Grampian Parabolic Reflector.
This was an amazing piece of equipment. I remember pointing it out of a window at home and listening in to conversations at the end of the street! As far as railways were concerned it certainly gave great sensitivity and cut down on wind noise. The problem I became aware of was that the tonal balance of the recordings was quite dramatically altered. There was an 'adjustment' you could make to the DP4 microphone to help, but it still didn't make things right. Today I find the recordings I did with it can be considerably improved with the Aphex Aural Exciter.
These parabolic reflectors are still used today for recording bird songs. I gave mine away to a work colleague who used it for picking up early amateur radio transmissions from an 'Oscar' satellite.
