![]() ![]() In parallel one other standardization took place. The valve was introduced mid 1958 (together with its EC86 equivalent for parallel 6,3V heater supply), and first tuners appeared in 1960. The PC86 offered 14mA/V at 12mA anode current and 175V anode voltage. ![]() This in turn resulted in smaller grid-to-cathode gaps and ultimately almost twice higher transconductance gm of the triode. The frame tolerance was 5um, the wire positioning tolerance 0,2um. ![]() This allowed much finer grid windings, typically 10um wire with 50um spacing. With this concept, the structural stability of the grid windings was provided by a separate molybdenum frame, with the thin grid wires wound around it tightly. The technical breakthrough required was the Philips PC86 UHF triode, using the new " frame grid" (, sometimes also called "guided grid", in Dutch spanrooster) construction. Secondly introduction was effectively awaited till good technical solutions were available, avoiding the "trough of disillusion" as experienced in the US. Firstly VHF television broadcast only started in earnest during the first half of the 1950-ies and it took a few years before an actual channel shortage made itself felt. It was only in 1965 that the FCC made UHF tuners mandatory in all US TV sets.Įurope followed a few years later for two reasons. Many of the stations went bankrupt in the following years and by 1958 only 9% of television sets contained a UHF tuner (vs. Results were disappointing, however, mainly due to bad receiver performance, the resulting short range and limited area coverage. The large scale roll-out of UHF broadcasting started in 1953-54, with a few hundred stations nation-wide. The US allocated 60 channels from 470 (Channel 14) to 884MHz (channel 83) which were fully compatible with the VHF NTSC (CCIR-M) standard, so 30Hz frame rate, 525 lines, negative modulation and FM sound in a 6MHz channel bandwidth. For television this was the Ultra High Frequency (UHF) band which formally runs from 300 to 3000MHz. The natural solution to this problem was - and still is today! - to move to higher frequency bands, where more bandwidth is available. Naturally this issue occurred first in the US, where TV broadcasting had started as early as 1943 and the number of broadcasters was highest. This was aggravated by the need to avoid adjacent channel interference, which meant that not all channels could be transmitted from the same location, and careful nation-wide frequency planning was required to avoid interference. Once television broadcast took off it became clear that the number of channels allocated to it, (in Europe) 4 in VHF I and 7 in VHF III, was much to low to accommodate all potential broadcast programs. In the slip stream of all this also the Philips tuner became one of the leading solutions, with volume manufacturing at multiple locations. On top of that it supplied all components also to other manufacturers, further increasing the volumes and economy of scale. ![]() Increasing volumes in multiple factories, and increasing third party sales.īy this time Philips was establishing itself as the leading European TV set maker, based partly on its strong vertical integration with in-house manufacturing of the picture tube, all valves, speakers, transformers and passive components, partly on the fact that the company was active and a leading player in almost every European country, in many cases with local manufacturing and brand name.mechanical channel selection memories, building on the success of the first Memomatic.UHF reception, providing substantially more bandwidth and an increase of channels.PCF86 and PCF801 pentode-triode combi valves for the mixer-oscillatorĪt the same time other developments are taking shape:.PCC89 and PCC189 variable-mu cascode amplifiers.In this series of improvements the PCC88 was the first of the frame grid valves, which offered a very clear improvement due to their smaller internal construction, and valve developments in the coming period will be dominated by frame grid valves: The sensitivity had step-wise improved with the introduction of ever new valves, moving from the EF42 to the EF80, ECC81, PCC84 and PCC88, in combination with the PCF80 mixer-oscillator. The modules had steadily grown in functionality and maturity, covering up to 12 channels in the VHF domain, with internal AGC and if desired AFC control. We're now at the end of the 1950-ies, after almost 15 years of TV tuner development within Philips. ![]()
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