The С1-91 (Cyrillic; latin transliteration S1-91) is a general-purpose 100 MHz scope made by the Soviet Research and Development Institute of Radio Measuring Instruments in Vilnius (present-day Lithuania). It takes one horizontal and two vertical plug-ins.

Vilnius Research С1-91
100 MHz mainframe
С1-91 front view

Produced from 1977 to (?)

(All manuals in PDF format unless noted otherwise)

It was produced in various versions at the Vilnius and Minsk plants, individual blocks were made in Bryansk. It was the company's best-selling model from 1984-1989, with 22780 units produced, at an average price of 3800 rubles[1].

Key Specifications

Bandwidth 100 MHz
CRT 17LO1I, 100 mm × 120 mm
Power 150 W (switchmode PSU)
Weight 15 kg
  • three plug-in bays
  • thirteen plugin types
  • digital readout