If you have an old mini CRT television, you can turn it into a retro clock with minimal effort and basic components. However, there’s also another option… building one. But before we surrender to the high voltage, I think it’s worth visiting Matt Evans’ portal who decided to take the CRT tube from an old Sony viewfinder, connect it to a Raspberry Pi Zero, and craft a fabulous transparent enclosure around it.
How do you remember CRT screens? Do you feel nostalgic at the thought of them, or are you glad to have left them behind? Obviously, opinions vary widely: some desperately search for monitors and televisions in good condition to hook up their retro gear and consoles, while others have a rather negative view of that technology.
Enthusiast Matt Evans admits he initially belonged to the second category. Growing up in Europe, he was exposed to the 50 Hz and the 15.625 kHz whine of the PAL standard. He believed CRTs were heavy, delicate, blurry, noisy, and distorted, not to mention the electric shocks and the implosion of the tubes. Over time, his opinion of CRT screens improved greatly, but he also loves small screens, and when he managed to rescue the tube from an old Sony HVF-2000 viewfinder, he decided to build a mini CRT TV.
How to build a mini CRT TV with 1980s hardware
The idea is to show off the TV from every angle, and for that, nothing beats a transparent case revealing its components. After extending the cables to stack the viewfinder’s PCBs one on top of another, Matt had to reverse the horizontal deflection cables to get the image oriented correctly (the original viewfinder sits at 90 degrees to the CRT face and uses a mirror).
The rest of the circuit isn’t particularly complicated. Two DC-DC converters generate 8V for the CRT and 5V for the Raspberry Pi Zero, loaded with retro shows playing in a loop. Fortunately, the Pi Zero has RCA output, and it connects directly to the CRT without much fuss.
Matt devotes an entire chapter to the enclosure, designed in OpenSCAD, and anyone interested can download the file from the official page. A power switch, a 12V input, and an encoder (which he added to 'change channels' in the future) adorn the back. The lack of ventilation might catch your attention at first, but with a total power draw of 2W, there don’t seem to be any temperature issues with the mini CRT TV. The final result is excellent, and if I ever find a tube like that, I’d love to build something similar. What do you think?
Official site: Click here. Source: Hackaday.
