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1st adjacent AMs with significant daytime overlap of their 2.5 mV/m contours

J

joebtsflk1

Only about 40 miles separate 1230 KKPC Pueblo and 1240 KRDO Colorado Springs.  They seem to coexist fairly well.  But unlike similar allocations in poor ground conductivity areas, the Front Range east of the mountains is fairly good, so there is considerable overlap of the 2.5 mV/m red circles on Radio-Locator.

And for "solely entertainment purposes" here are their daytime maps

KKPC: http://radio-locator.com/cgi-bin/pat?call=KKPC&service=AM&status=L&hours=D

KRDO: http://radio-locator.com/cgi-bin/pat?call=KRDO&service=AM&status=L&hours=D

Any other similar "too close for comfort" neighbors?  Omaha's 590 KXSP and Topeka's 580 WIBW come to mind, but in percentage overlap terms, KKPC vs. KRDO is greater.
 
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Joe:
There was a similar thread about CO-channel stations a while back. Of course, the thread deteriorated/advanced into other tangents because everyone within range of some provincial conflict jumped in.

The noisiest topic on the commotion, involving what I guess were the most people per square mile, was the 1340 situation vis-a-vis WRAW 1340 Reading PA, WHAT 1340 Philadelphia, and WMID 1340 Atlantic City. Talk about short-spacing!
Yet, there turned out to be little overlap. That allowance obviously goes back decades, when those three stations were 250-watters.

Here's poor WHAT, the middle station geographically.
http://www.radio-locator.com/cgi-bin/pat?call=WHAT&service=AM&status=L&hours=U

Both Reading and Atlantic City are on their coverage map!

Another potential joust -- another 1967 cage-match -- was between WDLC Port Jervis NY and WKNY Kingston NY.
Absolutely no overlap. In 1967 and now.

My favorite was the nee WALE 1400 in Fall River MA (a 1000-watt graveyarder) and WBSM 1420 New Bedford (5000 watts during the day). the two downtowns are maybe 10 miles from each other.
http://www.radio-locator.com/cgi-bin/pat?call=WBSM&service=AM&status=L&hours=D
 
Nothing like really bad ground conductivity to really pack stations in tight. You're right about the former 250 watt graveyarders that were adequately spaced become overlapping neighbors at 1 kW. I'm guessing the 1st adjacent overlaps occurred the most between 1230 and 1240 with the more relaxed interference standards for class C stations.
 
Thanks for the "entertainment", Joe. The first thing I thought of was WSBC (1240) in Chicago, and WJOB (1230) just outside Chicago city limits in Hammond, IN. So purely for entertainment purposes, I checked. Sure enough, these two overlap 2.5 mV/m contours in downtown Chicago and on the near south side. I'm sure in the long history of each stations there've undoubtedly been issues of one sort or another, but I'm personally not aware of any significant controversy.

(BTW: All joking aside, I'm a big fan of the services provided by radio-locator. We all know they're not perfect, but given the scope of what their mission is, I think they do a very creditable job.)
 
I ran through my daily allotment of Radio Locator (I get why they have limits!) trying to find some snug 1230s and 1240s. Forgot how close Hammond is to Chicago...I wanted to place it around Elkhart...band instruments and organs go together, don't they?

Snooped about the FCC AM regs regarding prohibited overlap, and indeed, when it comes to C's, there isn't really any hard or fast rules, courtesy of these subsections of 73.37:

(b) In determining overlap received,an application for a new Class C stationwith daytime power of 250 watts,or greater, shall be considered on theassumption that both the proposed operationand all existing Class C stationsoperate with 250 watts and utilizenon-directional antennas.

(c) If otherwise consistent with thepublic interest, an application requestingan increase in the daytime power ofan existing Class C station on a localchannel from 250 watts to a maximumof 1kW, or from 100 watts to a maximumof 500 watts, may be granted notwithstandingoverlap prohibited byparagraph (a) of this section. In thecase of a 100 watt Class C station increasingdaytime power, the provisionsof this paragraph shall not be construedto permit an increase in powerto more than 500 watts, if prohibitedoverlap would be involved, even if successiveapplications should be tendered.
 
Two sets of 1230/1240 close calls in central and northwestern Illinois:

WFXN-1230 Moline, IL and WSDR-1240 Sterling, IL:

WFXN: http://radio-locator.com/cgi-bin/pat?call=WFXN&service=AM&status=L&hours=U
WSDR: http://radio-locator.com/cgi-bin/pat?call=WSDR&service=AM&status=L&hours=D

WJBC-1230 Bloomington, IL and WTAX-1240 Springfield, IL:

WJBC: http://radio-locator.com/cgi-bin/pat?call=WJBC&service=AM&status=L&hours=U
WTAX: http://radio-locator.com/cgi-bin/pat?call=WTAX&service=AM&status=L&hours=U

Per Radio-Locator (FWIW), the "distant" signals for WJBC and WTAX either include or reach the outskirts of the other COL's city limits. Yet WJBC slop wreaks havoc on WTAX's signal from Lincoln northward, and it was worse when WJBC had IBOC.

In addition, WFXN and WJBC rotate back and forth on 1230 between Galesburg and Peoria.
 
Some of those rules, particularly the one concerning heritage call stations KGFJ and 100 watt KPPC, limiting KPPC to an increase to 500 watts, came about in the early 1980s as I recall.

If you can prove that the conductivity is much less than M-3, you can squeeze them in closer. In many cases it is.

To this day, WSBC operates with minimum Class C efficiency of about 241 mV/m, even though it is licensed with a grandfathered 1000 watt nominal power. As it uses a tower about 90 degrees high, you know the input is less than 1000 watts to the tower. At one time, they used a Series Limiting Resistor, after which they were allowed to reduce power to the tower and get rid of the SLR/LIN Resistor/Efficiency Resistor. This was done during the first "energy crisis" when it was argued that the SLRs wasted energy, which unless someone came up with creative ways to use the heat, they did. Anyone know of anyone heating a transmitter shack or heating water with the SLR heat?
 
The noisiest topic on the commotion, involving what I guess were the most people per square mile, was the 1340 situation vis-a-vis WRAW 1340 Reading PA, WHAT 1340 Philadelphia, and WMID 1340 Atlantic City. Talk about short-spacing!
Yet, there turned out to be little overlap. That allowance obviously goes back decades, when those three stations were 250-watters.
Click to expand...

Steve, that brings back memories of my early DXing days growing up in South Jersey near Philadelphia.

I always liked to hear WMID when we would go down to the shore and I remember when we would sometimes stop somewhere in the Pine Barrens on Route 72 (if we were going to Beach Haven) or on the AC Expressway or Route 30 (if we were going to Atlantic City) and I would get out my radio to hear how strong WMID was.

Back home, it was WHAT during the day but I still could hear a very weak WMID way in the background.

Here's Radio Locator's map for WMID which I think is a bit conservative on their 'fringe' estimate.

http://radio-locator.com/cgi-bin/pat?call=WMID&service=AM&status=L&hours=U


When we would visit friends in Massapequa, Long Island, WMID had a good signal in the daytime.

One reason I liked to listen to them was because they used to have the same American Contemporary Network sounders as WABC which I thought was neat.

From what I remember, in the 70's these graveyard stations were 1000 watts daytime and 250 watts at night.
 
Good observation about 1230 and 1240 being right next to each other, Joe. I had not until you mentioned it realized -- in over 50 years of DXing -- that those two were the only GY pair adjacent to each other.

1230 WFAS White Plains NY and 1240 WGBB Freeport Long Island can't be that much more than 25 miles from each other.
Here's WFAS. Freeport is on the same coverage map, hi.
http://www.radio-locator.com/cgi-bin/pat?call=WFAS&service=AM&status=L&hours=U

We lived near the 'k' in the word New York'. Neither the closer WGBB nor the farther WFAS splashed onto one another.

* * * * * * * *

Right about WMID and Long Island, Gar.
MJ Rosenbluth, one of the guys on what we call 'Riccio's Oldies Board' remembers when it was WABC, WMID and then WGBB as summer music choices on Jones Beach. That water path from WMID -- again, us DXing from near the 'k' in New York -- sometimes could make for WMID splashing onto New York City-licensed WPOW !

Re Massapequa ....
Ah, yes.
I was like 10 when one of the relatives moved to a new house in Massapequa PARK. That was like a suburb of Massapequa. Their street hadn't even been finished ; it was dirt for another few blocks. Nowadays, anyone under a certain age wouldn't be able to look at the place and calculate any other geological reference other than that it must have gone up around the same time as the Pyramids.
Great water-path DX spot Mass. Park was, too. Thanks for the memories, Gar!
 
gar fla said:
From what I remember, in the 70's these graveyard stations were 1000 watts daytime and 250 watts at night.
Click to expand...

Exactly what I remember. Great posts from you and Steve. Interesting what happens when you have a salt water path next to areas of less than ideal ground conductivity.

And Tim, your observations are pretty much in line with my experiences have been. I think the "problem" with short-spaced graveyard stations in the Illinois-Iowa area is that they were not short-spaced at 250 watts, but that changed when the limits went up to 1,000 watts. Station owners and managers undoubtedly realized an improved local signal was worth having overlap in fringe areas.
 
I don't know the specs for both stations...but do these two count?

WILI-AM 1400 Willimantic, CT (northeast CT in Windham County)
WPOP-AM 1410 Hartford, CT

I believe WPOP-AM is a 5,000 watt station with a directional pattern. Their transmitter is off of Cedar Street (CT Route 175) in Newington, CT.
 
cyberdad said:
Exactly what I remember. Great posts from you and Steve. Interesting what happens when you have a salt water path next to areas of less than ideal ground conductivity.

And Tim, your observations are pretty much in line with my experiences have been. I think the "problem" with short-spaced graveyard stations in the Illinois-Iowa area is that they were not short-spaced at 250 watts, but that changed when the limits went up to 1,000 watts. Station owners and managers undoubtedly realized an improved local signal was worth having overlap in fringe areas.
Click to expand...

1490 is another crazy overlap situation in northwestern Illinois, this time involving 3 signals: KBUR Burlington, IA; WZOE Princeton; and WDBQ Dubuque, IA.

KBUR: http://radio-locator.com/cgi-bin/pat?call=KBUR&service=AM&status=L&hours=U

WZOE: http://radio-locator.com/cgi-bin/pat?call=WZOE&service=AM&status=L&hours=U

WDBQ: http://radio-locator.com/cgi-bin/pat?call=WDBQ&service=AM&status=L&hours=U

And to top this one off, the now-dark (since about 2003) WGEN Geneseo, IL--37 miles west of Princeton--was a daytimer on 1500 (250 watts IIRC).
 
A 1450 example in my old (growing up) and new (current city) backyards: WKEI Kewanee, IL and WFMB-AM Springfield:

http://radio-locator.com/cgi-bin/pat?call=WKEI&service=AM&status=L&hours=D

http://radio-locator.com/cgi-bin/pat?call=WFMB&service=AM&status=L&hours=U

In spite of what Radio-locator shows, of the two stations you can hear WKEI clearer in Canton, IL (Fulton County), with WFMB barely audible underneath.

And both 1450s are interesting in that they are part of the MLB radio networks for a team whose COL can be considered part of the rival's home territory (based on fan percentages): WKEI is a Cardinal affiliate in primarily Cubs territory (Henry County, IL), and WFMB-AM carries Cub baseball from a stick (in the municipality of Southern View in the south part of Springfield) about 90 miles from Busch Stadium (and can be barely heard on a car radio in parts of the St. Louis suburbs). Springfield does have a strong Cub fan presence, but the Cardinals presence and fandom is much stronger.
 
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Another example could be in the I-91 corridor to my north:

WHLL-AM 1450 Springfield, MA - 1,000 watts [transmits from Springfield, close to the US Route 20 bridge on the Connecticut River]
WTSA-AM 1450 Brattleboro, VT - 1,000 watts unlimited [transmits from the north end of town, off of US 5/VT 9, near the mouth of the West River]

Springfield, MA to Brattleboro, VT in a straight line is 52 mi/83 km
 
@ KML ....

Wow, I hope I'm not overposting here, but these 'GY Memories' are too ripe to ignore. And with the current tragic condition of AM (plus considering that GY stations are probably the lowest form of media life) only the devil knows how many nostalgic posts remain.

See, I once worked across the hall from 1450 Springfield MA. I was at their AoR little sister on 94.7 -- Heavy FM -- while the AM 1450 was WMAS. They were country at the time. But I'd do news for a few casts in the afternoon on WMAS because they liked how I read news, for some reason. I filled in doing a C&W show once on WMAS, and once even filled in doing a SOUL show one Saturday night. Wow, talk about train-wreck programming.
WHVY-FM developed into the bigger station by far, starting in 1972. We were a bunch of kids and hippie wannabees playing progressive rock for peon wages and the next thing you know, WHVY was shoving market mainstay WHYN 560 into the Connecticut River.

At the time, there was emerging a lot of crossover material, 45's, between AoR and Top 40. My Brooklyn buddy Harry Mankin and I were on opposite each other from 7-mid, he on WHYN and me on WHVY. We used to drive our respective program directors nuts by pre-arranging on the studio phones to come out of the 9:00 hour with the same songs in the same sequence -- all within the respective formats.

Ah, yeah. I still remember the self-supporting WMAS 1450 tower outside the studio parking lot. It also housed WHVY 94.7.

Back to my pipe, slippers and brandy .......
 
Steve. I had no idea you were a pipe smoking, brandy drinking, slippers wearing, hippie.

And I thought I was the only one. :)
 
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Somewhat OT, inspired by Steve Green's comment about current tragic AM condition and GY being lowest media life:
When was the last time a GY station was rated #1 in a market with a population in the main city over 350k, or whose city area in square miles was larger than the GY's official (5 mV/m per FCC, I believe) local coverage area? (Don't include saltwater coverage.)

Or if never, what's the closest they've come, or the largest city that had a #1 GY station? (Minimum at least 7 other AM stations with a 5 mV/m or greater signal in the area.)

Back on topic:
I think 1030 XESDD and 1040 KURS have significant overlap. There are places especially in south San Diego where both of them have significant overlap, and even at my house east of La Mesa I think KURS is around 6-8 mV/m and XESDD about 2.5-3 mV/m or so. (Ignore XESDD's pattern on radio-locator - they're operating non-directional.)

For co-channel overlap, I'd nominate 1390 XEKT and KLTX. (Radio-locator claims XEKT is on 1380, which is false.) In some places in coastal San Diego area, the two stations have a fairly strong clash that, while I haven't tested recently, I believe would stop a scan on a radio with that function.

I think an example of the ultimate co-channel overlap would be to have the other station's signal audible at the one station's transmitter site in the middle of the day, at least during fleeting periods of dead air like in a talk show between sentences. Does anyone know of any real-world situations that come close, without including mid-winter skywave?
 
pianoplayer88key said:
Somewhat OT, inspired by Steve Green's comment about current tragic AM condition and GY being lowest media life:
When was the last time a GY station was rated #1 in a market with a population in the main city over 350k, or whose city area in square miles was larger than the GY's official (5 mV/m per FCC, I believe) local coverage area? (Don't include saltwater coverage.)

Or if never, what's the closest they've come, or the largest city that had a #1 GY station? (Minimum at least 7 other AM stations with a 5 mV/m or greater signal in the area.)

Back on topic:
I think 1030 XESDD and 1040 KURS have significant overlap. There are places especially in south San Diego where both of them have significant overlap, and even at my house east of La Mesa I think KURS is around 6-8 mV/m and XESDD about 2.5-3 mV/m or so. (Ignore XESDD's pattern on radio-locator - they're operating non-directional.)

For co-channel overlap, I'd nominate 1390 XEKT and KLTX. (Radio-locator claims XEKT is on 1380, which is false.) In some places in coastal San Diego area, the two stations have a fairly strong clash that, while I haven't tested recently, I believe would stop a scan on a radio with that function.

I think an example of the ultimate co-channel overlap would be to have the other station's signal audible at the one station's transmitter site in the middle of the day, at least during fleeting periods of dead air like in a talk show between sentences. Does anyone know of any real-world situations that come close, without including mid-winter skywave?
Click to expand...

I would think that Class IV/Class C cochannel stations could be heard frequently with a good radio at the site of the closest cochannel station when it was off the air. In my area, when there was a major power outage in the NE in 2003 and WQBH 1400 Detroit was off the air, WSAM 1400 Saginaw was clearly receivable less than 20 miles away from WQBH's transmitter. At night, many stations hear cochannel stations on their off air monitor. It depends on the DA pattern, which becomes the receiving antenna pattern. With the off air monitor on after WAAM 1600 Ann Arbor signed off, WWRL 1600 New York City was frequently blaring in with the WAAM day pattern antenna.

Some engineers here probably have similar stories we would like to hear.
 
That's interesting, SC. :) I've also heard stories of being able to hear class A stations underneath Class D with night flea power stations at night, while the D is on the air, at their transmitter site.
I was mostly thinking about daytime situations though. :) Maybe some overlapping class C stations could do it, maybe even during dead air periods when the station < 25 meters away is on the air with an unmodulated carrier.

I wonder if it's ever happened at class A stations' transmitter sites, though? Or, even with the one class A off? I think a couple ultimate examples would be to be able to have a listenable signal on CBK at XEWA's transmitter site, or on CKWX at XEROK's transmitter site (or any other two co-channel Class A stations, like KNZR at WFME) when the nearby station is off, using a radio the size & form factor of the DT-400W or SRF-59 at noon CDT in June during solar maximum, but that'd be more of a testament to spectacular sensitivity for that size radio than signal overlap.

And, what are some situations, if any, where another station's day pattern, operating under licensed parameters, at some times of the year puts a greyline / sunset/rise skywave signal into the COL (or 10+ mV/m groundwave contour) of a Class A station that's strong enough to cause co-channel fluttering and/or be clearly understandable under (or with) the class A station? (For example, take a theoretical class A on, say, 1530 or 1560, and a class D about 300 to 400 miles west, with a narrowly-focused 6 or more tower day pattern aimed east. The close distance would be due to an average ground conductivity of 1 mS/m or lower between the two stations.)
 
Haven't heard of the cochannel station being heard at a site unless the station at the site is on night power <20 watts with no modulation. WKJR 1520 Muskegon Heights was 10/1 U4 with a nine tower array, and you could hear WCKY 1530 Cincinnati on the lot where the towers were with WKJR at full night power. As I recall, both stations were owned by Pathfinder Communications at the time, and it was a curiosity for the corporate and local station engineers. Sometimes, they leave an exciter on at a Class D station on a Class A Clear Channel freqeuncy, and you can hear the modulation through the unmodulated exciter carrier. Does anyone know what the exciter power output level would be? I still don't think they are supposed to leave the exciter going to the antenna, but it really doesn't cause much interference. I have heard both AM and FM stations that were off the air with their exciter on. I lived a mile from an FM station that signed on at 6:00 AM that I used as an alarm clock. I knew the night DJ who signed it off at midnight, and asked why it took an hour or more after the station signed off to turn the transmitter off. He explained that he could turn the intermediate and power amplifiers off from the DJ booth, but waited until he left the building to turn the exciter off in the transmitter room. He demonstrated another time how that unless you turned the microphone pot all the way down, you could hear all the sounds in the studio over the air. In those times before station liability issues prevented the DJ from allowing any visitors in the studio, I'm sure there were some very odd things that went out over the air if stations had the exciter on and the mike potted up. Perhaps some radio veterans here have more of these types of stories they could relate. At that same station, they did a non simulcast call in talk show on the AM in the other studio. When the AM sign off cart was played from that studio at sundown (the station was a daytimer then), if the phone line pot was not turned down, you could hear phone calls that came in on that line on the AM station before the transmitter was turned off.
 
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