This scope has been built around 1968. This is a sampling scope with a bandwidth of 1 GHz which is really impressive. It is quite heavy for a fully transistorised scope. It has a sampling dual input and sampling timebase.
The 568 is and advanced mainframe scope. It has plugins for horizontal and vertical deflection. The mainframe does not contain an amplifier itself, the plugins are connected to the CRT directly. As a result its performance is only determined by the plugins used. My Tek 568 had a 3S1 dual trace sampling unit and a 3T77A sampling time base. The 3S1 is optimised for high frequency signals and has 50 Ω inputs. Quite something different from most scopes. Tektronix had 10:1 and 100:1 probes for it, having 500 and 5000 Ω input impedance, respecively, but they were not included with this one. So I'll have to find the somewhat unfamiliar input plugs and tinker some probes myself
This 568 was offered on the Dutch Forum on Old Radios in early 2016 by a retired electronic engineer and radio ham. It has been used at Philips Data systems to make high-speed performance measurements of digital IC's and computer circuits. He told me that at the factory a component tester used to be connected to it, but he didn't have that one. The scope came straight from his attick, he hadn't used it for over 20 years. He was selling it and hoped it would find someone who was interested in this kind of special equipment.
I haven't tried it yet. To be continued.