310
The Tektronix 310A is a compact portable oscilloscope with a 3" (7.5cm) round CRT. It is a single-trace, single-timebase scope. It is a tube scope but does not have a fan. The 310A is hinged at the rear, allowing reasonably convenient access to the circuitry despite the fact that it is packed more densely than in other Tektronix scopes of the era.