Poste Parisien 

24 May 2024 tbs.pm/80562

 

The Poste Parisien Studios

 

Cover of World-Radio

From World-Radio, dated 1 November 1935

Having received an invitation to pay a visit, I presented myself at the appointed hour at the studios of the Poste Parisien at 116 bis Avenue des Champs-Elysdes, Paris. I was received by M. Querville, the “Régisseur” of the station, who introduced me to Mlle. Lola Robert, the “speakerine,” with whom I had a pleasant interview. This took place in the waiting room, where friends who accompany artists to the studios have to wait, as they are not allowed in the studios during broadcasting. They can, however, listen to what is taking place, as there is a loudspeaker in the waiting room that can be switched on or off and the volume control of which can be adjusted to suit the convenience of the visitors. A concert was being broadcast at the time of my arrival, and consequently it was not possible to enter the studios until it had terminated.

“Publicity” Items

While I waited, M. Querville supplied me with information concerning the activities of the station. I learned that the intervals at 8 p.m., 8.45 p.m., and 9.30 p.m. each evening were devoted to “publicity” items with a background of music. These items are limited to forty words each, and during the broadcasting of them the music is faded into a faint background, to return at full force immediately afterwards. Publicity is a necessity as far as the private stations are concerned, and the State stations have banned it from their programmes. Attempts are made to render the publicity palatable, and this musical background is one method. It succeeds too well in some cases, for, on mentioning my visit to the studio to a French friend on the following day, I discovered that frequently the musical background was appreciated so much that the publicity and the fading of the music became aggravating. These musical publicity intervals last for about a quarter of an hour.

Authority to give experimental television transmissions has been applied for, and it is hoped that this will soon be granted.

Poste Parisien logo

The first studio that I visited was the small one used for chamber music and theatrical transmissions. Originally the walls were covered with asbestos, but later large square panels of three-ply wood were added to increase the resonance, so that they now have a chess-board pattern, partly in asbestos and partly in three-ply wood. Other boards are suspended from the ceiling to prevent echoes, and the floor is covered with linoleum. A loudspeaker has been installed for use during rehearsals; also a phonograph. There are the usual silent signals which enable instructions to be given while broadcasting is taking place. In one corner of the ceiling there is a glass roof, which enables those in the control cubicle above to obtain a view of the studio. This cubicle is occupied by M. André Alléhaut during the theatrical productions, and the glass roof of the studio extends partly into it a few feet above the level of the floor, almost like a glass desk. M. Alléhaut is in charge of all the theatrical productions, which take place about twice a week. The usual days are Thursday and Sunday, and he has a stock company at his disposal.

Mlle. Janine Press and Mlle. Yvonne Galli, the “Muses” of French wireless for 1934 and 1935, respectively, both belong to this stock company, which from time to time gives propaganda performances in provincial towns.

The large studio has a height of two floors — actually the third and fourth floors of the building (the other floors being occupied by business offices not connected with the Poste Parisien). It measures 32 ft. by 59 ft., and contains a cinema screen on which the actualities and Silly Symphony films are projected and described by the “speakerine,” Mlle. Lola Robert. Experiments are continually being made with the walls, which have been different each time that I have seen them. They are covered in a sugarcane fibre, of which a double coating has been applied, with wooden panels in spaced positions, as well as by means of two large portable boards on wheels which can be moved about the studio until the desired effect is obtained. Also on the walls, and suspended in the middle of the room, there are curtains which can be drawn or closed as desired.

 

Headshots of three people

(Left) M. Marcel Laporté, announcer (formerly “Radiola” of Radio-Paris); Mlle. Lola Robert, “Speakerine;” (right) M. André Gaudelette, announcer

 

When I last visited this studio, the electronic organ of MM. Eloy Coupleux and Armand Givelet was installed at one end, and many concerts were given on this organ by noted musicians. This has now been dismantled, the tone having been found too dry and not satisfactory from a musical standpoint. There were several microphones in the studio: one suspended from the ceiling and capable of being raised, lowered, and moved in any direction to any part of the room; another, attached to a crane-like apparatus, called the “Giraffe,” which was also movable to any position in the room. The microphones are of German Reiss pattern, and can be modified to suit the high or low notes of a singer. The control cabin is at the side, from which the interior of the studio can be seen and the transmission heard by loudspeaker. The air in the studio is constantly renewed, the regulating apparatus for this being in an ante-room.

Recorded Programmes

A further room is used for talks, another for announcers, and others are used for gramophone transmissions, effects, accumulators, and control post. Many transmissions are recorded on a film about a quarter of an inch wide for reproduction at a more convenient time later. This is done by means of an Austrian machine called the selenophone, and it possesses the great advantage over disc records of being easy to cut and join again, thus enabling unwanted portions of the transmission to be omitted. From the control panel, transmissions can be taken from the four studios, the gramophone table, or the relay line and passed on to the transmitting station at Les Moliéres. There are special safeguards to prevent the transmissions being mixed, unless a special switch, called the mixer,” is used, by means of which the programmes of two studios can be transmitted simultaneously or faded into each other, a fading and amplifying switch existing for each studio. At this control panel signals can be sent to the studios, transmissions can be amplified and controlled in other ways, and a system of lamps of different colours indicates the parts of the installations that are in operation.

M. Jean Grunebaum and M. Roger Sallard are the Directors of the Poste Parisien station, including studios in the Avenue des Champs Elysees and the transmitter at Les Moliéres.

 

A view across a studio with drums and a piano

One end of the large studio

 

The Poste Parisien Transmitter

 

Transmitter building and tower

General view of station building and aerial

 

Transmitter tower

Transmitter tower

Poste Parisien was the first French private station to transmit on medium waves, Radio-Paris, which in those days was a private station, having made use of long waves only. The original station, with a power of 500 watts, was installed at the offices of a French newspaper on the roof of which two pylons of modest dimensions supported the aerial. The present transmitting station at Les Moliéres was constructed and inaugurated officially on April 25, 1932. The original wavelength was 328 m., but it was afterwards changed to its present figure of 312.8 m.

The power and situation of the new station were matters to which much thought had to be given. The effects of fading on the wavelength assigned to the station were considered, and it was decided that a power of 60 kW would be suitable in order to give satisfactory reception to listeners over the greater part of France. But a station of this power could not be erected in a large city without causing serious interference to reception from all other stations. On the other hand, it was necessary that the studios should be situated in Paris and they would have to be connected to the transmitting station by means of cables specially designed for the transmission of music and a wide range of frequencies.

Choice of a Site

A search was therefore made for a site far enough from the city to avoid “wiping out” other stations and near enough to be connected with the studios by special cable. Other qualifications that were desired were height, open ground, a minimum of obstacles such as forests, industrial centres, etc., between the site and Paris, and reliable supplies of water and electricity. The territory fulfilling the most of these requirements was ultimately found at Les Moliéres, about twenty miles from Paris and situated on a plateau nearly 600 feet high. About sixty acres of land were acquired, and the station itself, together with the houses for the staff, and the garage, occupy about ten acres.

One important feature of the station is the way in which all essential parts of the installation are duplicated to avoid interruption of transmission. The result is that interruptions are reduced to a minimum represented by the time necessary to switch over from one set of machinery to another. This duplication begins with the supply of electric current to the station, which comes by underground and overhead lines from two different stations, St. Remy-les-Chevreuse and Fretay, each supply being A.C. at 15,000 volts.

Power Supplies

These power lines terminate about a quarter of a mile from the main building, and thence underground lines convey it to the machine room on the ground floor of the two-storey building in which the transmitter is housed. There, suitable switchgear enables power to be applied to the three main transformers — one with an output of 15 kVA at 190 volts for the lighting system; the second with an output of 90 kVA at 190 volts for the motors of the D.C. generators and the circulation pumps. The third transformer is three-phase-twelve-phase and supplies current to the main rectifier, the power being 300 kVA. By means of remote control, the output voltage of the rectifier can be raised, while running up the transmitter, from 5,000 to 12,500 volts in forty stages.

The filaments of each of the sixteen power valves require a current of 80 amperes at 20 volts, and this is supplied by eight separate generators, each of which heats two valves. Two other generators provide 600 volts for grid bias and 1,200 volts for the plates of the low-power valves respectively, while another generator supplies current at 16 volts for the filaments of the low-power valves. AU these machines are in duplicate, enabling the alternate circuit to be switched on in case of a breakdown.

The anode supply of the water-cooled power valves is obtained from the twelve-phase transformer and the rectifier, the latter being of the mercury-vapour type, the smoothed output being at 11,000 volts. For valve cooling, distilled water is used, which comes from a tank on the roof. After passing the anodes, the water is cooled by traversing pipes in a cooling tank situated at the back of the building, and is then returned to the roof tank again.

The Transmitter

The system of modulation used by the station is called the “deéphasage” system, and its principal advantage is said to be its high efficiency. Thus a power of 60 kW (aerial) is obtainable from a total input of 220 kW instead of 300 kW — a substantial economy in energy. The transmitter consists of several stages: a master oscillator generating a high-frequency current, a separator stage, a modulator stage consisting of four sections (a non-modulated stage, a modulated stage, an intermediate stage, and a “déphasé” stage), an amplifying stage, which receives the programme from the studio prior to its being passed on to the “déphasé” stage, and three amplifying stages after the “déphasé” stage, each being in duplicate. The initial modulation at low power is that of “anode control,” which I believe is similar to that used in Great Britain. All these stages are screened and enclosed in a metal case with the exception of the amplifiers, which are in four separate metal cases to the right and left of the other stages and forming a compact group with them.

Electrical equipment

The output stage and tuning circuits of the transmitter

Aerial System

The last stage is connected to the aerial by an overhead feeder line which is surrounded by an earthed wire screen. The aerial system consists of two masts, each over 400 ft. high and about 600 ft. apart. The stays supporting the masts are insulated, as also are the bases of each mast. The aerial is at the back of the station, and between the masts is the aerial transformer house.

The whole of the transmitting apparatus is on the first floor, the generating machinery, pumps, etc., are on the ground floor. The main control desk is on the first floor, together with all the necessary measuring instruments. A system of coloured lights and electric bells act automatically to advise the engineer in case of a breakdown in any part of the installation and to indicate the position of the fault. At the same time safety devices come into operation and switch off the power supply.

The special cable connecting the transmitting station at Les Moliéres with the studios in the Avenue des Champs-Elysees, Paris, is 22½ miles long and contains two pairs of programme lines, three service telephone circuits, and a pair of lines for television transmissions. Correcting networks have been introduced into the “programme” lines every half-mile (approximately), with the object of maintaining good quality.

 

Your comment

Enter it below

A member of the Transdiffusion Broadcasting System
Liverpool, Thursday 18 July 2024