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Any idea what band do they use to control air traffic at the airport? My V1 goes crazy on K whenever I'm near an airport traffic control tower. The road also has a speed sign nearby. So I'm wondering if it's from the tower or the speed sign gives strong radar signal.
Speed sign. Air traffic control should be low-frequency VHF type of communications, some wind-shear measurement systems are LIDAR and may or may not set off your detector.Quote:
Originally Posted by lordhawhaw
However, some of the radar equipment used on airports are extremely high-powered and might overload (set off) your detector no matter what band they're on...
Atlantic City sets off X band for me
Air band is 108 - 136MHz and transmissions are in AM modulation.FM modulation wouldn't work because the plane is going too fast and FM modulated transmission would not "hold".This is the reason why air traffic control transmissions are in AM.Speed has absolutely no effect on AM.Quote:
Originally Posted by jdong
I think that I read somewhere that Westinghouse and Siemens AirTraffic Radars operate on L,S and C-bands(that's from 1GHz to 6GHz) ,but I'm not 100% sure.
Ground based air search radars are usually in the 400 MHz (usually military) or 1GHz range. Some wind shear stuff is radar based as well, but I don't know what frequencies are used.
Around airports you can have the "ASR" type radar that operates between 2700 - 2900 MHz. Long range radar, not normally close to airports operates 1215 - 1400 MHz. At your bigger airports you have ASDE radar which operates 15.7 - 16.2 GHz and 24.45 - 24.65 GHz. You have microwave links that operate in sseveral bands, 1710 - 1850 MHz, 7125 - 8500 MHz, 21.20 - 23.60 GHz.
My detector goes of for X band at one spot adjacent to the airport, Atlantic City, but I don't know what it is for, maybe some kinda part 15 link. Airborne radar operates 5350 - 5470 MHz and 9300 - 9500 MHz.
Rich Dunklee
NR2D
AM is still used because it because once FM became affordable, AM radios had become too pervasive in aviation and would cost too much money, not to mention the confusion and chance of missed communications in the transition, to switch. There are some technical pros and cons to using FM for aviation, but the financial and safety implications are the main driving force.Quote:
Originally Posted by MetalFlame
FM VHF/UHF radios are regularly used in aircraft being used as spotters for firefighting, law enforcement, etc. You'd have to be travelling far, far faster than any aircraft could today before it would start having a real effect on FM communications. Really there's no technical reason why it couldn't be used with proper frequency spacing to minimize the effects of FM capture. I brought my scanner with me on a recent flight, and just listening to weather radio transmissions, I could receive two totally independent stations that were transmitting on the same frequency probably 100+ miles apart just by moving the antenna a few inches. That's really the biggest technical hurdle using FM to communicate in aircraft.