WJYM (the long-ago WMGS, King Country 73) was a daytimer until it got night authorization. I can see them protecting Leamington still. I had forgotten about CHYR, they could be received on 710 in Fort Wayne with WLW nulled.
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AM Frequency of the Week: 710
- Thread starter cyberdad
- Start date
Once in Providence RI, I got Radio Capital out of Caracas, Venezuela without a trace of WOR which is the normal catch.
A question for you broadcast engineering folks. What could KCMO here in my area be protecting on 710 kHz with this unusual 5-tower daytime pattern?
KCMO-AM Radio Station Coverage Map
KCMO-AM Radio Station Coverage Map
Yes, there are scores, if not hundreds of stations that cannot meaningfully upgrade because of vacant allotments in Canada. Often a vacated allotment is close enough to the maximum directions that they would have to use four or more towers in a parallelogram and still have null toward the allotment. In rare cases, the allotment can be replaced with another frequency. This results in a narrow major lobe without a really good reason. There could have been restrictions also due to CHYR 710 second adjacent, and WVFN 730 East Lansing restrictions, even before CHYR7 went to 730 Nights in 1967, and until WJYM 730 was allowed Night power in the early 1980s. There was also a restriction against "Suburban" stations putting a 5 mV/m signal over the larger city (Toledo) at one time, back decades ago.
Unfortunately there are no applications I can find online which would include KCMO. In the past, there may have been Critical Hours restrictions toward WOR and KIRO. WDSM Duluth wouldn't be a problem either that I can see. Since the major first adjacents would have been WLW 700 and WGN 720, it doesn't look like that would have been a problem when it was authorized. Maybe some of the other posters who have a better familiarity with that area may have an answer. There might be a clue in the History Card. It will probably say WHB on it. Look it up as KCMO though.
KIRO and WOR would have been my guess.
WDSM is interesting. They are very directional to the north with their 5kw at night. I've driven by their transmitter site a number of times south of the Duluth-Superior metro. Mostly during the Kansas Citiy' 710's WHB days. At night, You only had to go about ten miles south of the WDSM sticks on U.S. 53 before WHB would completely own the channel.
They did some strange things as far as protection back then, like KGU 760 Honolulu, HI being Limited time and having to sign off to protect WJR 760 Detroit at "Night". It might have been some Critical Hours Plus protection of WOR and KIRO. When WKZO 590 Kalamazoo, MI wanted to go 5 kW Night, WOW 590 Omaha, NE tried to stop it for a long time. WKZO ended up having to be 5 kW DA from 6:00 PM EST to 10:00 AM each day to protect the de facto service area of WOW during all Critical Hours and Drive Time Hours all year long. This went on until May, 1968. WKZO didn't mind it much as it more than doubled their signal toward Grand Rapids, and at the time, not many people lived in the DA nulls around Kalamazoo. So maybe there was some sort of arrangement with WOR and KIRO for WHB to reduce IDF in the Daytime toward them.
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From NW San Antonio:
Day: Splatter from local 10 kW 720 KSAH. A few years back I caught a very weak KURV in Edinburg, TX, via groundwave at a nearby park with the help of a Terk loop.
Sunset: Amidst the splatter, KEEL is the first station to come up, followed later by R. Rebelde and then KGNC in Amarillo.
Night: KGNC is most dominant and the splatter is reduced. Aiming E/W, R. Rebelde usually has a fairly steady signal. Aiming NE/SW, XEMP "Radio 710" in Mexico City can be heard in and out, and KEEL somtimes comes up weakly.
Sunrise: KEEL is stronger, especially when it goes to day pattern/power. XEDP "La Ranchera" in Ciudad Cuauhtémoc pops up for a while when it goes to day power. Sometimes it airs a Christian program in a Germanic language, which must be for the Mennonite listeners in Chihuahua.
DX/Retro: I've only heard KCMO definitively with ID once. It was six years ago around 3 a.m.
Day: Splatter from local 10 kW 720 KSAH. A few years back I caught a very weak KURV in Edinburg, TX, via groundwave at a nearby park with the help of a Terk loop.
Sunset: Amidst the splatter, KEEL is the first station to come up, followed later by R. Rebelde and then KGNC in Amarillo.
Night: KGNC is most dominant and the splatter is reduced. Aiming E/W, R. Rebelde usually has a fairly steady signal. Aiming NE/SW, XEMP "Radio 710" in Mexico City can be heard in and out, and KEEL somtimes comes up weakly.
Sunrise: KEEL is stronger, especially when it goes to day pattern/power. XEDP "La Ranchera" in Ciudad Cuauhtémoc pops up for a while when it goes to day power. Sometimes it airs a Christian program in a Germanic language, which must be for the Mennonite listeners in Chihuahua.
DX/Retro: I've only heard KCMO definitively with ID once. It was six years ago around 3 a.m.
Yes, WDSM is interesting. It's supposed to be highly directional at night, but I've been hearing them here in eastern Iowa on a number of occasions the last few years. Related or not, I've also been hearing KDAL at night even more consistently.
I don't know if you had a specific direction in mind, but I was wondering if KXMR Bismarck might have something to do with it? I know KCMO looks like it's restricted somewhat in four different directions. The other three I don't have any idea about.
KCMO has a facility licensed in 1948. KXMR signed on in 2002. It looks like it just fit in to the pattern.
KXMR had been 50000 watts, so it would have been more critical then. Now it's 4000 watts.
Sometimes, there is no original reason for certain nulls, it's part of a symmetric pattern usually when there is no apparent reason. Sometimes, if you do complete Proofs of Performance, you find that you can let out nulls and otherwise change the Daytime Pattern, because the conductivity is much less than M-3.
KXMR had been 50000 watts, so it would have been more critical then. Now it's 4000 watts.
Sometimes, there is no original reason for certain nulls, it's part of a symmetric pattern usually when there is no apparent reason. Sometimes, if you do complete Proofs of Performance, you find that you can let out nulls and otherwise change the Daytime Pattern, because the conductivity is much less than M-3.
There are or were a few other considerations. Remember that at the time it was licensed, the nominal powers were 100, 250, 500,1000, 5000, 10000, and 50000. So they would have to be directional to concentrate the signal in some directions, they couldn't just raise the power to something like 15000 watts. There were also very strict considerations about co owned station overlap. Also, sometimes there were network exclusivity overlap considerations. So sometimes, the pattern had to protect those considerations.
That had been my understanding for quite some time (re: WHB on 710) before I became aware of their coverage map, which confirmed that. I think....but don't know for sure....that protecting WGN might have also been a consideration at one point. I listened to WHB (daytime) quite a bit at my college location in southeast Iowa, but WGN on the adjacent 720 had a somewhat stronger signal.
I never heard either one of them here until about six or eight months ago. Since then, I've heard KDAL a few times. WDSM only once.....at least that I can confirm. So I'm sort of wondering myself about what might be going on.
I've heard WDSM once quite awhile ago, but I haven't heard it lately in the Chicago area.
I am surprised no one has mentioned WAQI: the reduction must have done quite a number on them. I heard them once in Bowling Green, KY in late 1985 right before the pattern switch.
I was surprised how deep of a null they had a night. They were very shaky in Northern Broward County even with 50KW (heavily directional) 24/7.
I was surprised how deep of a null they had a night. They were very shaky in Northern Broward County even with 50KW (heavily directional) 24/7.
It's not just one station, it is about 10 stations, depending on the list you view. Cuba has put a plethora of stations on 710 to block the vehemently anti-Castro programming that used to be the mainstay of Radio Mambí in Miami.
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