High Amplitude Pulse Generator
The Tektronix High Amplitude Pulse Generator is a pulse generator plug-in for the TM500 system.
The High Amplitude Pulse Generator was produced in at least two different versions. The early version uses an external charge line. The later version uses an internal charge line consisting of approximately two meters of semirigid coax, coiled up to fit inside the plug-in.
According to Dennis Tillman,
[The High Amplitude Pulse Generator] was designed around 1978. It has a GR connector [for an external charge line] on the front panel to allow you to adjust the pulse width to whatever you want.
It outputs a 0 to 250 mV to 0 to 25 V variable amplitude pulse in 5 steps. [...] The rise time is <300 ps into 50 Ω.