BBC Radio 4 interview with Doug Robb, Manager, RAF Air Warfare Radar Museum, RAF Neatishead, Norfolk, April 2002
DR: Doug Robb; GN: Gerry Northam
GN: Say who you are...
DR: Doug Robb, manager of the RAF Air Warfare Radar Museum.
GN: I understand you were formerly a radar operator...
DR: I was a radar operator from 1960 until the end of 1997.
GN: Whats your title and role here?
DR: Im Museum Manager which is an all encompassing term for the only employee and general dogsbody.
GN: How long has there been an RAF radar station here?
DR: The first radar system came here in 1941 and its been running continuously from this site ever since....
GN: This is a system from the 1950s ... just explain what Im looking at.
DR: What were seeing here is a standard radar tube showing the picture from a Type 7 radar, with a range of about 90 miles. As the trace goes round you can see out to the east, the banana shaped radar responses indicating the aircrafts position.
GN: As that orange trace sweeps round I see the Norfolk coast at the top...
DR: Yes, round to the Thames Estuary and Kent at the bottom and out across the sea, the positions of aircraft indicated by the radar...
GN: And those two little banana shaped things are...?
DR: Aircraft positions as you see on the overlaid map.
GN: And next to it this other machine shows what?
DR: Well that shows what is crucial in radar, the third dimension. The height of the aircraft. So with a slightly different display we can see the aircraft presented as a spike on that screen and the operator can read the height of that spike, convert it to thousands of feet, so that we know the height of the aircraft.
GN: So in the early 1950s this was the state of the art?
DR: Yes, thats correct. Until about generally speaking 1954 into 1955 when longer-range, more accurate radars came along.
GN: What would a controller do, sitting in this chair?
DR: Well he would sit there, assess the situation on his screen and the first thing he would need to do is identify is which of those blips is his fighter and which is his target. And then he would simply talk to the pilot of his fighter and give him directions to steer towards that target, until he got close enough to see it and then carry out whatever action was required.
GN: And this bakelite microphone here, was that used for constant contact?
DR: Constant contact talking to the pilot through that what we called the Black Tulip microphone, and hearing the pilots response on the speaker on top of the console.
GN: And this would be a constant dialogue between them?
DR: It would, full of the standard R/T jargon of the day, over out, roger, phrases like that.
DR: Judy was a simple one for the pilot to say Ive seen the target, Im close enough and Im about to shoot it down.
GN: Now what could happen in those early models to make the radar controller see something that was a genuine image on the screen but which didnt reflect a genuine something that was out over the sea?
DR: There would be many reasons. There would be atmospherics, there would be a temperature inversion which would cause the radar beam to bend and indicate targets in a false position.
GN: How would that happen?
DR: Radio waves travel in straight lines but they can be affected by a temperature gradient in the atmosphere...the beam will bend and tend to hug the surface of the earth, so you would get longer range at lower level but it would indicate false things to the man observing at the time.
GN: What else might give a phantom image?
DR: Internal interference from the transmitter, from the receiver, external interference from a local source, be it an engine nearby. There are many reasons why a radar picture as presented may not have actually reflected what was happening out there in the real world.
GN: An occasion as described by Freddy Wimbledon when there was an image on the ground radar, and on the radar in a plane, but when the pilot looked there was nothing there, would be explained by what?
DR: I havent a clue on that one. I think perhaps something like as has been mentioned before, ball lightning, can give a reflection but of course it has gone in an instant. But of course thats only my own opinion. There are a number of things that I certainly couldnt attempt to explain on this subject.
GN: Was it common in the 1950s for radar controllers to see things which werent there, though they were seeing them on their screen?
DR: I wouldnt say it was common. Much of the objects seen travelling at high speed on radar screens have been revealed after investigation to be the re-entry of pieces of debris from space be it comet or man made.
GN: So theres something there but its not what they think it is.
DR: Yes, thats right.
GN: In the 50s, Freddy sat in a chair like that, what was his job to look for?
DR: Well his job as has been done since 1938 in this country was to track everything that flies in his area of responsibility and identify it. And if it is not identified take the relevant action, bearing in mind at the time we were looking at surprise attack from the Soviet block nations.
GN: And here you are on the east coast, looking east, you are going to see it first.
DR: Yes, thats correct. Although having said that as part of NATO we were getting information from the Continent which was obviously nearer the threat.
GN: If a radar controller saw something coming in, what would they do if they could not identify it?
DR: Well once they had confirmed, within two minutes, that they didnt know the identity of that track then they would simply have to scramble fighters to go and have a look...its the only way...
GN: So they would only have two minutes?
DR: Two minutes. As it has been and still is.
GN: Why two minutes?
DR: Its time enough to assess all the information available, and there are lots of agencies who can help, but not too long so that you dont take any action at all, in a timely fashion. Two minutes in the laid down procedure.
GN: And if in two minutes the radar operator hasnt worked out what it is, then scramble the planes?
GN: And this has happened?
DR: Constantly, during the Cold War.
GN: Would it have been Freddys decision to shoot down?
DR: No, definitely not.
GN: Then it was the pilots decision?
DR: No...that would be take at a much higher level....
Transcript copyright David Clarke/BBC Radio 4 Manchester 2002