Have Quick
Have Quick (also HAVEQUICK, short HQ) was an ECM-resistant frequency-hopping system used to protect military aeronautical mobile (OR) radio traffic. Since the end of World War II, U.S. and Allied military aircraft have used AM radios in the NATO harmonised 225–400 MHz UHF band (part of NATO B band) for short range air-to-air and ground-to-air communications.