The Vectrex is a rare beast in the world of retro video games. Introduced in 1982, this was the only video game system to put a monitor right in the console, and it did so for good reason. This was a games system with vector graphics and rotating 3D objects, something that just couldn’t happen on the TV in the family room. A while ago, [John] dug his old Vectrex out of his basement and replaced a faulty logic board. The CRT was still broken, but with a little bit of research and a not-so-ugly kludge, he managed to replace the CRT in a Vectrex.
[John] found someone willing to part with an old CRT online, and after whipping out his credit card, the tube was on his way to his front door. This new tube wasn’t a direct drop in; The original Vectrex had small ears around the edges of the screen that served as mounting points. The new tube had no such ears. Now, a bit of plastic strapping holds the CRT in the chassis. It’s a bit of a kludge, but at least now [John] has a source of Vectrex CRTs.
While the rest of [John]’s repair work didn’t go as well – the Vectrex in question still has all the logic board problems it had when it was taken out of storage. This Vectrex does have a new CRT, and with a bit more work on rehabbing this old machine, it should keep on working for another thirty years.
Whenever you come cross an interesting CRT, make sure you snatch it up. Here’s another offering that uses a tiny screen for some classic MAME action.
[GK] had some old CRTs lying around, so naturally he decided to build an old school analog scope with one of them. Lucky for us, he’s been documenting his progress. Since it was a big project to tackle, he started out with Spice modeling to work out all the right values.
Prototyping the power supply took some custom transformer winding, but when done, the power supply did the job. Although he’s still wiring up the Z (intensity) axis, the scope is already capable of displaying signals and even text characters using a character generator he built earlier (see video below).
[GK] spends most of the time so far talking about the high voltage power supply design. For the particular tubes he had on hand he needed +200V, -400V, -550V, and 6.3VAC for the CRT heater. This is certainly not the typical Arduino-based digital scope that everyone builds at least once.
We love analog scopes for art projects, logic analyzer conversions, and gaming. Of course, if you don’t have an old CRT in your parts bin, you might consider trying a laser.
Continue reading “Homebrew Analog Scope Project Log”
[GK] picked up a few tiny 2″ CRTs a while back and for the longest time they’ve been sitting in a box somewhere in the lab. The itch to build something with these old tubes has finally been scratched, with a beautiful circuit with Manhattan style construction.
[GK] has a bit of a fetish for old oscilloscopes, and since he’s using an old ‘scope tube, the design was rather simple for him; there aren’t any schematics here, just what he could put together off the top of his head.
Still, some of [GK]’s earlier projects helped him along the way in turning this CRT into a monitor. The high voltage came from a variable output PSU he had originally designed for photomultiplier tubes. Since this is a monochrome display, the chrominance was discarded with an old Sony Y/C module found in a part drawer.
It’s a great piece of work that, in the words of someone we highly respect is, “worth more than a gazillion lame Hackaday posts where someone connected an Arduino to something, or left a breadboard in a supposedly “finished” project.” Love ya, [Mike].