In 1978, an oscilloscope was a rare piece of equipment for most hobbyists. It’s likely that they were even harder to come by in the Soviet Union. Still, [Thomas Scherrer] managed to get his hands on a Soviet X1-7B combination oscilloscope and spectrum analyzer (even though he’s not entirely sure if it’s a spectrum analyzer).
The Soviet scope stands out with its Cyrillic front panel. Despite the differences in appearance, the scope also features an interesting rotating bezel around the circular CRT. You can view a video of the 8.2 kg scope below.
Upon opening up the device, the internal components seemed fairly conventional for a scope of that era, utilizing all-transistor circuitry. The rotating bezel also controls what appears to be a large mechanical switch and cavity, or possibly a significant mechanical variable component.
When [Thomas] attempted to power it on, there was a censored audio and a loud noise immediately after plugging it in. Troubleshooting revealed a burned smell coming from the power circuitry, although no obvious issues were found upon initial examination. Oddly, the fuse didn’t blow, and even more perplexing, the unit was off when plugged in.
It was later discovered that the input power filter had leaked to the chassis, leading to the failure. Despite the inconvenience, this was preferable to the risk of a shock from a hot chassis due to the ground connection. The second attempt to power it on was more successful.
Ultimately, the device did function to some extent, although [Thomas] did not fully explore some of the peculiar features present. While classic boat anchor scopes are popular, Soviet instruments are not as commonly seen, at least not from the perspective of those of us on this side of the Atlantic.
Occasionally, some Soviet-era computers do surface. Regarding the fuse not blowing, it was found to be shorted before the fuse, which is a reminder that fuses don’t always behave as expected.
Image Source: Thomas Scherrer OZ2CPU Teardown @YouTube
