During tonight’s Bexar County ARES Training Net, Lothar briefly mentioned the garage door problems those of us living near the intersection of 151 and Potranco Road (San Antonio, TX) are having. As Lothar correctly stated, the issue is a conflict between a new radio communications tower put up at the NSA facility being built on Military Drive and garage door openers in the vicinity.
The NSA tower works on the LMR 390 Mhz frequency, which is shared with older garage door openers, including, as it turns out, my own. As NSA has stated in public, they believe they have the legal basis for operating on this frequency, and do not intend to stop operating on this frequency. So, for those of us with garage door openers operating at that frequency, it means that your remote may not open your garage door until you are very close to it. In my case, I actually had to park in my driveway, get out of my car, and activate the remote standing two feet from the garage door. A bit of an inconvenience.
The Genie GIRUD-1T Universal Dual Frequency Conversion Kit alleviates frequency issues from the recently implemented Land Mobile Radio (LMR) communications system. The LMR system is used by military bases across the U.S. and was implemented as part of the nation’s Homeland Security efforts.
Most newer garage door openers operate on the 315 Mhz frequency to avoid this conflict. So if you are having these issues and would like some resolution, you can do one of two things: 1.) Purchase a new garage door opener that operates at that frequency, or 2.) Install a converter which will allow your existing garage door opener to operate on the new frequency.
I installed a converter in my house, and it works great. Good as new. I can easily open my garage door from a block away, which is what I used to be able to do before the NSA tower went up.
Installation took about 30 minutes, 20 minutes of which was spent just figuring out things in my head. Which is to say that it really is a simple fix. I ordered the conversion kit from Genie directly, though I did see some in the garage door section of the Lowes at Alamo Ranch out at 1604. I imagine other hardware stores might also have it in stock.
Keep in mind that if you do buy the kit, it only comes with one new garage door opener. So unless you can reprogram one of your other ones to operate at 315 Mhz, then you’ll have to buy a second (if you need two for two cars). I bought a second one for my car also at Lowes.
Here’s a link to the kit that I used: http://www.ezgaragedoor.com/ezgarage001sc/product_3580.html
I paid about $50 myself ordering from Genie. Installation was quick and easy. If anyone needs to install this conversion kit and would like some assistance, please feel free to let me know. I am not very mechanically inclined, but I know I can install the conversion kit! Also be happy to show the install to anyone who might want to come by the house.
Please feel free to shoot me an email if you have any questions at wmartyn@gmail.com.
Wade Martyn, WB5C
July 11th, 2018 at 8:30 PM
It sounds like the NSA has learned how to extract CPU state and memory using radio frequencies. The theory is kind of basic.
In short:
* Bombard a datacenter outside wall with 300mhz waves.
* The waves hit a server, and when the metal resonates it emits base + harmonic frequencies.
* Harmonics for 300 MHz are at 600, 900, 1200, 1500 etc.
* CPU radio noise causes intermodulation which changes the harmonic frequencies by a sum amount.
* Detect multiple servers because each metal object resonates at a different time domain phase, allowing you to isolate CPU’s separately.
* Capture harmonics wireless nearby at 300-2400 MHz
* Weak harmonics higher then 2700 MHz captured from flat surfaces like walls or maybe power-lines.
* You subtract actual harmonic from the expected harmonic, and get the actual CPU frequency noise.
University students already know how to use CPU noise to read CPU state registers very close to a computer. The NSA just needed students and radio engineers to make long-distance memory theft possible.