The Tektronix SD-51 Trigger-Countdown Head allows triggering a CSA 803/11800-series scope on signals from 1 to 20 GHz, at less than 6 ps RMS jitter.

Tektronix SD-51
20 GHz trigger countdown head
Tektronix SD-51 Trigger Head

Compatible with 11800-series scopes

Produced from 1989 to (?)

(All manuals in PDF format unless noted otherwise)

The SD-51 synchronizes a tunnel diode oscillator to a subharmonic of the input signal.

The project manager for the SD-51 was Murlan Kaufman.

Key Specifications

Trigger Bandwidth 1 to 20 GHz typical
Minimum Sensitivity  100 mVp-p
Maximum input Voltage  5 Vp-p
Input Impedance 50 Ω//1 pF
RMS Jitter 6 ps including instrument mainframe and SD-24 jitter