As all UK companies were involved in many activities in which they were linked in various ways it is helpful to have a general review of the situation, so John Brown has compiled an introduction:

 

THE CONTRIBUTION MADE BY THE BRITISH RADIO INDUSTRY DURING THE LEAD-UP TO, AND THROUGHOUT, THE SECOND WORLD WAR

 

METROPOLITAN-VICKERS (METROVIK) LTD - Trafford Park, Manchester.

1932-1935 - Physicist Dr J M Dodds and Engineer Mr J Ludlow, who jointly ran the Valve Laboratory, were involved over this period with the GPO Transmission Group at Daventry, who were evaluating Metrovik’s new continuous evacuated, demountable, water-cooled transmitter valves. In 1933 - early on in their work - a GPO engineer noted that when an aircraft flew past their transmitting centre, it affected the radio reception; however, their work at that time was only to evaluate transmissions in the short wave band (3-30 Mc/s).

 

Back in London, the dominant concern was the perceived German bomber threat, which led to the setting-up of the Committee for the Scientific Survey of Air Defence in November 1934 by Sir Henry Tizard. Shortly after, Robert Watson Watt issued his Memorandum which postulated a solution; it was quickly followed up in February 1935, with the demonstration at Weedon in Northamptonshire. It proved that the fundamental idea was sound; this resulted in the release of Treasury funds for the establishment of the Air Ministry Experimental Station (AMES) on Orfordness in May 1935. Initial progress there was rapid and a prototype Pulse Transmitter was ready two months later.

 

It was foreseen that a larger site would be required, and after a search, Bawdsey Manor was acquired; the move took place during February and March 1935; it became the new AMES. In 1939, the decision was taken that the scientific team should move to Dundee; as a result, the Manor site became RAF Bawdsey - a Station now in its own right.

 

INITIAL ORDERS FOR RDF

May 1936 - Metrovik received an order for 4 Transmitters and 2 Control Desks. May 1936 - A C Cossor received an order for 2 Receiver/Display equipments. Cossor built these equipments based on a design by the Telecommunications Research Establishment (TRE).

February 1937 - Ministry of Aircraft Production set up a network organisation to cover the whole of the RDF project, its implementation, and co-ordination.

 

Apart from Metrovik and Cossor, other companies participating included the following: Dorman-Long - steel suppliers; J. L. Eve Construction Ltd - fabrication of Towers and Masts at each RDF site; and the Radio Transmission Equipment Company - supply of Goniometers. The design of the antenna was a joint project between the AMES and the GPO Group, with Marconi Wireless Telegraph Company Ltd responsible for the provision and erection of the ‘curtain’ antenna arrays.

 

April 1937 - Metrovik - Order placed for 16 Transmitters & 8 Control Desks.

June 1937 - Shipped to Bawdsey, the first 2 Transmitters & 1 Control Desk.

July 1937 - Shipped to Bawdsey, the second 2 Transmitters & 1 Control Desk.

October 1937 - Shipped to Great Bromley Essex, 4 Transmitters & 2 Control Desks.

January 1938 - Shipped to Dunkirk Kent, 4 Transmitters & 2 Control Desks.

February 1938 - A bulk order for 88 Transmitters & 44 Control Desks.

April 1938 - Shipped to Swingate/Dover and Canewdon Essex, antenna, supporting masts and aerial feeder cables.

August 1938 - First 5 RDF Stations - Bawdsey, Great Bromley, Canewdon, Dunkirk, and Swingate/Dover became operational and entered service during the Munich crisis; in full-time operation from September1938.

November 1938 - Metrovik received Transmitter orders for 30 CH (L), and for the Army - 30 Coastal Defence (Mobile Units).

December 1939 - Metrovik received its first orders for 10 Airborne IFF sets.

January 1940 - Further orders for 80 CH (L) and 60 Coastal Defence (Mobile’s)

March 1940 - Metrovik delivered modifications to all the CH stations to change from continuous-wave class B type transmission, to pulse-modulated class C type transmission. Aircraft detection range now increased to at least 150 miles.

October 1940 - Royal Navy approach Metrovik for radio location equipment for ships; ultimately, this led to the Type 271 and Type 272.

 

EKCO (E K COLE LTD) - Southend-on Sea.

The earliest days of radar work - as far as Ekco was concerned - started in March 1938, when TRE (Telecommunications Research Establishment) approached the Technical Director (Mr A W Martin), via Mr E K Cole, to carry out experiments on Radio Location. Ekco had a long-established reputation for innovation, and the quality of its products. This new undertaking was to progress the work that Eddie ‘Taffy’ Bowen had pioneered at Bawdsey.

 

The commission would cover research and development, and thence on to full production of AI (Airborne Interception) radar for the night-fighter force, and ASV (Anti-Surface Vessel) radar for Coastal Command and the Fleet Air Arm. The task had the highest priority.

 

The initial laboratory utilised the entire top floor of the ‘Casino’ building on Canvey Island, made available for the sole use of Ekco, operating under the strictest secrecy conditions; the location was ideal, facing on to passing shipping in the Thames Estuary.

Mid-1939 and onwards - Bletchley Park’s Monitoring Service acquired a number of Ekco Embassy 10 advanced design short-wave receivers (whose performance had been further up-graded) as the first monitors of the German Enigma transmissions. Mr E K Cole in person - not the Ekco Company (for security reasons) - was the point of contact for Commander Ellingworth, the Head of the Monitoring Service.

 

August 1939 - with war imminent, an RAF deputation led by Group Captain Hugh Leedham, Director of Communications Development, called an 08.00 Saturday meeting at Ekco’s Head Office, with Mr Cole and his senior executives. The crucially important development and production of AI and ASV must be carried out at a top secret location; however, it had to be within a 100 miles radius to the west of London.

 

Michael Lipman, Ekco’s specialist in factory planning, was tasked with the conduct of the search - and whilst not being specified - it was implied that the equipment to be produced would be of dimensions not greater than television sets. He was instructed that on approval of the premises of his choosing, they were to be equipped with sufficient machines and tools to enable him to organise production of this unspecified equipment, utilising not more than 200 people. In the event of war, he could recruit a nucleus of staff of not higher than foreman level from the Main Works at Southend. He was to depart on his search mission immediately.

After an extensive and comprehensive search, he chose a country house within two miles of Malmesbury in Wiltshire. This was Cowbridge House, an 18^th century house set in 14 acres, close to the banks of the River Avon, which meant that industrial water was available, as was electrical power from its own water-powered generator. The Estate came complete with numerous outbuildings and cottages. He knew straight away that this was the place. The house and the whole Estate were promptly purchased for £6,500 cash. By Christmas 1939, conversation work was completed, while at the same time, making sure that the property retained its appearance of being a country house. When it was operational, packing cases piled outside buildings had to be kept hidden under camouflage netting, and reconnaissance aircraft flew over regularly to check that there were no tell-tale signs of activity.

In June 1940, the ‘Top Secret’ research and development laboratory, together with its own workshop, was transferred from Southend to Malmesbury High Street. Here, vacant shops were acquired - and behind painted-out shop windows, conversion work took place to create laboratories and the workshop. This became the WDU (Western Development Unit). These laboratories worked under a cover story of being Ministry of Agriculture and Fisheries offices; thereby - for security reasons - it was kept completely separate and unrelated to Cowbridge House.

 

The WDU Research and Development staff worked ceaselessly with TRE (whose staff included - by this time - the scientist Bernard Lovell), refining the design and performance of AI radar. In July 1940, this resulted in the world’s first successful radar-assisted shoot-down of an enemy aircraft.

 

In parallel with the development and manufacture of night-fighter radars, Ekco also developed and produced ASV radar sets for Coastal Command and the Fleet Air Arm, where they were instrumental in defeating the U-boat threat. With the invention of the cavity magnetron in 1940, a quantum leap forward in performance was made possible, and night-fighters such as the Bristol Beaufighter and the De Havilland Mosquito were soon to rid Britain’s night sky of German bombers.

1941 - AI Mark 4 and ASV Mark 2 radars were in production.

1942 - ‘Centrimetric’ AI Mark 7 and AI Mark 8 radars in production.

1943 - ‘Centrimetric’ ASV Mark 4 in production.

During the war, over 8,500 AI radar sets were manufactured, along with 3,000 ASV radar sets, with production being shared with Pye Radio of Cambridge.

 

Production of H2S equipment was also carried out at Malmesbury.

After the war, production continued at Malmesbury making AI radar sets for fighter aircraft such as the Hawker Hunter; they also made ASV radars for the Fleet Air Arm Fairey Gannets. With the threat posed by the Cold War, in the late 1950’s, EKCO made the tail-warning radar for the RAF’s V-Bomber fleet.

 

Footnote: Sir Bernard Lovell’s long association with Ekco Malmesbury is remembered by a road named after him, close to the ‘Cowbridge House’ site which he opened personally at a civic ceremony in November 2009; also invited were some former Ekco employees who had worked there during the Second World War. On the same Estate is another road -‘Lipman Way’ - named as a tribute to Michael Lipman, the Ekco manager who first found and purchased ‘Cowbridge House’ in the dark days of 1939. He was responsible for its conversion to the ‘Top Secret’ factory it became, and managed it throughout the War. His wife ran the Hostels, as well as supervising welfare and the social aspects of the enterprise; a truly remarkable couple.

 

EKCO WORKS - Southend-on Sea.

September 1939 – Production began of the WS18 mobile HF/VHF/ intercom radio transceiver for inter-tank use by the British Army. This equipment had been designed by Pye Radio, and because of the quantities required, it was also manufactured by Bush Radio and Murphy Radio.

 

May 1940 - At the time of the Dunkirk evacuation, the threat of invasion seemed imminent, and the order was given by the Ministry of Aircraft Production to disperse manufacture away from Southend, which was considered to be in the front line. The Ministry of Aircraft Production had provided a list of potential locations and sites; Ekco chose Aylesbury for its main factory, and nearby Aston Clinton for the Head Office. Aston Clinton House - a former Rothschild property - had been altered some years before to create the ‘Green Park Hotel; it was now taken over as its Administration Centre. Some of the bedrooms were set aside for visiting managers; the remainder for staff use. The former Stable Block was altered to provide development laboratories and a model shop; the conversion work was carried out by Ekco’s Maintenance Department.

 

The colossal task of moving an entire major factory and the Head Office was accomplished in one gigantic effort. During Whitsun 1940, the Ministry diverted a vast fleet of lorries to Southend, and for hours the police closed the A40 to Aylesbury, the London North Circular road, and all four lanes of the Southend Arterial road.

 

The huge ‘Bakelite’ moulding presses - impractical to move - remained at Southend and utilised for munitions work, as did the Lamp Department which reverted to valve manufacture again - but now for radio-location applications. Three further shadow factories were located at Woking for WS19 ‘tank radio’ production; at Preston for lamp production; and at Rutherglen, Lanarkshire, for the manufacture of radio components and transformers.

June 1940 - Aylesbury had been contracted to manufacture the T-1154 and R-1155 transmitter/receiver sets. Resulting from numerous technical meetings, the design and development engineers at Aston Clinton carried out re-engineering work on both units for airborne use, before putting them into production. These sets were an original Marconi design that had a steel chassis, whereas the Ekco airborne version had an aluminium chassis for weight-saving reasons, as well as other modifications, either suggested by Ekco or required by the RAF.

 

1941- Production started of the T-1154 and R-1155 transmitter and receiver sets, which became the standard set for Bomber Command for the duration of the war. This equipment was additionally manufactured by EMI (Hayes), Marconi (Chelmsford), and Plessey (Ilford).

 

1942 - The Woking shadow factory developed and manufactured the WS No.46 portable man-pack radio for the commandos.

 

!943- Production returned to the main factory in Southend-on-Sea, with the vast assembly hall now manufacturing Type 19 wireless sets and ‘wiring looms’ for bombers - principally the Avro Lancaster.

Towards the end of the war, with pre-war wirelesses wearing out and more households becoming out of touch as a result, the Southend factory was allowed to first finish off the sets abandoned part-made in 1940, and then to make a cheap unbranded utility set.

 

PYE RADIO - Cambridge

One of the most significant contributions to the war effort can be traced back to early 1939, when Pye engineers were designing their Model 915 television set for the forthcoming ‘RadioOlympia’ exhibition. The set was designed for operation in ‘fringe areas’ (at the limits of coverage from Alexandra Palace - then the sole BBC Television Station). Pye needed an RF amplifier valve with excellent high frequency properties. Through the Mullard Valve Company (Philips’ UK subsidiary), contact was made with the Philips Research Laboratories in the Netherlands, who it was known were developing the EE50 glass-base valve. Pye proposed some modifications to its design, in order to meet its own special requirements. After the initial samples were received, Pye design engineers made some alterations to the valves’ base to improve its performance, and also because of some noticeable distortion effects - resulting from poor screening of the valves’ inner surface -they devised a small red spun-metal jacket to remove them. The Mullard Valve Company manufactured the new red EF50 for Pye. The Model 915 television was displayed at the 1939 ‘RadioOlympia’ exhibition - incorporating their new TRF receiver using five EF50’s - later to become well-known as the ‘Pye Strip’; it was used widely in military radar equipment - both ground and airborne in the Second World War.

 

1940 - Pye stressed to the Government that, although they had a stock of EF50 valves in their Newmarket warehouse provisioned for their pre-war television needs, these would be used up rapidly by the forthcoming demands of radar. By the March, the Government recognised the emergency, and invited Dr Th. P Tromp, General Manager of Philips Electronic Valves to London, where at a secret meeting Watson Watt asked him to send to Britain all the EF50 valves they had, and the tools to make them. Tromp loaded up a Dutch Merchantman (which evaded a German air attack) and arrived at Harwich on 9 May with 25,000 valves and 250,000 valve bases. Hours later, the German army invaded the Netherlands.

 

1939 - WS No.18 the Pye-designed man-pack HF/VHF radio for the British Infantry was manufactured in large quantities.

1940 -The development of the CD and CH (L) radars placed a heavy workload on the Cambridge factory; soon the order for CHL stations rose to 40, of which 25 were to be mobile. Pye undertook to provide the receiver rack and cathode ray tubes, with the ‘Pye Strip’ fitted into a receiver designed by TRE. The mobile CHL was mounted on two trucks for which Pye made the antennae out of chicken wire, and also designed the turntables and steering gear.

Summer 1940 - The Ministry of Supply placed orders - on the Army’s behalf - for another 120 CH (L) stations; part of this order was carried out by Invicta, a subsidiary of Pye.

1941 - WS No.19 set. Designed and manufactured by Pye; it was also manufactured by Bush Radio, Ekco, and Murphy, and abroad in North America and Canada.

1942- WS No.22 set. Designed and manufactured by Pye.

!943 - Radio Link Sounding Range Mark 2, and Communications Rx. Type PTR.

1944 - Communications receiver Type PCR, and WS 10 microwave radio relay station (transportable mounted on a wheeled trailer).