Ivory sheets :
Ted-Optalix type Saint-Germain by D. Werbrouck.

Restoration :
Un ancien radio réveil Philips by Y. Antonini.
Radio device found on a flea market near home, in the Lens vicinity (Pas-de-Calais), on May 10th, 2008. I got it for only 2 euros after negotiation! I did not find any references on it, the manufacturer label being largely extracted, leaving readable only its serial number. Stuck behind the casket, an other handwritten label indicated 110 V (I hope nobody made error with the mains voltage!). At home, the 220 V mains voltage implementation occured in 1979.
Vernir au tampon by L. Agez.
Certaines ébénisteries de nos récepteurs radio sont plaquées avec des essen­ces de bois qui méritent une finition soignée. J’ai osé la technique de vernissage que je vais vous dé­crire ci-dessous sur une caisse de Claronde Super Luxe. Puis, fort de cette petite expérience, j’ai persisté sur un Nox B400 de 1937 en placage de noyer.

Technical pages :
Penthode à transistors by G. Prieur.
In this series we will see how, with using electronic simulation software, we can save much time on circuit testing and avoid numerous unnecessary purchases. The example chosen here is to design, to simulate and to realize a circuit, as simple as possible, with semiconductor elements having the same characteristics (both static and dynamic) as a good pentode.
Les ondes radio naturelles by C. Beghin.
2e partie : La résonance de Schumann
This second part involves again the lightning wave emissions; however, they are instead triggered in the ELF range (Extremely Low Frequency). The frequencies under consideration are well lower than those of the tweeks which were seen in the first part as harmonics of cut-off frequency (1800 Hz on night time) of the TE (Transversal Electric) mode of the earth ground-ionosphere waveguide. The ELF waves described below are the TM (Transversal Magnetic) eigenmodes of the cavity, and they are known as “Schumann resonances”, named after their discovery by Prof. Winfried Otto Schumann, from München University (Germany), who predicted their existence in the fifties, and only confirmed one decade later.

Trick :
Ecouteur boîte de thon by D. Savel.
A high impedance earphone is indispensable to listen to the crystal radios or simple receivers, with no audio amplifier. I remember, when I was fifteen, to have desperately searched such an earphone, in vain, then tried to make one, unsuccessfully... The coil was impossible to build and the very thin wire, untraceable. Fifty years later, I should bring to a successful conclusion this early project.

Testimony :
Histoire d'un apprenti dépanneur by H. Fradin.
En 1940, j'avais 15 ans quand j'ai commencé un apprentissage de boulanger. L'année suivante, après une pleurésie, le médecin me déconseilla fortement de poursuivre dans ce métier. Je rentrai alors en apprentissage chez Monsieur Bertrand radioélectricien à Parthenay dans les Deux-Sèvres. Ce métier me plut. J'ai vite appris à dépanner les postes de T.S.F. en lisant beaucoup, en suivant les cours par correspondance de l'école de sciences appliquées de Tou­louse et en profitant des conseils des autres dépanneurs de l'entreprise.

Retro audio :
Un ampli pour guitare by C. Fabert.
The literature dealing with the audio amplifier conception is quite numerous. No question in this article to speak about new things, but to describe a guitar amplifier which can deliver enough power to play in apartment or in a small dancing hall. It will suit for an electric guitar with a squeaky-clean sound and for an electroacoustic one as well. Besides, this article is an excellent approach to train with the former tube electronics.

History of techniques :
La TSF partie 3 by J-C. Montagné.
We remind the necessity of slightly striking the filing tube coherer just after receiving a signal to make it able to receive again. The devices proposed by Lodge (vibrating blade striking regularly the tube) or by Popov (small hammer thrown against the tube by an electric bell electromagnet device) allow to separate Morse dots and dashes, in order to activate a telegraphic recorder. However, the radioconductor should be provided with battery cells and a potentiometer adjustment is necessary to improve the sensivity.

Press review :
Analyses des revues françaises et étrangères by P. Demerseman, J-C. Montagné.
Plus de 250 articles ont été publiés en 2010 dans les bulletins de nos collègues, Allemands, Américains, Anglais, Australiens, Hollandais et Suisses. Les titres des articles les plus susceptibles d’intéresser nos lecteurs sont référencés ci-dessous.