Originally Posted by
jmelson
The Germans had the X Gerate (Don't know how to type the umlaut) which was a single beam, and the Y Gerate which had 2 beams that intersected to mark the target. These beams were VERY narrow, only a couple hundred meters wide in England (projected from sites in France). So, you really needed a plane to catch the beam, as they were redirected every night for a different target. The Germans initially set up the beam in the early afternoon, to make sure the equipment was working and properly aimed. If the British could detect the beam as soon as it was set up, they had a number of hours to mobilize equipment and manpower to defend against the attack.
Jon
Before X and Y Gerate you had Knickebein based on the Lorenz system which was produced pre war. The aircraft flew down a beam with morse dots to one side and dashes on tho other. In the middle was a steady tone 'equi-signal'. Approaching the target the observer tuned to the second sigal crossing their path when the obtained the steady tone, tey dropped their bombs. The system was actually difficult to jam as you needed to know both frequency used and how many cycles/second it was transmitted on. X and Y Gerate were far more automatic and incorporate timers therefore easier to spoof and jam.
I think Y Gerate had three cross beams, the first was a warning to the crew to prepare, second the observer started a clock which ran slowly and at the third a second clock was started which ran 3x faster than the second when both reached zero the bombs bropped automatically.
As with any beam reliant system the further from the transmitter the less accurate it is.
This was the start of electronic warfare as we know it today. We still use chaff which was originally called window and Dupel by the Luftwaffe, coincidently it was invented by both sides at the same time.