Radio – Television – Electronics – HELPFUL HINTS FOR 1950 (Mar, 1950)
Radio – Television – Electronics – HELPFUL HINTS FOR 1950
Aâ€”Producing large-size images from TV screens of nominal dimensions, this glare-less, flat and extremely thin lightweight screen utilizes the Fresnel principle of magnification. Advantages are claimed to include good optical quality and freedom from edge distortion. The magnifying element of the screen is a thin sheet of Plexi-glas into which hundreds of tiny circular grooves are pressed. It includes a glare filter and enlarges the image from a 10-in. TV tube up to the size received on a 16-in. tube.
B and Câ€”High-fidelity amplifier, specially designed for those critical experimenters who assemble their own combination phono-radio sets. With the increased number of FM stations now on the air, and the wider use of microgroove records, a high-fidelity audio amplifier of the type shown in the photos is desirable. No technical knowledge is necessary to make interconnections. Photo B shows the simple controls, and photo C is a rear view with the top cover removed. Output impedances permit connection to any type of speaker, and to magnetic cutting heads of disk recorders. Push-pull 6L6 tubes give high output at low distortion.
Dâ€”Tiny hearing aid, demonstrated recently at Radiolympia in London, also includes a radio receiver for receiving one broadcast program.