Login:

Password:


Lost password
How to join us
Retour  l'accueil
 
The club The magazine Classified ads Useful addresses Radiomail Schematics library I am lost
 
The magazine
Radiofil magazine is the only 68 page French radio magazine with a bimonthly publication.
> Magazine presentation
> The latest magazine
> Anciens numéros of Radiofil magazine
> Anciens numéros of the Bulletin of the AEA
> Anciens numéros du Bulletin de l'AEA 1re série
> Anciens numéros of Rétro-phonia magazine
> Rechercher un article dans le sommaire général
> Articles in download
 
Surfing
Événements
> Radio junk and exhibition diary
> Radio junk and exhibition reports
> Event announcement
Schémathèque, notices, documentation
> Accéder au service
> Contenu des CD et DVD Rétrodocs
La boutique radiofil
> Library
> Composants
> CD et DVD-roms
> Boîtes de tubes vides
> Reliures pour le magazine
Téléchargements
> Calcul d'un cadre à deux enroulements
> Articles du magazine
Radiomail
Rétro-forum, le forum des passionnés de TSF
Magazine
> Présentation du magazine
> The latest magazine
> Les anciens numéros of Radiofil magazine
Useful addresses
> Radio shops
> Musées
> Associations and radio-clubs
Websites about radio
> France
> Europe
> États-Unis
> Other countries
Who are we ?
> Présentation du club
> Portrait gallery
> Tarif des adhésions
> Adhérer en ligne
> How to join us
> Contact us
 
 

Presentation
Contents of the magazine
Sommaire général
Submit an article
Download
Contents de Radiofil magazine 91
<< Previous March-April 2019
Next >>
Couverture magazine
 

Ivory sheets :
Le poste Ergos 770 by Dominique Lambert.

Realization :
A 3.5 MHz spark transmitter by Jean Cudraz.
The transmitter I will describe here is the fruit of research and tests over several years, having started with a Ruhmkorff coil. Then, considering that the early 20th century pioneers could communicate over long distances, I thought I could try to recreate a spark transmitter of that era, around 1910, with what I had to hand. I am a licensed radioamateur (call sign F1HR), which means I can transmit and be heard by other amateurs on permitted wavelengths. I have a large delta loop aerial (triangular in shape) for the 80m band (3,5MHz), which is essential for good performance with this transmitter. I choose a wavelength of 84,5m (3,550MHz) which suits my aerial. I then had to choose the tone for CW transmission, which is 1000Hz.
An FM tuner with lamps by Bernard Perier.
During my engineering studies in Paris – that must have been in 1963 – my classmate once whispered : “I’d really like to find out what a transistor hi-fi would sound like”. This remark set me thinking. Transistors, yes, I was familiar with these – I had one which I used to listen to “Salut les Copains” and “Pour ceux qui aiment le jazz” on Europe No 1 – but what might a true high-fidelity system consist of ? Careful study of electronics magazines of the time (Le Haut-Parleur and Radio-Plans for example) soon gave me the key to the puzzle. This was to give each separate element a well defined function : turntable and cartridge, radio reception, signal preamplification and amplification, speaker enclosure (stereo was still seldom mentioned), ensuring that each element performs as well as possible in its rôle. You then just had to connect them together to get perfect sound, hence the metaphor of a chain and its links. From that point, using the valve amplifier that I had previously described in Radiofil magazine #64, it followed that the transistor FM tuner I had at the time wouldn’t satisfy me much longer ; although there was nothing wrong with its performance electronically, its grey painted sheet steel cabinet no longer matched the warmth of the wood effect cabinet of the amplifier.

Trick :
How to simply measure an intensity by Pierre Adam.
Mesurer la consommation d'un appareil électrique ou électronique alimenté par des piles cylindriques ou des accumulateurs.

Memory :
My long career in the radio by Jean-Pierre Tonnelier.
In 1956, still at school and already interested in vintage radio, I was lucky to meet a radio service engineer from a Philips retailer in Charenton-le-Pont in the Val-de-Marne area, where I lived. Every now and then on a Thursday afternoon, I loved to go to the shop basement to tinker around with radios. My teacher, who I admired greatly, would get me to change a few components in the sets – potentiometers, electrolytics, … and to thank me for my help he’d let me have some bits and pieces, which made me happy.

In the course of Web :
Over the forum by Serge Logez.
Biasing of output tubes
In this edition, the subject concerns the biasing of low frequency power valves.

History of men :
The Polydict saga by Christian Don.
From 1947 to 1980, the small French company Polydict specialized in the manufacture of wire, then tape recorders. While its core market was office equipment for corporations and administrations, it also developed high end tape recorders that could easily compete with Revox ! Here is its story.

History of techniques :
Principles of magnetic recording of sounds by Daniel Maignan.
Nous allons étudier dans le présent article le processus d’enregistrement et de reproduction tel qu’on l’a utilisé dans les enregistreurs magnétiques à bande.

Atelier :
A three-tube reaction SW receiver by Daniel Maignan.
This circuit diagram has been sourced from a magazine from the 50’s. Before publication in Radiofil magazine, it was prudent to construct a mock-up to verify the functionality of the assembly, which was done and enabled optimisation resulting in some improvements. The most modern form of a regenerative detector consists of an ECO oscillator (Electron Coupled Oscillator). But the drawback of all these forms of detector followed by an LF stage lies in the fact that the aerial has a significant effect on the tuning and “threshold”, a particularly annoying problem on CW or SSB ; in addition, the signal from the oscillator is widely radiated. To solve these problems, a simple and effective solution is to add an aperiodic HF amplifier stage at the front end.

The club The magazine Classified ads Useful addresses I am lost Schematics library Planning of events Reports Links Member area
© Radiofil 2004 - 2019