514
The Tektronix 514 is a monolithic general-purpose oscilloscope. It was designed by Tektronix engineers Bob Davis and Dick Rhiger. Using a distributed amplifier it provides frequency response from DC to 10MHz. Prior to the 514, customers had to choose between an instrument with 10MHz bandwidth (the 511) or an instrument with DC response (the 512). The 514 provides DC response and 10MHz bandwidth.
It has no thermal cutoff.