Mexican interference?

[K6GBW]

I recently found out Mexico did some re-allocation in the 440-450 MHz area, and it’s mostly business radio now. I don’t know if this is for simplex or repeaters but I’m wondering if anyone has experienced interference with the American amateur bands since this occurred. I’m in Los Angeles so I’m a bit far from the border, but it’s not outside the realm of possibility that we’ll get some interference from high level repeaters up here.

 

[ecps92]

I recently found out Mexico did some re-allocation in the 440-450 MHz area, and it’s mostly business radio now. I don’t know if this is for simplex or repeaters but I’m wondering if anyone has experienced interference with the American amateur bands since this occurred. I’m in Los Angeles so I’m a bit far from the border, but it’s not outside the realm of possibility that we’ll get some interference from high level repeaters up here.

Please provide the citation for this, as the only sources found with Mexico RF changes, do not mention 440-450

ie:

Mexico: Federal Telecommunications Institute Modifies 2025 Frequency Band Program

Mexico’s IFT has modified the 2025 Frequency Band Program, reallocating spectrum for public and private use while preparing for regulatory changes under the latest reform.

globalvalidity.com

 

[K6GBW]

I'm a member of LA County DCS and spend my Wednesday mornings at SCC doing the SHARES and Cal-OES nets. My mentor there told me about it yesterday. This guy has forgotten more about radio than I'll ever know. He's connected to everyone in the industry and finds out things pretty much when they happen. He told me that Mexico just recently made a decision to reallocate the 440-450 MHz area to businesses (apparently it's never been open to amateurs there).

We also found out about a private company based on the Los Angeles area that has a license for radar testing in the 220 band. So things are getting strange. Mexico has demonstrated that they don't really care what we're doing up here, they do what they want regardless. They put up a TV transmitter right on the 700 MHz frequencies that LASD was going to use on their new LARICS system, and that effected it's deployment in a really negative way.

I imagine as time goes on Mexico will publish something more definitive, but for now that's what I have.

 

[wd9ewk]

Please provide the citation for this, as the only sources found with Mexico RF changes, do not mention 440-450

That article talks about changes to those allocations. It may not have addressed allocations that have been in place for a long time.

The most recent National Frequency Allocation Table ("Cuadro Nacional de Atribución de Frecuencias", or "CNAF") I could find, from late last year, shows 440-450 MHz allocated to mobile (excluding aeronautical mobile - "móvil, salvo móvil aeronáutico") and radiolocation ("radiolocalización") services. The Mexican allocations are in the "MÉXICO MHz" column below:




This is, more or less, the same as it was in 1999. In 1999, 440-450 MHz was allocated to fixed ("fijo") and land mobile ("móvil terrestre") services. Again, the "MÉXICO MHz" column below shows this allocation:




Sometime before 1999, Mexico took the 440-450 MHz range away from radio amateurs, leaving amateurs with just the 430-440 MHz range. Even with this, I remember hearing some amateur repeaters operating (illegally, apparently) from Mexico in the 440-450 MHz range in the early 2000s, when I could get amateur permits from the SCT office in Mexicali.

 

[K6GBW]

Hmm...well then maybe we won't get any new interference, so that's good news. Lately we've been getting a rogue digital signal on our P25 repeater. I haven't been able to determine the type of signal yet. I know it's not P25 so I'm listening to DMR and D-Star, though I can't imagine anyone putting up a D-Star machine around here. The LA area, unfortunately is so RF crowded that people put up uncoordinated repeaters all the time. It can be a real chore to track them down.

 

[AM909]

Just like the 47 CFR freq tables, those tables (based on the ITU tables) have a lot of pertinent info in the notes.

Is anyone else seeing unusually high interference in the 455-460 range today (09/11)?

 

[d119]

Interference in the upper part of the 440 band from Mexico has been an ongoing problem for years. I suggest reaching out to SCRRBA to express your concerns.

They are running higher-power DMR systems with full time encryption on them, so you likely won't be able to decode any traffic, it's been tried extensively to attempt to positively identify who it is.

People back in San Diego are really feeling it.