...

Hey...it's one of those springs that begins with "W"  ;D

As for Radioman's observation about the current nighttime signal... 

Up where I am in McHenry County, the signal IS listenable if you null WBAP.  But in most circumstances....particularly with a car radio....it would not be listenable.  Let alone competitive.  Daytime signal is fairly good around here, but definitely not as good as it was when it was coming from the old chicken farm site north of Elmhurst.
 
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