Dr Bernard Lovell, a charismatic character, was given direct
instructions to concentrate his research efforts, not on AI
directly but on a derivative for bomb-aiming. The work proved
complex and the development of serviceable equipment was difficult.
Churchill ordered a special Halifax bomber to be built that
had a downward facing Perspex dome fitted. This aeroplane
(V 9977) arrived at Hurn in late March 1942 just as TRE was
ordered to transfer to Malvern.
The air trials began in April but on June 7th, the plane crashed
in S. Wales, all on board perished including a number of the
leading scientists who were working on the project. Another
setback had been the insistence that a Klystron valve be used
in the equipment rather than the far superior (but unknown
to the Germans) Magnetron. The Klystron did not work well,
not enough power could be generated, and so by August 1942
it was decided (with Lovell's persuasion) to redesign the
equipment using the new Magnetron. The transmitters worked
on a 9 cms wavelength.
Churchill (at Lovell's persuasion) ordered two squadrons to
be equipped by the autumn and by Christmas, 50 sets had been
January 30th 1943:
The first operational use of H2S ("Home Sweet Home")
fitted to a 'Pathfinder' Squadron took place in a large raid
over Hamburg. The weather was poor but the results were deemed
successful. So now the allied bombers could be flown accurately
to their targets using GEE and drop their bombs using H2S
and there was no need to radio back to ground control and
so any theatre of operations could benefit.