Vulcan Red Steer Mk II Indicator below, it's the orange bit. I seem to remember from de-briefs with Aussie Mirage crews, on Darwin exercises, it worked very well. The Red Steer would track the incoming fighter and, at the appropriate time, the X Band jammer, having locked to the AI frequency, would zap the fighter radar. 'Jeeeez, Whole bloody screen just went orange' was the result.
Proper pickie at Andy Leitch's excellent Vulcan web -
http://www.avrovulcan.org.uk/andy_leitch_vol6/aeo2.htm