DX OPPORTUNITY on 670, 720 and 780 in Chicago

[davideduardo]

One also has to wonder if there was (or is) some consideration to co-location of 670 and 780 facilities. Both those large tracts of land they occupy are prime locations. Someone at CBS might be seeing those $$$$..... 780 sits at the intersection of two major freeways.

It's been done, but as the Hawaiian operations have proved, a diplex just 110 kHz apart ends up producing rather narrow bandwidths for each station, and the resultant sucky sound. Trying to pump HD Radio through such a close diplex would be even more dreadful than regular AM HD.

 

[audioguy]

One also has to wonder if there was (or is) some consideration to co-location of 670 and 780 facilities. Both those large tracts of land they occupy are prime locations. Someone at CBS might be seeing those $$$$..... 780 sits at the intersection of two major freeways.

It's been done, but as the Hawaiian operations have proved, a diplex just 110 kHz apart ends up producing rather narrow bandwidths for each station, and the resultant sucky sound. Trying to pump HD Radio through such a close diplex would be even more dreadful than regular AM HD.

Maybe in view of the $$ they would finally concede that HD AM isn't going anywhere, for just about every reason you can think of, and do it!

 

[davideduardo]

Maybe in view of the $$ they would finally concede that HD AM isn't going anywhere, for just about every reason you can think of, and do it!

When they look at the cost of combining the stations, including transmitter housing, generator capacity, the combiner and new ATUs, electrical systems, lost airtime, manpower, FCC filings, legal fees, consulting engineering costs and insurance... and when they add in the possible more narrow bandwidth... the savings probably just are not there.

As to the land... is there much demand for property at either of the sites to the extent that someone would buy the land for enough to pay the hundreds of thousands in direct costs?

 

[richllewis]

Down here in Mississippi we got the Cuban on 670, but this is most nights down here. 720 was KSAH, and in 780 we got a faint signal that sounded like someone giving a monologue or a lecture. It was so faint that I could not get an ID on the station. By the way WBBM went off the air at 2:06 CT and went back on the Air at about 3:45 CT.

 

[CADXER]

Here are my reception notes from the WSCR/WGN/WBBM silent period:

670 WSCR off the air promptly at 2:00 CST. Back on at 4:02 CST
720 WGN off the air at 2:07 CST. Back on at 3:54 CST.
780 WBBM off the air at 2:06 CST. Back on at 3:44 CST

670

Radio Rebelde from Cuba and another station noted with Spanish vocals early on (2:00 - 2:04), but as time went on only Cuba remained on the frequency. Internet reports suggest that the unidentified station was WWFE, Miami, Florida.
No luck hearing the KBOI test. Will review the tape later in case I missed the code, but I am not holding my breath.

720

Strong Mexican dominated the frequency, which was the Mexican XEDE.

780

Station with techno music noted from 0218 CST until 3:06 CST. Other DXers ided this as XEWGR from Mexico. Also heard in the mix was another Mewxican station, XEMTS with Radio Formula slogan. Strong Latin America station heard at 0221 looping SE/NW, which I presume was Radio Coro from Venezuela, which was heard by me in the past when WBBM wa soff the air.

Fairly dissapointing results. I expected to at least hear the KBOI test. However the auroral conditions really messed this otherwise great event.

The last few day the strong solar activity made for some unexpected reception on the AM band. At some points the band would go dead and the stations normally heard were completely absent. Sometime that makes it possible to hear other stations. That was the case last night on AM 1540, when the usual KXEL was nowehere to be heard. As a result I had Bahamas with fair signal and KEDE San Antonio, texas.

 

[schmave]

I haven't been to Chicago in about a year and haven't been close enough to log dependable AM reception of the big stations in a few months. Are 670 and 780 still running HD? 780 might be at night, but lately I haven't been able to tell with all the auroral activity going on. I can dream. Just love the full sound when it's without HD, not to mention the loud sidebands only a radio geek can appreciate.

 

[audioguy]

670 and 720 currently have it off; 780 persists. We are hoping they will turn it off too.

 

[[email protected]]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

The word on the street is that AM-670 is sitting on some valuable land so the CBS guys are looking into co-locating AM-670 on the WBBM AM-780 tower. With that done CBS can sell off the 670 site and bring in some sweet money.

The question is will the co-location expenses eclipse the land value ?

Co-locating two 50 Kilowatt stations, tuning them up, installing new transmitters and trying to keep each stations signal out of the other stations is an expensive endeavor.

 

[Tom Wells]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

The word on the street is that AM-670 is sitting on some valuable land so the CBS guys are looking into co-locating AM-670 on the WBBM AM-780 tower. With that done CBS can sell off the 670 site and bring in some sweet money.

The question is will the co-location expenses eclipse the land value ?

Co-locating two 50 Kilowatt stations, tuning them up, installing new transmitters and trying to keep each stations signal out of the other stations is an expensive endeavor.

Wow. At 50 kw, and WGN just slingshot's distance away that's gonna be one helluva honkin big tuning/trapping 3 way setup!

And it will probably throw some ugly intermods for an additional proportion of the audiences of all 3.

The iboc won't behave on the tiny plot surrounded by commecial zoning WSCR is at now.
I suspect is is reradiation/phasing from extensive/nearby also-grounded wiring/structures.

So it's a partial toss-up on thiinking they can get iboc back on 670 in a theoretically "clean" place wher where it's alredy woking,
vs, the costs of co-locating 2 50 kws only 100 khz apart.

Such required traps and narrowing of bandwidth would surely result in lopsided analog resonse,
not that anyone cares that the upper and lower sidebancds SHOULD sound the same if your sytem has proper linerity and bandwidth.
Co-locating must be a very conscious decision to throw away some the beauty of a widebanded single signal.

It's CBS, so it'll be interesting whatever happens. For now I can listen to WSM .

 

[w9wi]

I wonder if the specific (WBBM) site -- directly adjacent to a VERY busy freeway serving demographically-desirable commuters -- will be a factor in the decision?

 

[K4WRF]

Where it is a technical challenge, it’s not impossible or impractical to combine at a 110khz spacing. Kintronics has designed and constructed traps for as little as 50khz (not in this country). Either of the transmitter buildings more than likely have ample room and probably sufficient power company service entrance left over from the old power hog transmitter days to accommodate the additional load. You might spend a million dollars on a project like that. All-in-all not really any big deal or cost prohibitive considering the capital gain as-well-as reduced operating and maintenance cost over time. The 670 theoretical field operating on the WBBM tower is just sufficient to maintain Class A status of 364 mv/m, 362 mv/m is minimum, but it might be more favorable if they operated them from the 670 site. Down at WLS, there is a ~20x30 pole building at the bottom of the tower that still contains traps and networks that were used to combine the 890khz with 1000khz (120kc) while the WMVP towers were being replaced.
Best regards,
w/

 

[radioman148]

Where it is a technical challenge, it’s not impossible or impractical to combine at a 110khz spacing. Kintronics has designed and constructed traps for as little as 50khz (not in this country). Either of the transmitter buildings more than likely have ample room and probably sufficient power company service entrance left over from the old power hog transmitter days to accommodate the additional load. You might spend a million dollars on a project like that. All-in-all not really any big deal or cost prohibitive considering the capital gain as-well-as reduced operating and maintenance cost over time. The 670 theoretical field operating on the WBBM tower is just sufficient to maintain Class A status of 364 mv/m, 362 mv/m is minimum, but it might be more favorable if they operated them from the 670 site. Down at WLS, there is a ~20x30 pole building at the bottom of the tower that still contains traps and networks that were used to combine the 890khz with 1000khz (120kc) while the WMVP towers were being replaced.
Best regards,
w/

Anyone have any info on how difficult it was to move WNBC to the WCBS tower in the 60s? I realize this was 50 years ago, but I imagine a lot of thought had to go into that project.

 

[K4WRF]

Anyone have any info on how difficult it was to move WNBC to the WCBS tower in the 60s? I realize this was 50 years ago, but I imagine a lot of thought had to go into that project.
[/quote]

Kintronic labs rebuilt that one about five or six years ago. The WFAN/WCBS tower was once sectionalized but was altered some years ago. It employs quite a bit of top loading to make the minimum class A field for 660 obviously. 220kHz spacing diplex is relatively a piece of cake! I was told NBC left its long island location because of the land values and it was a two-tower directional there as well. Its not really clear to me why CBS opted to leave Columbia Island. Perhaps Scott Fybush knows more about that and can comment on it. At that time, it was quite an innovation...

Best regards
wh

 

[w9wi]

I have somewhere a paper on the original 660/880 diplex project. Will have to see if I can find a way to get it online.

 

[radioman148]

Anyone have any info on how difficult it was to move WNBC to the WCBS tower in the 60s? I realize this was 50 years ago, but I imagine a lot of thought had to go into that project.

Kintronic labs rebuilt that one about five or six years ago. The WFAN/WCBS tower was once sectionalized but was altered some years ago. It employs quite a bit of top loading to make the minimum class A field for 660 obviously. 220kHz spacing diplex is relatively a piece of cake! I was told NBC left its long island location because of the land values and it was a two-tower directional there as well. Its not really clear to me why CBS opted to leave Columbia Island. Perhaps Scott Fybush knows more about that and can comment on it. At that time, it was quite an innovation...

Best regards
wh
[/quote]

The reason I had heard that NBC left the Long Island transmitter site was because of the population growth further east on Long Island.
The thinking was that they needed an "ND" to better serve that area where the population was expanding. Can anyone confirm this?
w9wi, if you do find that paper I'd love to see it--thanks!

 

[Tom Wells]

i've heard complaints that L.I. ground conductivity is quite poor.

That's why the marshes of NJ are such a great deal for the city, but no so great for LI listeners.

 

[[email protected]]

i've heard complaints that L.I. ground conductivity is quite poor.

That's why the marshes of NJ are such a great deal for the city, but no so great for LI listeners.

I know first hand that the Long Island ground conductivity is real lousy (0.5 typ). Lot's of sand under the inch or so of real soil...

 

[audioguy]

Wow, that is even worse than SW Michigan, which also has sandy soil.

 

[davideduardo]

I know first hand that the Long Island ground conductivity is real lousy (0.5 typ). Lot's of sand under the inch or so of real soil...

The only place worse I have witnessed is the Coachella Valley in CA... the Palm Springs market. No signal covers the entire market, even daytime, and even with 10 kw.

Long Island is a sandbar. The Coachella Valley is a basin filled with sand.

 

[KR4BD]

Concerning Long Island AM Radio reception....It is truly HORRIBLE. In the mid-1980's I lived in Setauket, L.I. which is on the North Shore about 40 miles east of NYC "as the crow flies". NONE of the NYC blowtorches had a strong signal there. The ONLY LOCAL strength AMer day/night was WICC-600 from Bridgeport, CT located directly across the Long Island Sound from my location.