One duty which gave me and my colleagues the greatest satisfaction and encouragement, were visits to the Services' research and administrative establishments at Heslemere, the Royal Aircraft Establishment at Farnborough and the Telecommunications Research Establishment on the premises of the Malvern School. The mixture of permanent scientific civil servants, serving officers and technicians and the top scientific brains from the Universities provided most stimulating company. Even the formal conferences were full of interest, putting us in direct touch with Operational Arms of the Services who had used or expected to use our equipment.
As often as not, we stayed over in one or other of the messes attached to these establishments, and found these occasions a much needed intellectual stimulus. At dinner, lunch or breakfast, freed from the presence of the Admiral or Vice Marshal who had chaired meetings, we had a chance to hear the real inside story of many of the services' activities and exploits. I remember one breakfast at Malvern, when a young fellow joined us observing as he sat down, that the weather at Peenemünde (the German Rocket station on the Baltic) had been quite good!
Another occasion was a verbatim recital of his experience by one of the civilian scientists who had gone over Germany the night before, on a bombing raid to test the new tail gunners warning Radar. Many aviation electronic experts were lost in such tests over enemy territory or at home. One of HMV's chief scientists, Mr. Brown was killed with his complete design team in a crash when on an experimental flight in Worcestershire, and Air Commodore de Burgh of the R.A.E. who with his wife had stayed with us at Malmesbury was lost over the Atlantic on his way to a meeting in Washington.
One of the most successful Radars towards the end of the war was the famous H2S. This was also a derivative of the 10 cm technique as used for the AI Mk VIII. The accuracy of our bombing up to 1942/43, contrary to what had been claimed in the communiqués was appalling, and bombs were dropping miles from their targets, or on many factories and airfields made of canvas and plywood.
The use of this 10 cm wavelength as against the earlier 1.5 metres was quite revolutionary in this field of application. It was the difference in definition of reflected signals between, say, a painting done with a 1" paint brush as against an etching. In the case of H2S the aerial pointed downwards, so that all the different features on the ground, such as rivers, railway lines and factory buildings stood out in various degrees according to the degree of reflection of the Radar Pulses. Our bombing accuracy improved tremendously and Bomber Command recovered some of the reputation it had lost in official circles arising from earlier failures.
Our contribution to H2S was only the power pack and modulator, but I never learned the origin of the code name. Most Radars apart from AI and ASV, were known by girls names such as Sarah, Rebecca, Monica etc. Probably like the chemical of which H2S is the formula, it stank in the German nostrils. On one visit to TRE I saw a photograph of the H2S screen, of the famous railway marshalling yards at Hamm and another of Essen, which lies in a valley and had hitherto been very hard to bomb with any degree of accuracy. The railway lines and factory buildings were as clearly defined as in a flash photograph.
The last equipment we were to produce was the ancestor of the present generation of target seeking bombs and rockets, and was designated AI Mark IX. Whereas the Mark VIII enabled the night fighter to pick up and approach an enemy bomber from a considerable distance with great accuracy and could approach from any angle to the rear, the fighter had to be guided by the pilot to within firing range.
The Mark IX was intended to locate the target as with Mark VIII, the receiver then being "locked" on the signal in such a way, that by means of a servo-coupling to the plane's gyroscope, the fighter maintained by automatic control of direction and elevation, a constant attitude in relation to the target while it closed in and when the target came within firing range, the guns would automatically open fire, whatever evasive action was taken by the target, the attacking fighter would automatically follow like a whippet chasing a hare.
This gear was conceived and basically designed at Malvern by largely the same team as Mark VIII under Professor Dee, although by then - 1944 - Dr. Bircham had gone to the USA to work on the atomic bomb although we did not know at the time. The same procedure was used as for Mark VIII for the pre-production collaboration between TRE, the Malmesbury development section under Tony Martin and the Cowbridge factory.
At our first meeting at Malvern, the "breadboard" Mark IX was connected to an aerial mounted on a simulated plane with its gyro controls and a telescope coupled up to the set instead of guns. It was a cloudy day with the occasional clearings and the oscillating aerial was switched on. When what seemed a suitable signal was received on the screen from the target bomber which was flying in cloud the "lock follow" unit was switched on.
The mounted telescope followed the invisible target plane and by keeping an eye to the eye piece, when the plane came out from behind the cloud it could be clearly seen through the telescope, which automatically kept itself sighted on the target. This all seemed very wonderful at the time, and it was the system already in use for controlling multi-barrelled quick firing guns in the Navy.
The war finished before the final design of Mark IX was completed, but I believe it did go into restricted production for a time after the war when I was no longer involved. This , it must be realised was before the discovery of the transistor and solid state circuits; a Radar for airborne use could contain over 100 valves in its total Radio and Radar equipment, and these valves were always the weakest link in the circuits.
I sometimes reflect that when I was a student in 1920, the only electronic valves known were elementary triodes which were not much more than electric light bulbs modified with the addition of a grid and anode, and within 20 years, the art had developed so far as the cavity magnetron.
In the 30 years since the war, electronic science and technique have so developed that dozens of micro circuits can be accommodated on a single segment not much bigger than a pinhead. The whole technique of electronic production has been revolutionised, that having ceased my association with the electronics industry in 1946, it is now as foreign to me as if I had never been involved in it.
