Can You Hear 900 XEW from Mexico City?

[Gregg.]

XEW has the distinction of being the highest powered AM radio station in North America... 250,000 watts, non-directional. In a separate thread about superpower AM stations, I wondered if that station is still operating at that power. David says he was inside the XEW transmitter some years ago and he thinks it's still running at a quarter million watts. But for a station running five times what the biggest U.S. stations run, I don't think it gets heard that well around North America.

I've never heard XEW. Of course, I'm in the Northeast. 900 CHML, 50,000 watts from Hamilton, Ontario, comes in most nights by me, sometimes quite strongly. But I have heard other Mexican stations on occasion. I remember being on the Delaware Memorial Bridge between Delaware and New Jersey one night, hearing a Spanish-language station fighting with KYW Philadelphia on 1060, only 30 miles away. I assume that was XEEP Mexico City, the other Class A on that frequency.

XEW is the flagship for the W Network in Mexico, a News/Talk network owned by Televisa. But it is simulcast on XEW-FM and many of the shows are heard on other Televisa stations on the W Network around Mexico, including 690 XEWW Tijuana, which blankets Southern California. So I wonder if Televisa still wants to pay that hefty electric bill for programming that can be heard on FM in the capital and on other AM stations around the country.

 

[radioman148]

I can still hear XEW in the Chicago area late at night, but not as well as many years ago. I don't know if it's their power or more interference that we all have to deal with on the AM band these days.

 

[davideduardo]

XEW has the distinction of being the highest powered AM radio station in North America... 250,000 watts, non-directional.

The 1180 station in Cuba is nominally 300 kw, but the higher power Cuban stations tend to be erratic in the use of their full facilities.

In a separate thread about superpower AM stations, I wondered if that station is still operating at that power. David says he was inside the XEW transmitter some years ago and he thinks it's still running at a quarter million watts. But for a station running five times what the biggest U.S. stations run, I don't think it gets heard that well around North America.

XEW was never a skywave blaster in the US. An easy log before lots of night interference on the channel, yes. But they optimized the facility long ago for skywave suppression to avoid groundwave cancellation effects at night in the area immediately around Mexico City, home to about a third of the country's population.

Then, as AM lost its ratings power several decades ago they allowed the construction of a sports complex for the professional soccer teams that the previous owner owned.

I've never heard XEW. Of course, I'm in the Northeast. 900 CHML, 50,000 watts from Hamilton, Ontario, comes in most nights by me, sometimes quite strongly. But I have heard other Mexican stations on occasion. I remember being on the Delaware Memorial Bridge between Delaware and New Jersey one night, hearing a Spanish-language station fighting with KYW Philadelphia on 1060, only 30 miles away. I assume that was XEEP Mexico City, the other Class A on that frequency.

XEEP is what used to be a 1-B clear. It's directional to protect KYW, the other 1-B. This is similar to the relationship of KRLD and WTIC on 1080.

XEW is the flagship for the W Network in Mexico, a News/Talk network owned by Televisa.

The network is not owned by Televisa. It is owned by Grupo PRISA from Spain. XEW itself is owned by a partnership between PRISA and Televisa, with management all done by PRISA. While the group is called "Televisa Radio" Televisa does not operate it and does not have a controlling position in it.

But it is simulcast on XEW-FM and many of the shows are heard on other Televisa stations on the W Network around Mexico, including 690 XEWW Tijuana, which blankets Southern California.

XEWW may blanket San Diego County, but in Imperial COunty to the east is is not a good signal. SImilarly, it is OK in much of Orange County, but inland in LA County it is fairly useless. That's why it seldom gets more than a 0.1 share in the LA metro. XEWW is a pure PRISA play, as they even tried to use the signal to be an LA station, which was a monstrous failure.

So I wonder if Televisa still wants to pay that hefty electric bill for programming that can be heard on FM in the capital and on other AM stations around the country.

There are any number of AMs in Mexico city with high power that get low ratings (The "W Radio" net gets nearly no listenership). Except for a couple at the high end of the dial that are silent for financial reasons, there are 23 AMs in Mexico City with 50 kw or over... the power is needed to overcome the horrible man made noise in that city which now has 25,000,000 people in the metro area.

 

[mimo]

I get XEW from time to time here in Ottawa. CHML sends it's signal to the east at night, but we are north east of them, so the lobe doesn't hit us very hard. In Toronto, I have heard XEW take CHML right off the dial at night. CHML doesn't target Toronto at night, so while it is listenable, it can be easily taken out. When I lived in the midwest, XEW was a non factor north of the town I lived in, and wasn't very clear sometimes. Other times it was a blaster. This was just north of the Iowa/Missouri state line. Once you crossed into Missouri, the signal greatly improved.

 

[Ai4i]

...that city which now has 25,000,000 people in the metro area.

Would it then be fair to say that NYC is only the #2 media market by population in North America?
I think Mexico is considered part of this continent.

1. Mexico City
2. N.Y.C.
3. L.A.
4. Toronto
5. Chi-town

 

[davideduardo]

Would it then be fair to say that NYC is only the #2 media market by population in North America?
I think Mexico is considered part of this continent.

1. Mexico City
2. N.Y.C.
3. L.A.
4. Toronto
5. Chi-town

Mexico is indeed in North America.

If you go to a hemisphere level, then the biggest cities are Mexico City, Buenos Aires, Sao Paulo and then New York.

 

[schmave]

I have never heard XEW here in Ohio, nor have I heard the other Mexican stations I used to take for granted back when I lived in Houston - 730 XEX out of Mexico City, 1050 XEG from Monterrey and 1570 XERF from Ciudad Acuna.

 

[rbrucecarter5]

For some reason, it used to seem a lot more powerful than it is today.

 

[Mediafrog+]

For some reason, it used to seem a lot more powerful than it is today.

XEW would boom in clearly all over Texas at night a few decades ago, even in the Panhandle. Of course there were several Mexico City AMs that were easy to hear as well, such as XEX, XEQ, and XEB among others.

I was able to hear XEW with a listenable signal during a visit to Grand Teton/Yellowstone National Parks in the late 1960's.

Nowadays XEW is lost in the co-channel pileup on 900, and either is running much less than 250kw, or has changed the antenna system to reduce skywave.

 

[davideduardo]

Nowadays XEW is lost in the co-channel pileup on 900, and either is running much less than 250kw, or has changed the antenna system to reduce skywave.

Years ago the site was a piece of the dried Lake Texcoco coastal plain, but as the lake has dried further, the ground water level has declined. And then the area used to be rural semi-arid desert. Now there are over a million people all around the transmitter and they even built a sports complex over the ground system. It's just not an efficient site any more.

 

[cyberdad]

Years ago the site was a piece of the dried Lake Texcoco coastal plain, but as the lake has dried further, the ground water level has declined. And then the area used to be rural semi-arid desert. Now there are over a million people all around the transmitter and they even built a sports complex over the ground system. It's just not an efficient site any more.

Thanks, as always, for your insights and explanations. My experience with XEW fits in with what you and others have posted. For me in the Chicago area, XEW is still doable, but far less reliable than it used to be. And, by no means, was it ever a powerhouse. Also, I didn't realize XEEP was directional to protect KYW and vice versa...although, that makes perfect sense. I hear XEEP from time to time at home in the Chicago area, but it's far from reliable. But here in the Tampa Bay area, where I am for the next two weeks, if anything, XEEP is an easier catch than XEW.

 

[Sammi Brie]

There are any number of AMs in Mexico city with high power that get low ratings (The "W Radio" net gets nearly no listenership). Except for a couple at the high end of the dial that are silent for financial reasons, there are 23 AMs in Mexico City with 50 kw or over... the power is needed to overcome the horrible man made noise in that city which now has 25,000,000 people in the metro area.

Yeah, AM is in really bad shape. José Gutiérrez Vivó had no business sense, but Radio Trece's loss is probably more indicative.

I'm probably out of range. On the only frequency that's good (HD locals on 910 and 1230 so no 900 and 1220), 730, I instead got XEGDL (Guadalajara).

 

[Gregg.]

David said >>>they optimized the facility long ago for skywave suppression to avoid groundwave cancellation effects at night in the area immediately around Mexico City, home to about a third of the country's population.<<<

I didn't know an owner could optimize a high power AM station for skywave suppression. I have heard that sometimes it's hard to hear a high power station 50-100 miles away from the transmitter at night because the skywave is fighting with the groundwave signal, arriving at your radio a split-second apart. But I never heard that engineers could do anything about it. And I don't think I've ever experienced it, or at least I didn't recognize it while listening.

 

[schmave]

How is the ground conductivity around Mexico City? Earlier in this thread the high noise levels within the city itself were mentioned, but I am wondering more about the outlying areas 50-100 miles away? If there's good conductivity, that cancellation zone should be much farther than 50 miles I would think, unless the signal is considerably weakened by all the noise in Mexico City.

 

[davideduardo]

How is the ground conductivity around Mexico City? Earlier in this thread the high noise levels within the city itself were mentioned, but I am wondering more about the outlying areas 50-100 miles away? If there's good conductivity, that cancellation zone should be much farther than 50 miles I would think, unless the signal is considerably weakened by all the noise in Mexico City.

The Valley of Mexico is alluvial soil, with underground moisture. It tends to have decent conductivity. But the city is ringed by volcanic origin mountains where conductivity falls off fast.

 

[davideduardo]

How is the ground conductivity around Mexico City? Earlier in this thread the high noise levels within the city itself were mentioned, but I am wondering more about the outlying areas 50-100 miles away? If there's good conductivity, that cancellation zone should be much farther than 50 miles I would think, unless the signal is considerably weakened by all the noise in Mexico City.

The electrical height of a tower determines the angle of radiation of an antenna. Quarter wave antennas tend to have a higher angle of radiation. Half wave is much lower, with a better groundwave field. Going to a 5/8 wave antenna will lower the angle more, but create a secondary high angle lobe... but that will not come down to earth close by.

That is a really simplified explanation; I have never designed a station with groundwave optimization so I am just giving a thumbnail idea of how this can be managed.

The issue is the cost vs. desirable ground coverage.

 

[pianoplayer88key]

The electrical height of a tower determines the angle of radiation of an antenna. Quarter wave antennas tend to have a higher angle of radiation. Half wave is much lower, with a better groundwave field. Going to a 5/8 wave antenna will lower the angle more, but create a secondary high angle lobe... but that will not come down to earth close by.

That is a really simplified explanation; I have never designed a station with groundwave optimization so I am just giving a thumbnail idea of how this can be managed.

The issue is the cost vs. desirable ground coverage.

David, what about antennas like what KFBK and KSTP use, and possibly (if maybe to a lesser extent) WHO? And besides the obvious vast difference in wavelength, how would it compare or contrast with multi-bay FM and TV antennas?

Also what are typical efficiencies, if you could call it that, of various common FM/TV antenna systems, in terms of mV/m at 1 km for 1 kW of transmitter power? For example on AM I understand that a 1/4-wave is about 306 mV/m, 1/2-wave about 381 mV/m, and Franklin like KFBK/KSTP is about 512 mV/m or so. What about FM, like 4, 6, 8-bay antennas, etc, or whatever is commonly used? (Am I correctly assuming that a 1 kW ERP (not confusing it with TPO) refers to 305.78 mV/m at 1 km, like from a 1/4-wave AM tower & ground plane? Or is it ~381 mV/m like from a 1/2-wave AM?)

 

[davideduardo]

David, what about antennas like what KFBK and KSTP use, and possibly (if maybe to a lesser extent) WHO? And besides the obvious vast difference in wavelength, how would it compare or contrast with multi-bay FM and TV antennas?

I am not familiar with the skywave characteristics of a Franklin antenna.

In the KFBK case, it extends the coverage at that awful 1530 frequency considerably. A Franklin is essentially a verticle half-wave dipole, insulated in the middle. Due to the resultant height, I've only seen them used at high frequencies. Another was KELO in Sioux Falls, 1320 AM.

Any Franklin that is not two half-wave antennas is going to be less efficient.

A true Franklin (180 over 180 degrees; 360 degrees, total) has an efficiency of about 510 mV/m/kW at 1 km. A pseudo-Franklin (180 over 120 degrees; 300 degrees, total) has an efficiency of about 470 mV/m/kW at 1 km. Another pseudo-Franklin (120 over 120 degrees; 240 degrees, total) has an efficiency of about 430 mV/m/kW at 1 km.

A Franklin at 570 kHz would be about 570 meters high... over 1800 feet high.

 

[boombox4]

Never heard XEW here at my location in the Seattle metro. I have heard the Mexico City station on 1500 khz -- a few years ago, on a boombox.

 

[Ai4i]

The tallest broadcast radiator to have ever existed was the "Warsaw Radio Mast",
located near Konstantynow, Gabin, Poland.
Construction was completed in 1974, but it collapsed in 1991.
At 646 meters (2,121 feet) tall, it was just under a halfwave at 227 and 225 KHz.
Only Burj Khalifa is taller.
Optimizing this radiator for groundwave coverage would
have required something between a kilometer and a mile high.

The tallest Blau-Knox "Diamond" tower is the 314 meter (1030 foot)
Lakihegy Tower at Szigetszentmiklós-Lakihegy, Hungaru.
The tallest one in the United States is WSM's 246 meter (808 foot)
halfwave, in or near Franklin, TN.
WBT uses three 130 meter (428 foot) halfwaves near Charlotte, NC.
WBT radiates up and down the east coast but away from KFAB, Omaha, NE.