WCNN 680

[alok]

I has asked this once before but this time I got to see WCNN's transmitter site about a month ago ,so it got me wondering again about WCNN.

It seems that WPTF 680 puts a decent amount of skywave at Atlanta ,so how is it that WCNN got to operate nights ? I am sure WCNN is strong in Atlanta proper at night but when you get say 25-30 miles or so SW of Atlanta ( in WCNN's main lobe ) is there any interference from WPTF ?

I spent time in the Cumming area ( NE of Atlanta ) ,WCNN was strong during the day but gone at night due to nulls they have for protection to WPTF at night.

Also the minor lobes WCNN have that go NW ,what do these suppose to cover , the biggest one is at about 330 deg the other much smaller is at about 290 deg.

I noticed at WCNN's transmitter site high voltage tension lines close to site ,were these lines there before the site was built or did they come afterwards ?
It would seem these lines must effect the pattern and were most likely planned for one way or another in the design of WCNN's antenna system.


Al

 

[jabba17]

I know that if you drive under those high voltage lines along Pleasant Hill (also in Gwinnett), many times 680 will swamp the AM dial.

I'm guessing the NW nulls are to protect WMFS out of Memphis, which has the feet of a snow-angel night pattern in the northern half of Mississippi. https://radio-locator.com/info/WMFS-AM

In addition to WPTF, there's also WCTT in Corbin, KY, in the big NE null. It's a tiny class B, but they actually have more licensed power at night. https://radio-locator.com/info/WCTT-AM
Also in the NE null is another tiny class B, WHBE. https://radio-locator.com/info/WHBE-AM

 

[Gregg.]

When you look at a map on, say, Radio-Locator.com or some similar site, I don't think you can draw conclusions on little lobes here and there. That may just be due to local topography or nearby buildings. Even a non-directional station does not usually have a perfectly round pattern. It's the major pattern features that count.

In WCNN's nighttime signal, we can conclude that it must protect nearly all areas north of Atlanta, including Raleigh, Memphis and other regions. But to read more than that into it may not be accurate.

As for how WCNN got nighttime authorization, let's remember WPTF is only a Class B. So to have other stations on 680 at night in the South, in Atlanta and Memphis, is not unusual. If WPTF were a Class A, that would be a different story.

The only Class A on 680 is KNBR San Francisco. It has a 50,000 watt, non-directional signal around the clock. The other 50,000 watt directional Class Bs, WPTF Raleigh, WRKO Boston, CFTR Toronto, and the lesser-powered stations like WCNN, all must co-exist on 680, a very crowded frequency east of the Rockies.

 

[ThePowerCow]

Now to find out where North Atlanta is

 

[secondchoice]

When you look at a map on, say, Radio-Locator.com or some similar site, I don't think you can draw conclusions on little lobes here and there. That may just be due to local topography or nearby buildings. Even a non-directional station does not usually have a perfectly round pattern. It's the major pattern features that count.

In WCNN's nighttime signal, we can conclude that it must protect nearly all areas north of Atlanta, including Raleigh, Memphis and other regions. But to read more than that into it may not be accurate.

As for how WCNN got nighttime authorization, let's remember WPTF is only a Class B. So to have other stations on 680 at night in the South, in Atlanta and Memphis, is not unusual. If WPTF were a Class A, that would be a different story.

The only Class A on 680 is KNBR San Francisco. It has a 50,000 watt, non-directional signal around the clock. The other 50,000 watt directional Class Bs, WPTF Raleigh, WRKO Boston, CFTR Toronto, and the lesser-powered stations like WCNN, all must co-exist on 680, a very crowded frequency east of the Rockies.

Another station 680 had to deal with was WRGC Silvia NC 114 miles away. They were granted a construction permit to move from 1480 daytime to 680 in 1970. IIRC it was a class B with 2 transmitter sites on 680. They got a FM translator and shoehorned in 5KW none directional on 540 class D. The circles on the FCC filings and radio-locator are very optimistic and the overlapping WGTH is on paper only. The mountains and super poor soil conductivity make AM coverage dismal in this area. There is a lot more to WRGC’s story but that would be on the North Carolina boards.

 

[RoddyFreeman]

As I recall, the Atlanta stations at 680 and 640 were built at just about the same time in the late 80's. Was there a relaxation in FCC rules that allowed this to happen?

 

[jabba17]

As I recall, the Atlanta stations at 680 and 640 were built at just about the same time in the late 80's. Was there a relaxation in FCC rules that allowed this to happen?

640, as you said, came around in the late 80s when WGST moved from 920 to 640.

680 came on the air in the late 60s, daytime only (IIRC 25kW in 1968 from a single tower in Brookhaven, I mean North Atlanta*) until they moved out to the 8-tower array in Peachtree Corners in the late 1970s/early 1980s, which enabled them to go 50kW-DA daytime and shortly thereafter add a night signal. I have an aircheck of Neal Boortz signing off WRNG from 1979 (it used to be on the GRHOF site), so they must have added their night signal shortly after that.

680 picked up Georgia Tech sports from WGST 920 (who had had Tech sports from the beginning, "GST" meaning "Georgia School of Technology") sometime 1983-1984-ish, which wouldn't have worked without a night signal for hoops.

David Eduardo's Broadcast Journal collection has the exact years.

*the city of North Atlanta was dissolved in 1965 and was re-incorporated as Brookhaven recently.

 

[RoddyFreeman]

640, as you said, came around in the late 80s when WGST moved from 920 to 640.

680 came on the air in the late 60s, daytime only (IIRC 25kW in 1968 from a single tower in Brookhaven, I mean North Atlanta*) until they moved out to the 8-tower array in Peachtree Corners in the late 1970s/early 1980s, which enabled them to go 50kW-DA daytime and shortly thereafter add a night signal. I have an aircheck of Neal Boortz signing off WRNG from 1979 (it used to be on the GRHOF site), so they must have added their night signal shortly after that.

680 picked up Georgia Tech sports from WGST 920 (who had had Tech sports from the beginning, "GST" meaning "Georgia School of Technology") sometime 1983-1984-ish, which wouldn't have worked without a night signal for hoops.

David Eduardo's Broadcast Journal collection has the exact years.

*the city of North Atlanta was dissolved in 1965 and was re-incorporated as Brookhaven recently.

I believe 640 was originally built by a minority operator who got into financial trouble in short order. After that, 640 became WGST.

 

[jabba17]

I believe 640 was originally built by a minority operator who got into financial trouble in short order. After that, 640 became WGST.

I think you are correct; IIRC the 640 allocation was part of a minority set-aside, and was subsequently picked up by Jacor.

Question for the technical folks: Did the availability of 640 in the late 80s have anything to do with it being one of the old CONELRAD frequencies? Or was it due to the parting out of the clear-channel frequencies to allow distant operators to share the frequency (albeit with reduced or directional night power)?

640 has KFI in LA and CBN in Newfoundland, making it "available" for a southeastern US station under the relaxed clear-channel rules. Were the two Florida class B's on 640 (WVLG and WMEN) around before 640 in Atlanta? Otherwise WGST on 640 could have gone directional south at night with a well-placed array on the northside.

 

[secondchoice]

Question for the technical folks: Did the availability of 640 in the late 80s have anything to do with it being one of the old CONELRAD frequencies? Or was it due to the parting out of the clear-channel frequencies to allow distant operators to share the frequency (albeit with reduced or directional night power)?

I had an "old timer" engineer tell me that the old CONELRAD system was various stations transmitting on the two frequencies at different times. He said some stations were suppose "change frequencies" and transmit on 640 or 1240. This would have been a technical nightmare because most of the transmitters at that time had crystals that would have to be changed, and the antenna, modulation meter and transmitter would have to be re tuned. I don't know if this part of his story was true. When I worked at KIUL they still had the bomb shelter.

 

[RoddyFreeman]

I had an "old timer" engineer tell me that the old CONELRAD system was various stations transmitting on the two frequencies at different times. He said some stations were suppose "change frequencies" and transmit on 640 or 1240. This would have been a technical nightmare because most of the transmitters at that time had crystals that would have to be changed, and the antenna, modulation meter and transmitter would have to be re tuned. I don't know if this part of his story was true. When I worked at KIUL they still had the bomb shelter.

The WSB-AM site contains a fallout shelter.

 

[davideduardo]

I had an "old timer" engineer tell me that the old CONELRAD system was various stations transmitting on the two frequencies at different times. He said some stations were suppose "change frequencies" and transmit on 640 or 1240. This would have been a technical nightmare because most of the transmitters at that time had crystals that would have to be changed, and the antenna, modulation meter and transmitter would have to be re tuned. I don't know if this part of his story was true. When I worked at KIUL they still had the bomb shelter.

The way CONELRAD worked was by having, in each operational zone, a number of stations set to participate in the system. Upon activation, all stations would shut down. The ones that were CONELRAD participants would come back on at low power on either 640 or 1240, and then they would alternate among the other local stations so that none was on the air long enough for a missile to "lock onto it".

Stations had a CONELRAD tuning circuit in their transmitter for 640 or 1240. Because the operation was low power, the tuning of some components was not as big a problem as trying to put full power into a mismatch load.

The overlying principle of the system was that if there were hundreds and hundreds of stations, all on 640 or 1240, Russian homing devices would be confused and not know where to explode. This was a rather valid assumption in the pre-GPS era.

There were a number of full CONELRAD tests in the 50's and early 60's. I heard two of them, and they involved every station signing off and the initiation of CONELRAD programming on the two frequencies. The tests worked, and you could hear the transmitters going on and off.

 

[RoddyFreeman]

The WSB-AM site contains a fallout shelter.

The WSB site also has a brick wall around the transmitter building, I suppose to keep out illegal immigrants.

 

[jabba17]

The WSB site also has a brick wall around the transmitter building, I suppose to keep out illegal immigrants.

Probably to keep out rogue shoppers and FRNs (friendly radio nuts).

 

[MediaMan]

When you look at a map on, say, Radio-Locator.com or some similar site, I don't think you can draw conclusions on little lobes here and there. That may just be due to local topography or nearby buildings. Even a non-directional station does not usually have a perfectly round pattern. It's the major pattern features that count.

In WCNN's nighttime signal, we can conclude that it must protect nearly all areas north of Atlanta, including Raleigh, Memphis and other regions. But to read more than that into it may not be accurate.

As for how WCNN got nighttime authorization, let's remember WPTF is only a Class B. So to have other stations on 680 at night in the South, in Atlanta and Memphis, is not unusual. If WPTF were a Class A, that would be a different story.

The only Class A on 680 is KNBR San Francisco. It has a 50,000 watt, non-directional signal around the clock. The other 50,000 watt directional Class Bs, WPTF Raleigh, WRKO Boston, CFTR Toronto, and the lesser-powered stations like WCNN, all must co-exist on 680, a very crowded frequency east of the Rockies.

The effort to build another AM radio station in Atlanta which would become WRNG and is now WCNN, began with the FCC in 1959 when Charles Smithgall, Sr. of Gainesville, GA filed for 1150, 1 kw daytime only, but later that same year amended his application to 680 with 5 kW day and night using a five tower array proposed near Ashwood Dunwoody Road northeast of Buckhead. By the time the station was licensed in January 1968, the permit had been modified to a 5 kw daytimer with a single tower behind the WQXI and then WGST 920 site off Cheshire Bridge Road. The tower is now used by 970 and 1690. By 1970 the station had increased its daytime only signal to 25,000 watts non directional. In 1980 the present 10kw eight tower array for nighttime was licensed. The daytime site remained off Cheshire Bridge at 25 kW. Before the nighttime was granted by the FCC, WPTF in Raleigh filed against the proposed but Ring Radio, Inc. was successful in beating back WPTF's opposition which lasted four years before the FCC There was also extended battle of many years and lots of lawyer fees between WRNG and WRGC in Sylva, NC which had filed to move from 5kw daytime only on 1480 to 680 with 1 kW day and 250 watts (two towers) nighttime. In 1979, daytime power on WRNG was increased to 50,000 watts using two of the eight towers at the present site. With this pattern, WRNG basically maintained its 25 kW signal toward WRGC. The most severe protection WCNN nighttime has it toward WPTF in Raleigh. Less than 100 watts can be transmitted toward WPTF. There are also deep nulls to protect the 680 in Memphis, TN and less severe toward the Class A station on 680 in San Francisco. There is some limit to Corbin, KY just as there was toward WRGC in Sylva and a 680 in Charleston, WV but those three stations received so much interference from WPTF, they didn't have to be protected as much by WCNN. When WCNN was first licensed North Atlanta was a census designated place which qualifies under FCC rules as a licensed location.

 

[RoddyFreeman]

I believe the Cheshire Bridge Road tower is also used by 1190.

 

[Ccook55]

I currently live in Cumming. Last evening around 5 PM while out to get some gasoline, WPTF was coming in and the sun had not even set yet. WCNN hadn't powered down either. What was up with that?

 

[jabba17]

I currently live in Cumming. Last evening around 5 PM while out to get some gasoline, WPTF was coming in and the sun had not even set yet. WCNN hadn't powered down either. What was up with that?

FCC sunset for Atlanta in January is 5:45 PM. FCC sunset for Raleigh in January is 5:30 PM. So you had both stations running their day signals while skywave was starting to occur (which it will before sunset--that's why some stations have to observe reduced-power "critical hours" two hours after sunrise and two hours before sunset). Now, in December Atlanta FCC sunset is at 5:30 while it's 5:00 in Raleigh, which may be why this just "appeared".

FCC Monthly Local Sunrise Times (EST)
January 7:45
February 7:30
March 6:45
April 6:15
May 5:30
June 5:30
July 5:30
August 6:00
September 6:15
October 6:45
November 7:15
December 7:30
Monthly Local Sunset Times
January 5:45
February 6:15
March 6:45
April 7:15
May 7:30
June 7:45
July 7:45
August 7:30
September 6:45
October 6:00
November 5:30
December 5:30

Monthly Local Sunrise Times (EDT)
January 8:45
February 8:30
March 7:45
April 7:15
May 6:30
June 6:30
July 6:30
August 7:00
September 7:15
October 7:45
November 8:15
December 8:30
Monthly Local Sunset Times
January 6:45
February 7:15
March 7:45
April 8:15
May 8:30
June 8:45
July 8:45
August 8:30
September 7:45
October 7:00
November 6:30
December 6:30

For WPTF, it's the following during EST (add one hour for EDT):

Monthly Local Sunrise Times
January 7:30
February 7:00
March 6:30
April 5:45
May 5:15
June 5:00
July 5:15
August 5:30
September 6:00
October 6:15
November 6:45
December 7:15

Monthly Local Sunset Times
January 5:30
February 6:00
March 6:15
April 6:45
May 7:15
June 7:30
July 7:30
August 7:00
September 6:30
October 5:45
November 5:15
December 5:00

 

[RadioDoogie]

I know that if you drive under those high voltage lines along Pleasant Hill (also in Gwinnett), many times 680 will swamp the AM dial.

I'm guessing the NW nulls are to protect WMFS out of Memphis, which has the feet of a snow-angel night pattern in the northern half of Mississippi. https://radio-locator.com/info/WMFS-AM

In addition to WPTF, there's also WCTT in Corbin, KY, in the big NE null. It's a tiny class B, but they actually have more licensed power at night. https://radio-locator.com/info/WCTT-AM
Also in the NE null is another tiny class B, WHBE. https://radio-locator.com/info/WHBE-AM

Why does WCNN need protection from WMFS if they are both not full power (clear channel) signals? I understand the transmitter having a null towards WPTF since it is full power day/night. I’m not a technical guy so can the low power signals of WCNN and WMFS still travel that far at night? On a side note on the FM side, there are no 99.7FMs between here and Memphis due to full power 100kw WWWQ here and grandfathered power 300kw WMC. That’s a large 400 mile distance between two FM stations.

 

[davideduardo]

Why does WCNN need protection from WMFS if they are both not full power (clear channel) signals? I understand the transmitter having a null towards WPTF since it is full power day/night. I’m not a technical guy so can the low power signals of WCNN and WMFS still travel that far at night? On a side note on the FM side, there are no 99.7FMs between here and Memphis due to full power 100kw WWWQ here and grandfathered power 300kw WMC. That’s a large 400 mile distance between two FM stations.

WCNN protects 680 in Memphis because the Memphis station was there first.

New stations going on the air have to protect existing stations, no matter what class they are.

At night, skywave signals travel great distances, and stations hundreds and hundreds of miles away can interfere with the local reception of other stations unless they comply with the protection rules.

My favorite example of how far AM stations can go is the case of listening to WSM sign off at midnight, CST, one Monday morning loooong ago. Without adjusting the volume, WSM was replaced by KORL in Homolulu, a 10 kw station. And I was in Cleveland, Ohio!

Another case, and one widely reported in the eastern US back about 60 years ago was tuning for Seattle on 1090, only to find CX-28 in Uruguay pounding in with its 10 kw signal.

The laws of physics have not changed. AM signals still travel just as far, and they are immensely capable of interfering with the reception of local stations.

Final example. With what is today WTAM in Cleveland (a full 50 kw clear channel station) on the air at just 25 miles from me, I had a 10 kw station from the interior of Venezuela at nearly equal levels due to extreme fall auroral conditions.