Un nouveau récepteur de trafic OC
by Daniel Maignan.
Amongst the alleys of the famous Bonneval swapmeet, a large metal cabinet lying on the ground caught my eye. I thought I recognised a Sadir-Carpentier R254 short wave radio, similar to the one I’d used for listening to morse traffic from Interpol and military training sites in the 70’s.
I quickly haggled with the seller and secured the set for a modest sum. Back home I realised that, although the front panel was practically identical to the Sadir, the interior was a completely different story, with a, let’s say, less professional design.
Today, as I write this article, I still don’t know its make or where it came from. Note, that it still sports a Dymo label indicating the Medium Wave International phone distress frequency (2182 kHz).
My technical curiosity at its peak, I decided to undertake its restoration without delay.
Introductory courses :
L'Électronicofil s'initie à la haute fréquence
by Gérard Prieur.
HF is a popular area in electronics but which requires certain precautions to be taken. For the benefit of beginners, we will try to outline here some basic principles and practices which will enable straightforward construction of projects without the need for sophisticated equipment.
Et si on apprenait à compter en binaire ?
by René Nisolle.
It is based on the binary representation of numbers, some basic arithmetic functions and some logical tests (equal to or not equal to) which lead us down one route or another. The man-machine interfaces, becoming ever more sophisticated, and even more the plethora of self contained and often ‘buried’ applications, have made us forget these basic notions.
This article focuses on the difference, often misunderstood, between figures (symbols) and numbers (quantities).
History of men :
Les écoutes du lieutenant Delavie
by Alain Caupène.
Je viens de lire dans le n° 92 de Radiofil magazine l’excellent article d’Alain Levasseur sur les téléphones de campagne dans lequel il fait allusion au lieutenant Delavie. J’ai écrit cet article sur cet homme, un « pays », qui est paru il y a quelque temps dans La Pioche ou Radio-REF ou les deux, je ne me souviens plus !
L’ensemble de TPS est de ma fabrication et seul le manipulateur pliant est d’origine (modèle des États-Unis en fer).
History of techniques :
Evolution de la radio au seuil des années cinquante
by Daniel Maignan.
Construction of broadcast transmitters and receivers was effectively ceased in France during the Occupation, due both to lack of base materials and the bans imposed at the time. At the end of the war things restarted very slowly. But the research laboratories had not ceased their activities (whether abroad, or underground in France) and produced several innovations designed for military applications.
The construction of aircrafts and remotely controlled fuses as well as shells and teleguided bombs necessitated the development of compact transmission and reception equipment with exceptional reliability.
Finally let’s note that the mode of frequency modulation adopted by more and more transmitters in America already enabled high fidelity reproduction of musical frequencies in France, on the very short wave band.
Construction d'un voltmètre électronique
by Michel Dutrone.
In the early 80’s I started to build a valve voltmeter using a circuit taken from a publication by Perlor Radio entitled « Electronic Measuring Equipment ». This was also published in issue #1096 of Le Haut-Parleur magazine.
My project never saw the light of day, due to lack of time and components.