The Tektronix 519 is a 1 GHz oscilloscope introduced in 1961. The 1 GHz bandwidth was achieved by driving the plates of the CRT directly with no vertical amplifier. This achieves a vertical deflection of ~10 V/cm. To achieve the 1 GHz bandwidth Tektronix also made a unique 125 Ω GR-874 connector which is not compatible with the commercial 50 Ω GR-874 connector. The 519 also came standard with a camera mount bezel. Only the center of the CRT was guaranteed for the bandwidth so the non-displayed portion of the CRT is covered by the bezel. Each bezel has the specifications for the CRT. The 519 on display at the museum has a vertical sensitivity of 9.46V/cm and a risetime of 300 pS.
The museum does not have any 125 Ω GR-874 connectors so we are driving the oscilloscope with a Type 106 Square-Wave Generator through a 50 Ω coax with clip leads to the input. This mismatch in termination provides some nice reflections for the display. The museum also has a 519 CRT on display as well.
The delay line is rigid and has a delay of only 45 nS. The actual delay line, called “Spir-o-line”, was not manufactured by Tektronix. It is called “Spir-o-line” because the center conductor is held inside the line with a spiral of polyethylene tubes (largely air).
This delay line, along with the longer CRT and large transformer required a larger and more robust mechanical package.
Stan Griffiths, one of the two museum founders, calibrated 519 oscilloscopes early in his career at Tektronix.
519 oscilloscopes were used by various agencies doing nuclear research in the 1960s. As such, some would become contaminated. Tektronix offered assistance in decontaminating an oscilloscope and the information can be found on the Radioactive Scopes page. The 519 was eventually replaced with the introduction of the 7104 1 GHz oscilloscope in 1978.
The Beautiful-Electronics-Blog (BEB) on YouTube has a BEB #62: Tektronix 519 Vintage 1GHz Oscilloscope (Part 1) video on the 519.