Actual Mexican station technical facilities? (Wanting 2 plan rural day DX trip.)

[pianoplayer88key]

Does anyone know what the actual technical facilities of various Mexican stations are? As in, I'm thinking of transmitter coordinates, field strength at 1 km, taking into account the antenna efficiency and transmitter power, and where applicable directional pattern. (I believe I could calculate the FS if I have the pattern data and/or antenna efficiency & transmitter power.) I'm primarily interested in Mexican stations that put any trace of a signal into southern California or southwest Arizona, especially those with at least a 5 µV/m groundwave signal anywhere in San Diego or Imperial counties.

I'm wanting to calculate their signal strengths at several various rural locations, using the M3 map, and GW curves, or radio-timetraveller's field calculator program (in which case I would pick an average conductivity, or calculate for a range along the path, to get some general idea).

I'm wanting to plan another outing to a rural place sometime this spring or summer (the sooner the better) to see how my various portable AM radios perform when they're away from strong local stations, and the few places I've been the strongest signals are still too strong - for example 1390 XEKT, the strongest at Cameron Corners, is about 20-30 dB stronger there than I like. And of course we know how inaccurate the FCC, radio-locator, etc, are for data on Mexican stations. When I've checked at that location, or in Pauma Valley, I've sometimes had stations show up with a fairly strong signal that don't even show up on a radio-locator search.

I'd ideally like to find a place where even the strongest station won't trip the scan function, or indicates below 20 dBµ on my Tecsuns, or is below 200 µV/m groundwave, for example, preferably without having to travel too far as I would be going and coming back the same day. Some places I'm considering are Descanso, Pine Valley, Lake Cuyamaca, Julian, Santa Ysabel, Lake Henshaw, Boulevard, Jacumba, Borrego Springs (have been here once something like 10 years ago, but bus that goes there no longer goes & returns to San Diego the same day - only comes to San Diego in morning & returns to Borrego Springs in the afternoon), Anza, Niland, Newberry Springs, Ludlow (all in CA), or Wellton, AZ.

I'd be using a bus to get as close as the route will get me, then biking the rest of the way (I need to drop some weight anyway). (Of course if I'm able to get a $1k-3k car that gets > 25-35 mpg at 80+ mph by then that would change how far I'm willing to go, but I'd still be doing the round trip in one day.)


Is there any chance that our resident Mexican station expert, D.E., knows their technical parameters? Examples of stations I'm interested in include, but are not limited to ...

Tijuana area: 540 XESURF, 620 XESS, 690 XEWW, 800 XESPN, 860 XEMO, 950 XEKAM, 1030 XESDD, 1090 XEPRS, 1270 XEAZ, 1310 XEC, 1420 XEXX, 1470 XERCN, 1550 XEBG, 1630 XEUT, 1700 XEPE

Ensenada area: 730 XEEBC, 920 XESDA, 1010 XEDX, 1230 XESCT, 1400 XEPF, 1590 XEHC

Mexicali area: 790 XESU, 820 XEABCA, 850 XEZF, 910 XEAO, 940 XEWV, 990 XECL, 1050 XED, 1120 XEMX, 1150 XERM, 1190 XEMBC, 1340 XEAA, 1370 XEHG, 1590 XEYX

San Luis Rio Colorado area: 1080 XEDY, 1260 XEMW, 1350 XELBL, 1450 XECB, 1480 XEMCA, 1520 XEEH

Others: 1160 XEQIN San Quintin, 1390 XEKT Tecate


Also what's the ground conductivity in northwest Mexico like? Looking at KBLU's daytime coverage map (1 kW non-directional) implies it's much less than the USA side of the border:

but the fact that I hear 1160 XEQIN at Cameron Corners on a portable in spite of being something like 2-3x outside their predicted fringe contour on radio-locator, and don't hear USA stations that far outside their fringe much if at all, tells me the conductivity is higher than what the maps lead me to believe.

 

[davideduardo]

Unless there is information I have not found, I believe that the conductivity in Mexico used by mapping programs like Radio Locator is based on assumptions for comparable geography. I've never seen an equivalent map of ground conductivity for the SCT in Mexico such as the FCC has for evaluating US operations. There are a number of sources for estimated conductivity for the whole planet, based mostly on geology and predicted conductivity as opposed to measured conductivity.

Similarly, Mexico does not have an online database of predicted field strength at 1 km (or similar) of its licensed operations. With 85% of Mexican AMs set to disappear, I don't think they will be spending much time on any kind of AM data.

The FCC database is reasonable for border zone stations regulated via the process of the Comisión Mixta, but beware of the fact that Mexico likes to insert placeholders to freeze channels or to insert higher powers than licensed to assure greater protection for its stations.

That does not cover the issue, as once stated by a border broadcaster, that "Mexican watts are different from American watts".

 

[schmave]

When is the AM disappearance set to happen? I am curious to see how different the AM band will sound, even in the Midwest, when this happens. I can't imagine how different DX will be in Texas and anywhere else in the South.

 

[Icangelp]

When is the AM disappearance set to happen? I am curious to see how different the AM band will sound, even in the Midwest, when this happens. I can't imagine how different DX will be in Texas and anywhere else in the South.

I can't imagine it will be much different for us Ohioans. These days, I don't hear any Mexican stations.

Our biggest AM problem is Cuba, but Cuba probably doesn't have the money finance a switch to FM.

 

[davideduardo]

When is the AM disappearance set to happen? I am curious to see how different the AM band will sound, even in the Midwest, when this happens. I can't imagine how different DX will be in Texas and anywhere else in the South.

It's happening now, and in stages. Mexico divided the country into a number of regions, and did the administrative work in steps. The first one was the southeastern states of Yucatán, Campeche, Quintana Roo and Tabasco. All but about 12 AMs in those 4 states have migrated to FM, and the AMs will have to close down shortly. The other regions are on about 3 to 4 month intervals, but all end with about 650 of the 800 AM stations gone for good, with no reuse of those AM channels.

There will still be some AMs left, with most being in Mexico City, Guadalajara and Monterrey and along the US border where the FM band or international agreements don´t accommodate the wholesale move of AMs to the FM band. The other remaining AMs include a handful that provide indigenous language programming (Mexico has about 120 indigenous languages and dialects) to rural areas where AM is still efficient in reaching listeners.

A good resource is Fred Cantú's site http://www.mexicoradiotv.com/ where, if you see a station in an AM FM simulcast, you pretty much know that the AM will be gone shortly.

 

[davideduardo]

I can't imagine it will be much different for us Ohioans. These days, I don't hear any Mexican stations.

Our biggest AM problem is Cuba, but Cuba probably doesn't have the money finance a switch to FM.

Cuba just spent tens of millions having the Chinese rebuild most of the nation's AM stations. Cuba wants the AM dial densely populated to prevent outside signals from penetrating, a fear they do not have with FM.

 

[Same Thing Different Band]

The US seems to be doing the same thing on the FM Band, crowding translators, new US and Canadian stations in border areas, and increased IBOC interference without consumers buying radios to receive them, etc. into the existing FM band. I can't help but believe that the owners of large market Class B and Class C stations are celebrating the fact that you cannot receive those pesky out of market stations with innovative programming drawing 0.1, 0.2, and 0.3 Nielsen Arbitron shares and taking those precious fractions from the strong locals. The translators, border stations, and IBOC are making it hard to hear them or each other, since you can crowd several cochannel facilities into the same market area.

 

[MarioMania]

So when a station on AM in Mexico goes, No one can get it

 

[davideduardo]

So when a station on AM in Mexico goes, No one can get it

Correct. The Congress of the United Mexican States declared that, as the AM band was no longer economically viable, to save jobs and investments, as many stations as technically possible would be moved to FM. From that point on, the vacated AM assignments would not be reassigned. There is apparently an exception whereby the only possible new AM stations would be those serving indigenous or isolated communities where a showing that AM would be efficient was made. There also appears to be a provision for the remaining AMs to improve facilities as long as they meet all technical requirements.

 

[1L6E6VHF]

Correct. The Congress of the United Mexican States declared that, as the AM band was no longer economically viable, to save jobs and investments, as many stations as technically possible would be moved to FM. From that point on, the vacated AM assignments would not be reassigned. There is apparently an exception whereby the only possible new AM stations would be those serving indigenous or isolated communities where a showing that AM would be efficient was made. There also appears to be a provision for the remaining AMs to improve facilities as long as they meet all technical requirements.

I wonder if the government will allow the remaining major city stations to reuse some of the better bandwidth being cleared by FM conversion. For example, could we see some DF station moving to 540 and going high power since XEWA (San Luis Potosí) will no longer be there?

 

[davideduardo]

I wonder if the government will allow the remaining major city stations to reuse some of the better bandwidth being cleared by FM conversion. For example, could we see some DF station moving to 540 and going high power since XEWA (San Luis Potosí) will no longer be there?

I can't read anything in the legislation that allows capturing abandoned frequencies. But the Federal Commission has internal regulations that I have not been able to find (not that I really tried that much). The Mexico City market has a 540 on it already, XEWF, which could possibly apply to assume the clear channel operation of the SLP station. Since Mexico allows second adjacents in the same market, this would not be a problem to XEOC on 560 even at higher power.