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1896 to
The history of the Pye Group of Companies in scientific & analytical instruments, radio & line communications, broadcasting, domestic radio & TV and industrial electronics from 1896 to the present day
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Pye Telecom
* The information on this page is adapted from an original manuscript by Mr. D. B. Delanoy, with the permission of the Author

Birth of Pye Telecom

C.O. Stanley was always alert to new opportunities, and as a result of the experience gained in the wartime design and production of military wireless and radar equipment, the management of Pye anticipated that a post-war market for civil radio communications would develop. They decided at an early stage to prepare for this opportunity.

On 3 February 1944 Pye Telecommunications Limited (PTL) was incorporated as a limited company for this purpose, created as a wholly owned subsidiary of Pye Limited.

When the war ended, and work on military equipment reduced, the existing research group of Pye Limited, (called Pye Research Labs), initially carried out the design and development activities on the future Pye Telecom products. Later, selected staff transferred from Pye Labs to the new telecommunications division.

Ditton Works  
Pye Telecom Headquarters, Ditton Works, 1948-1979

The first official Pye Telecom premises comprised a pre-fabricated corrugated steel building with about 100 square metres of floor space, located on the left of the sharp bend in St. Andrews Road, Cambridge, where later in the 1970s the entrance/reception area for the new "Site 1" complex would eventually be constructed. In 1948 Pye acquired from the Home Office a gas mask factory and store located at the top of Newmarket Road, adjacent to Ditton Lane. For the next 30 years, this was the home of Pye Telecom and known as Ditton Works.

The very first Pye Telecom product was not related to telecommunications, but it was still a transmitter of sorts. It was a high power RF induction heater using radio frequencies to speed the setting of adhesive in the construction of the De-Havilland Mosquito, an aeroplane, which was largely constructed of laminated wood.

The new company quickly settled down, with a small team led by Donald H. Hughes and William M. Pannell. They started work on a very ambitious plan to design a complete range of VHF mobile and base station transmitters and receivers to be available in the market place by early 1947. This goal was achieved, and in 1946 the equipment was publicised in Wireless World magazine and by early 1947 the PTC104 base station and the PTC102 mobile were in production. The first customers were the UK Home Office for the UK Police.

Between 1946 and 1949 many people who were later to become well-known figures in the UK radio industry joined PTL, including J.R. Brinkley, B.D. Armstrong, D.B. Delanoy and Richard Q. Marris etc.

The First Mobile Radio Systems

Two significant orders for this first generation VHF equipment were received in 1947 from business and industry. One order was for the very first UK private business two-way radio license for a VHF marine system installed in tugboats operating on the rivers Tyne and Wear in N.E. England. The other order was for the first UK motor vehicle based private mobile radio (PMR) scheme to be licensed in Britain under the Wireless Telegraphy Acts 1904 - 1926, to a Cambridge taxi company.

The early PTC102 mobile equipment was of typical military construction and appearance (silver plated brass chassis and black wrinkle paint finish) and consisted of a base unit housing the power supply rotary converters and three sub units containing the transmitter, receiver and modulator mounted on top. The matching PTC104 rack mounted base stations were mounted in black or grey painted Inhoff cabinets and used Lustraphone desk-top stand microphones, of a style which would have graced the BBC.

In 1948, PTL received its first substantial export order for 200 of the PTC102 mobiles for Holland. Another interesting potential application of the PTC102 was in a racing car and high-speed trials were carried out on the runway of a local wartime airfield with the set fitted in what at the time was a well known British sports racing car, the H.R.G. The idea was abandoned because of the lack of a suitable microphone and the excessive weight of the equipment involved.

In early 1949 PTL moved to larger premises with 5,000 square metres of floor space in Newmarket Road, Cambridge, occupying what was previously a Home Office gasmask factory and store. During 1948, J.O. Stanley, (the son of C.O. Stanley) was appointed Managing Director of PTL and in early 1949, J.R. Brinkley was appointed Technical Director with W.M. Pannell as Chief Engineer.

The other senior radio designer from the wartime period, Donald Hughes, was sent overseas to manage a new company - Coronet Industries, set up in Hong Kong by Pye to help them compete in future markets which would demand low-cost consumer products.

From then PTL rapidly grew and soon introduced new equipment for the marine HF markets, the aviation markets and the land mobile radio markets.

In close co-operation with the Air Ministry, the Ministry of Transport and Civil Aviation and the Royal Air Force, PTL had designed and was manufacturing Instrument Landing Systems (ILS), including the associated marker beacons, to full I.C.A.O. specifications. As well as R.A.F. airfields both in the U.K. and abroad, PTL eventually installed ILS systems at many international airports including London, Geneva, Moscow, Prague and Hong Kong.

One early mobile radio product of note was the PTC108, designed in 1949, which measured 29cm wide by 25cm deep and 13cm high and weighed 9.5kg. This was the first under-dashboard mounted set made in the U.K and had a modest 3-watt transmitter.

Between 1949 and 1951 a second generation of PMR mobiles and fixed stations was introduced, including the PTC112, PTC114 and PTC116 mobiles.

In these second generation equipment designs, double-button carbon noise canceling microphones were used and most of the VHF receivers were fitted with squelch (muting) circuits and effective noise limiters, the latter being essential because of the high level of interference generated by motor vehicles at that time. Also introduced at the end of 1949 was the PTC110 Dolphin which was the first of a series of marine sets, the PTC300 high power 100W fixed transmitter and the PTC810/820/830 VHF 6-channel FM radio multiplex link equipment, designed exclusively for export markets.

The Radio Systems Department

Because of the large number of variations in the customer requirements received for radio systems, a Radio Systems department was established, initially staffed by one engineer, Mr. H.E. (Charlie) Bottle, who joined PTL from the Home Office. One innovation that reduced the engineering lead-time for radio systems and also reduced the cost, was the introduction of a comprehensive range of "Standard Plans". From this range a customer could choose a radio system configuration which was near, if not exactly suited to his needs.

Initial VHF radio schemes in the UK used amplitude modulation (AM), although the principle of frequency modulation was by now becoming well established following its wartime use by the USA Military. The enthusiasm of J.R. Brinkley for AM led to the PTL policy to vigorously oppose any moves towards the adoption of FM in the UK, on the grounds of the better performance of AM at low signal levels.

At the time this attitude was fully supported by the British Home Office and the U.S.A. Department of the Navy. Although Brinkley inevitably supported wide channel bandwidth for multi-carrier schemes, he was very keen on conserving the spectrum used by standard, single channel radios, which in 1945 had occupied 200KHz of spectrum.

Decreasing the PMR Channel Bandwidth

By 1947, the RF channel bandwidth used by a PMR mobile in the UK had been reduced to 100kHz at low-band VHF, providing a two-fold increase in the number of PMR channels per MHz of spectrum compared to the pre-war Home Office arrangement.

Attempts to further reduce channel bandwidths were frustrated by other engineering problems. Although VHF receivers had crystal controlled local oscillators, the selectivity and stability of the Intermediate Frequency (I.F.) amplifiers became a limiting factor in the overall frequency stability of the receivers of the day.

Until the late 1940s, IF transformers were wound on a coil formers generally made of Synthetic Resin Bonded Paper, (SRBP). For the second-generation equipment which followed the PTC102 and PTC108, PTL dramatically improved the stability of the tuned coupled circuits in the receiver IF transformers. It was decided that an IF of 2.9MHz would be suitable for most of the applications at the time and that the double-superhet principle would be employed in all PMR equipments. A lot of work went into controlling the wire tension in the coil winding machines and instead of SRBP, the coil former used was a precision made, ceramic tube. High quality tuning cores, made of a suitable grade of ferrite material were supplied by Mullard and mounted on precision self-locking screw adjusters. Appropriate temperature compensating fixed tuning capacitors were added and the whole assembly was coated with a suitable varnish and baked for several hours to relieve stresses and to ensure mechanical stability.

As a result of this work, the channel bandwidth at VHF low-band was reduced to 50kHz, a four-fold increase in the number of channels per MHz since 1945.

The First "Reporter"

In 1951 a second generation, low-priced, low-power mass-produced dash mount mobile of reasonably compact dimension was introduced to replace the PTC108. This was the PTC116 Reporter. The Reporter was the first Pye mobile radiotelephone which did not use a heavy rotary motor-generator to obtain the necessary high voltage supplies and was fitted with a vibrator power supply instead.

The First PMR Portable

In the early 1950s, Brinkley became convinced that a hand-held transceiver would provide "VHF communications for the millions" and work was started on the design of portable equipment.

At that time Pye Telecom was unaware that back in 1942 Pye Ltd had designed, as a secret project, a VHF hand-held portable two-way radio for communications between British infantry soldiers and tanks. This equipment was not re-discovered until 1996 when the original designer came forward with an example of the design and the secret report which he had found in his loft.

In 1952 the existence of the transistor had only recently been announced and at that time the only practical active devices were the miniature B7G based valves with 1.4V heaters. These provided relatively low gain and because of their size and high filament power consumption, there was a limit to the number that could be employed in portable equipment. Accordingly, the design shared most of the valves between the receiver and transmitter sections and employed a stable and very effective regenerative IF amplifier. The resulting equipment was the PTC122 Walkiephone, the Company’s first VHF PMR portable. Early examples of the sets were given to the British expedition led by John Hunt for communications during the attempt on Mount Everest in 1953.

A wide area radio system was designed for UK air traffic control purposes, with the bulk of the equipment being supplied by PTL. This was very successful and similar schemes were planned for countries overseas. One of these was installed in New Zealand in 1953/4, using 6-channel multiplex links, carrying control signaling tones as well as speech, between the airways control centres and the ground/air radio sites.

During the late 1940s, Pye Ltd had worked on several development projects to replace the famous Military Wireless Sets No.19, (one HF project and one VHF). By 1948 Pye had an alternative HF equipment in prototype form called the C12, but the Ministry was not interested, preferring the hermetically sealed equipment concept which came to be known as the Larkspur family. Pye once again lost interest in military products. However during the mid 1950s it became clear that the planned replacement HF wireless set for WS19 in armoured fighting vehicles, (the C13) would be very, very late. As a result, in 1955 the Pye Wireless Set C12 was ordered to fill this role, and remained in service with the British Army until the late 1960s.

Long VHF Radio Links

In 1954, PTL received a valuable contract from the Burmah Oil Company for a long-range VHF link system in Pakistan. This was firstly to conduct a survey for a suitable route, and second to supply and install a 500km long, 6-channel multiplex radio link system. This link would provide speech and supervisory facilities for a new gas pipeline, which was being built between the recently discovered gas fields in Southern Baluchistan and Karachi. This was only the first phase of a system, which by 1959 was extended beyond Lahore, a total distance of about 900km - at which time it was the longest VHF radio link in the world. By 1955 a derivative product the PTC815/816 high performance VHF music link equipment was being sold.

Also in 1955 the PTC122 series Walkiephone portable and its companion designed for air-to-ground communication with gliders - the "Gliderphone", were made available to the public. These were adaptations of the set used in the conquest of Mount Everest.

Microwave Links

After wartime work on the first military microwave link, Wireless Set No. 10, and the contract manufacture in the early 1950s of a microwave link designed by the British Post Office, in 1955 PTL decided to enter the microwave link business themselves. After some early work on their own, a licensing deal was struck with the Raytheon Company of the USA, to manufacture one of their designs, suitably modified for the U.K. television system and employing British/European components. This equipment, the PTC1000A link which operated in the 5925 to 7425MHz band, was produced in fixed and portable (tripod mounted) form and the primary application was as a monochrome or colour TV link. ther 19 inch rack-mounted versions were made for long distance back-to-back connection for carrying broadband multiplex speech circuits and were supplied to the British Post Office. This led to the establishment of a dedicated microwave design laboratory, which over the next 20 years developed a number of low and high capacity link equipments. The microwave equipment was later manufactured at the new PTL factory in Haverhill, Suffolk.

In 1956 PTL established a factory in Ireland, at Finglas, Dublin, with Martin T. O’Dwyer appointed as General Manager. At the time it was named Telecommunications Limited and by 1957 the small engineering group at Finglas had designed and put into limited production a 1kW VHF transmitter, the PTC 3600. Other high power transmitters followed including 1kW equipments for medium wave broadcast applications as well as transmitters for use on the High Frequency (HF) bands. Eventually the whole factory moved over to the manufacture of antenna products, a niche in which the Finglas factory has continued to specialise, although now under different ownership.

Also in 1956 the third generation family of mobiles, the PTC145 Ranger series of AM VHF radiotelephones, was introduced in order to meet the new British, Canadian and U.S.A. Type Approval specifications. A later version of the Ranger was the first PTL VHF transceiver to incorporate transistors - two power devices being used in the power supply dc-dc inverter, which generated the high voltage supplies. Further work had been carried out on channel bandwidth reduction and the Ranger operated within a 25KHz channel spacing allocation, an eight-fold increase in terms of channels per MHz since the early radiotelephones.

Ten Years of Progress at Pye Telecom

For Pye Telecom, the highlight of the decade of the 1950s was a 1957 private exhibition in London entitled: "Ten Years of Progress in Telecommunications". The entertainment for important visitors was lavish and included a sponsored programme of music and ballet at the Royal Festival Hall.

Samples of all the products from the large range now manufactured by PTL were on show, including the first electronic telephone exchange to be marketed commercially. This 10-line, 2-link exchange used cold-cathode trigger tubes as logic elements and speech path switches. People from all walks of life crowded into the exhibition to see this exchange and in the evening of the opening day, its designer D.B. Delanoy was interviewed with the Managing Director J.R. Brinkley and the exchange was demonstrated on the national independent television channel ITV.

Also on show was a range of marine communications equipment including the British Navy HF/MF Type 619 transmitter and receiver Type CAT, designed to an Admiralty specification, a marine depth sounder and a fish-finder. Another novel item on display was a transistorised megaphone, the PTC1003 Transhailer, designed by Frank Grimm, (who was later to become Chief Engineer) which operated from dry batteries and was available in 3.5 watt and 10 watt versions. Also shown was the first popular priced "transistorised" car radio, using special valves produced by Mullard, which operated with anode supplies of only 12 volts, the single-transistor output stage employing a sliding bias arrangement which was quite efficient with acceptable audio quality. About this time PTL took over the design and manufacture for Pye Ltd of a range of car radios marketed under the Pye name.

In the further interests of conserving channel space, equipment from the new Pye Ranger series was demonstrated operating at channel spacings of 12.5kHz, giving a sixteen-fold increase in the availability of channels per MHz of spectrum since 1945.

By this time PTL employed about 2,000 people in five factories with a total floor space of 17,000 square metres. In addition, small assembly shops were set up in a nearby large vacant grocery store and in a disused bakery. Additional laboratory space was found in a disused village school at Fen Ditton - dating back to the last century - and the microwave laboratory was located in what was once a water mill near the village of Quy. In 1960, a new laboratory building was opened at the Newmarket Road site and the two off-site laboratories were moved back.

By 1960, the British Post Office had issued licenses to 1,500 private operators (excluding government departments) and more than 80% of all mobile VHF radiotelephone installations in Britain were Pye. There were 17,000 of the now famous PTC116 Reporter in service in 70 countries, the price of £85 having been maintained since 1951. Approximately 15% of all electronic and radio communication capital goods exported from Great Britain bore the Pye trademark.

Pye Telephones

Because of the great interest shown in the small 10-line, 2-link electronic telephone exchange, a new company "Pye Telephones" was set up to sell these. More effort was put into development and by mid 1960, a twenty-line exchange was in production. This was sold successfully on a rental basis in the U.K. and by mid 1963 a 100-line, 10-link exchange, with such facilities as tie lines and automatic radio connection was being sold.

The greatest achievement of the small team of engineers working on the development of electronic exchanges was the 1,000 line Private Electronic Exchange (PEX). This was a reed relay exchange, employing (link) programmed all solid-state common control electronics. Several of these exchanges were ordered by Electricity Boards in the UK and a 1,000 line PEX was installed at the main PTL premises, to handle all internal and tie-line traffic.

Other products were added to the product portfolio including push-button intercom equipment and public address amplifiers. Meanwhile the name "Pye Telephones" was changed to "Pye Business Communications Limited" which was later to be renamed "Philips Business Communications Limited".

The telephone exchanges and most of the other business/professional/industrial products manufactured by Pye, were shown at the "All British Exhibition", held at the New York Coliseum in June 1960 and opened by His Royal Highness, the Duke of Edinburgh and Richard Nixon, Vice-President of the U.S.A.

In early 1960, when nearly 40,000 vehicles in the UK were fitted with PMR, (the rate of expansion being about 100 mobiles per week), Britain’s first Public Mobile Radiotelephone service was opened in South Lancashire. This was a manual operator-controlled system employing one calling channel and four traffic channels. All the infrastructure equipment and many of the mobile units were designed and supplied by PTL.

The Pye Vanguard and Cambridge

Several new ranges of radiotelephone products were announced by PTL in 1962. Of particular note was the Vanguard range of high power boot mounted AM (25W) and FM (60W - 100W) mobiles.

To achieve the required narrow IF selectivity for 25KHZ channel spacing, these equipments were fitted with sealed inductor/capacitor (LC) 455KHz block filters, which effectively cured all previous problems of drift in conventional I.F. amplifier strips. The Vanguard range, the first samples of which were demonstrated to the Home Office and the Public Utilities within 6 months of commencing development, also used a number of transistor circuits mounted on small printed circuit boards, in addition to their valve circuits.

Also launched at that time was the first fully transistorised VHF receiver, used in the well known PTL AM10/FM10 Cambridge range of AM and FM equipments. The AM5D Transistor Reporter replaced the original PTC116 Reporter, and the HP1AM/FM Bantam, a 0.75W transistorised portable made an appearance. A comprehensive range of matching fixed station equipment was also announced in 1963, including the F27AM and the F60FM.

Telemetry Systems

Using techniques and modules developed for the electronic telephone exchanges, a range of telemetry and tele-control equipment was developed during the early 1960s and in early 1963, a comprehensive digital telemetry system employing UHF link equipment was installed for the Wales Gas Board. This system provided remote metering, flow control, alarm reporting and automatic data logging and was the first digital telemetry system operating over radio links to be installed in the U.K. The equipment gave good reliable service until 1974, when it was replaced by more modern equipment. Other large telemetry systems using similar equipment were installed for the Great Ouse River Authority in 1964 and the North Eastern Electricity Board in 1967. Telemetry systems were also installed in Penang (Malaysia), in Hong Kong and in the Middle East.

Following the Philips take-over of the Pye Group in 1967, and in order to concentrate all available resources on mobile radio, the electronic telephone exchange and the telemetry activities were abandoned in 1968, including the 1,000 line PEX project before any deliveries to the Electricity Boards had been effected. Near equivalents from the Philips range of switches were delivered instead.

The PF1 Pocketfone

One of the most significant equipments ever produced by PTL was the PF1 UHF Pocketfone, first demonstrated to the press in August 1964. This was a two-unit hand held equipment; a transmitter with a ‘pop-up’ rod aerial and a receiver with an internal aerial (making use of the tiny metal gauze over the miniature loudspeaker). Brinkley put forward the overall concept and it was his idea to operate in the UHF frequency band. Most people said it would never work because of the low power transmitter - 100mW, the low efficiency of the receiver aerial and the increased basic path loss at 450MHz. In practice the performance was well above expectations.

Mainly because of the shorter wavelength at UHF, there is less man-made noise and the greater effect of multi-path propagation means that the signals reflect and refract around obstructions and give better overall penetration. One of the more convincing demonstrations at the time was to hear the receiver working perfectly when inside the drawer of a metal filing cabinet!

In the field, the PF1 worked very well - even inside metal clad buildings and screened enclosures, especially those in which high radiated noise levels existed. These included very high voltage installations and power station dust precipitators. By 1975 over 70,000 Pocketfones were in use in the U.K. with 1,000 working on London Airport. 400 were in use on a radiating feeder system installed in the London Stock Exchange using 103 radio channels spaced 12.5KHz apart.

The Philips Take-over

In early 1964 a number of Pye Group Directors who had become discontented with the state of the Pye Groups’ finances, called in a firm of consulting accountants who soon produced a critical report. The Chairman, C.O. Stanley (now 67), resigned. Within one week of the very turbulent Annual General meeting held in November 1966, Philips, Thorn and GEC had made bids for the Pye Group of companies. Philips, however, soon acquired first, a 60% shareholding and later, an 85% shareholding, and finally took control of Pye in early 1967. Shortly after, Brinkley resigned from PTL, of which he was by then Chairman and Managing Director, and joined Standard Telephones and Cables (STC), which was part of ITT.

Scientific Management

On the 1st April 1968, Dr. John Westhead was appointed Managing Director of PTL and brought a new style of scientific management and control into PTL, which at that time had a headcount of 3178. Westhead, who came from A.E.I., was not previously connected with mobile radio, tightened up many of the fairly relaxed management procedures and introduced more formality into the decision making process, including in the areas of product development, marketing and sales.

Some said however, that the successful entrepreneurial atmosphere which had prevailed in the Stanley and Brinkley days virtually disappeared overnight. Nevertheless, the Company continued to be staffed largely by radio enthusiasts and continued to make good progress in all its chosen activities.

Pye Products in Space

In 1967 the Space Laboratory of Pye led by Don Weighton designed the special scanning receiver, which was carried on the UK Aerial III satellite. Its purpose was to explore the spectrum of galactic noise in the band from 2.0 to 4.5MHz where terrestrial observation is not normally feasible. By January 1969, equipment designed and made by the same group was orbiting the earth in eight different satellites, ranging from Aerial III and UK-1 to ESRO-2. Some of the experiments still functioned in the early 1990s, which says a lot for the design and build quality of these products, and for the skills and abilities of the people involved.

The Westminster

In the field of PMR the W15AM/W15FM Pye Westminster mobile equipment was introduced in 1967. This was the first all solid state PMR TX/RX. A very large range of AM and FM products, with a great choice of frequency bands, power outputs and different mounting arrangements was introduced over the next few months. This was a very well designed and reliable piece of equipment, which offered good value for money and was well liked in the market place. Many units were still in use by customers well into the 1990s, and the Westminster is still a well-respected classic design of the discrete component era.

Growing Pains

Pye Telecom had long outgrown the Newmarket Road site, had completely taken over the old Pye Radio Works factory (now called Cambridge Works) at St. Andrews Road, built a new factory in nearby Haverhill and had departments and laboratories scattered all around the City of Cambridge.

The AM mobile lab was located at Banhams Marina, as was also the Publications Dept. and the handbook store. The FM mobile lab was located at Gloucester Street, as was the Service Dept. Headquarters. The Spares department was located at Gwydir Street.

What was needed was one large industrial complex into which the whole operation could be amalgamated for maximum efficiency.

Site1 - The New Building Complex

In August 1970, Cambridge City Council gave formal planning approval for the construction of a major new Pye Telecom building complex of 19,000 square metres floor area, to be built on land owned by the Company on the south side of St. Andrew's Road, Cambridge. This area included the site of the original Pye Telecom building of 1947.

By March 1975 Philips gave financial approval for the new building which was budgeted at £5,000,000. In August 1975 site work commenced and the building complex was completed in early 1978 and in May of that year was formally opened by Lord Thorneycroft (a distinguished parliamentarian and Minister, at the time the chairman of Pye Limited). The opening ceremony was nearly ruined because three days of torrential rain had caused the river Cam to overflow on to land behind the site to a depth of several feet.

As there was no longer a need for the various other Pye sites around Cambridge City, the departments they housed were gradually moved to the new site (called Site1). Most of the original Haig Road Pye Radio Works factory was demolished for use as a car park.

New Products

New ranges of equipment continued to be introduced. The 1972 catalogue showed 22 mobiles, 21 portables, 20 fixed stations, 10 radio link equipments, 23 major systems elements and 16 antennas which were listed as current production items.

Amongst these items were: the SSB1000T 1kW H.F. SSB transmitter, the SSB130 HF mobile, a new range of dash mounted mobiles - the MF5/MF25 Europa range and the new Mascot 50/70/200 Operator Control System. The Mascot was the first equipment to employ electronic switching of speech circuits and electronic logic circuits for all control functions.

As of mid 1972, PTL had 33 Installation, Commissioning and Maintenance centres in the U.K. and had appointed qualified agents in 113 countries overseas.

In 1974 the M200 Olympic series of modular VHF/UHF mobile radiotelephones was introduced followed by the M256 Beaver in 1976 and a new Reporter MF6AM in 1977. The overall volume of this new Reporter being 1/10th that of the original valve set of the early 1950s, yet the transmitter output power was doubled.

The determined effort to reduce channel bandwidth requirements, which started in the earliest days of PTL, continued and in 1978 PTL reported on the successful conclusion of a project which included the design and manufacture of VHF AM and FM mobile transceivers using channel spacing of only 6.25KHz.

The 50 Watt M206 was launched in 1978 to compete with specific Motorola products (the Micor and Mitrek) in the Canadian and South East Asian markets etc. This had the highest performance receiver ever produced by Pye Telecom, giving 100dB adjacent channel selectivity and 80dB intermodulation, with good production margins. It utilised the chassis mechanics and heat sink of the duplex Olympic M204 and M214 equipments, when the product development was canceled and priority of development switched from the European CEPT duplex market to the international high power high specification market.

In 1978/9, UK Home Office sponsored trials took place of an SSB mobile radio system with channel spacing of only 5kHz. The equipments were based on the PTL M206X, which was the Company’s first frequency synthesised product. The M206X was an advanced development project to pilot the use of the new Mullard synthesiser integrated circuits and was based on the new M206 crystal controlled remote mount mobile.

Introduction of the Microprocessor

The end of the 1970s and the beginning of the 1980s were marked by the introduction of a proliferation of highly sophisticated mobile radio products. Examples were the ‘Assort’ equipment (designed by Mobicom in Derby) which provided for the automatic selection of the best-received transmission in a multi-site, multiple receiver radio system. Also the Pye Universal Encoder/Decoder Type UED 6 selective calling equipment went into production. This was the first PTL product, produced in quantity, in which a microprocessor was employed.


Going back a few years, in the early 1970s, work had began on the design of a decoder chip for paging receivers, using what was then state-of-the-art ‘integrated injection logic’ (I2L), technology. By 1979 a digital decoder chip had been successfully designed and manufactured, to which a miniature VHF superhet receiver was added resulting in a high performance digital pager measuring approximately 1.5cm x 2.5cm x 7.5cm, excluding case, acoustic transducer and battery. This product was called the National Pager.

Although the final product did not go into full scale production, at the time it was quite a remarkable development which later led the Company into the international pager business using the POCSAG radiopaging code, previously invented by Philips Research Laboratories and later to be re-named CCIR Radiopaging Code No.1.

Managing Internal Competition

Pye Telecom was not the only mobile radio company operating within the Philips Group world-wide, and during the 1970s, there had been conflicts between these various companies. This led to competition for funding, political friction, frustration and duplication of work. As part of a plan to circumvent competition and potential duplication, a Philips co-ordinating body, the Mobile Radio Management Group (MRMG) was established and headquartered in Cambridge to co-ordinate international product development and commercial activities.

As MRMG had little structural authority over the various competing international Philips radio communications companies, the results were mixed.

Things came to a head in 1979 with the development in Cambridge of the MX294 mobile for one market application and the development of the FM910 in Australia for a different market application. Each company applied for funding from the Philips parent, and much confusion resulted, as there appeared to be two different synthesised 25 Watt PMR mobiles in development at opposite ends of the world. In reality the two products were very different and positioned in separate segments of the market and targeted at different customer applications.

After the dust had settled, a major study was initiated by MRMG called the New Concern Mobile (NCM) project. The NCM project was intended to lead to the architecture and semiconductor component parts for a universal, worldwide, Philips ‘Concern Mobile’ and various other products including portables and pagers.

In the early 1980s, as part of NCM, a radio communications semiconductor design project was started in Geldrop, Holland. A number of engineers from various Philips organisations in several countries were selected to work together designing a set of integrated circuits (ICs) which would form the basis of future highly competitive, yet very sophisticated and high performance fixed, mobile and portable radios for private or public radio systems.

NCM Technology Applications

Although this project never resulted in components for conventional PMR equipment, several specialist radio communications ICs were designed, especially for the PG32 range of POCSAG personal pagers. At the conclusion of the project, the engineers returned to their respective countries and at Cambridge an Integrated Circuit Design Centre (ICDC), was established to build on their knowledge. At the Cambridge design centre, the follow-on advanced development project from NCM was designated CM42 (CM for Concern Mobile, and 42 as the ultimate answer to life, the universe and everything...., from a popular satirical science fiction TV program called The Hitch-hikers Guide to the Galaxy).

Much of the advanced development work from the CM42 and also the CM87 projects were later used used in the design of the FM1000 series mobiles, which was the first all-software controlled microprocessor based radio product from the Cambridge International Product Supply Centre (IPSC) as the site was later designated. The development of the FM1000 was not without its difficulties and took a significant amount of time, consequently the final product was not launched until 1989.

In the mean time the existing product range was still developing throughout the 1980s and selling in hundreds of thousands.

Trunked Radio Systems

In 1984 the E31-300, single or multi-site, multi-channel, wide area, radio system was introduced. With up to 8 base stations (radio channels), per site, this was the forerunner to today’s trunked radio systems. Fully automatic dialled interconnection between mobiles and a telephone system or mobile to mobile calls was provided.

The mobiles used were the new synthesised MX290 series, which became the first Cambridge designed mobiles to be microprocessor controlled (actually controlled indirectly by the internal signalling unit), and were fitted with a full keypad and a comprehensive status display panel. A large scheme was installed for the gas and electricity utility companies in Northern Holland. Later, in 1988, this system was up-dated with the M206 low-band radios and finally in the 1990s with the FM1000 range of mobiles.

Another product of special note, released in the early 1980s, was the very successful L700 radio link equipment, a slimline radio relay design conforming to CCIR specifications and operating in a wide range of frequency bands from 380MHz to 2.3GHz.

Even More Products

With respect to radios alone, the 1986 catalogue listed 12 mobiles, 9 portables 2 pagers, 18 fixed equipments, 10 link equipments and 2 SSB sets. In all over 100 major items were listed.

Philips Radio Communications Systems

From January 1986 almost every aspect of Pye Telecommunications business changed. Philips announced that a new business unit was to be created, based in Cambridge, which would control all radio communications activities world-wide in the Philips Concern (except Marantz). It was to be called Philips Radio Communications Systems (PRCS). The name Pye Telecom would be retained for a UK national sales organisation.

At the end of its independent life in December 1985 Pye Telecommunications Ltd. had 2200 employees, and sales representation in 102 countries of the world.

Sources: 1. Mr. D. B. Delanoy 2003,   2. The Story of Pye, Pye Limited, 1956   3. Bowen E. G., Radar Days, 1987, Adam Hilger, Bristol

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