In November 1942 the Allies used a jamming system that blocked the German service's ground-to-air communications systems.
A microphone that amplified the noise of one of the engines of a bombing squadron aircraft was used to confuse the German communications systems. When the operator listened to the frequencies and realized the communication, he transmitted on the same frequency the amplified noise of the engine, thus managing to block the interference in a disguised way.
A curious jamming system was not an electronic device but a radar signal reflector that was used as a decoy. Many pieces of aluminum of a certain size were thrown into the air to reflect the German radar signals interfering with how they worked. It was believed thanks to these signals that it was a large fleet of bombers going to a certain place. While they were hunting for these so-called bombers, the real planes were going to counter the enemy movement. With well timed courses in this trap, the enemy became unable to adequately combat this tactic as they ran out of fuel and were attacked by surprise from the rear.
In August 1944, the Allies put into operation a jamming system that combined a wide range of frequencies simultaneously. This system was installed in place of an aircraft's ventral turret.