The Tektronix SD14 is a dual-channel, 3 GHz probe sampler designed for high-impedance signal acquisition where a 50 Ohm acquisition system is not the optimal solution. The SD14 is designed for high-speed device characterisation such as ECL, CMOS, ACL and GaAs testing. The 100 kilohm input impedance and 0.5 pF capacitance results in very low loading of the device under test. The 7 V dynamic range and +/-3.5 V offset range, makes the SD14 suitable for testing digital logic families as well as most analog circuits. The SD14 consists of two samplers, each attached at the end of a 1.0 meter cable for easy circuit probing. The modular architecture of the CSA803C/11801C enables the use of extended samplers, bringing a new level of performance to sampling scopes. In conjunction with the 11801C and SM11 multi-channel unit, it is possible to configure up to 136 channels of high-impedance, high-bandwidth acquisition with measurement accuracy approaching 140 ps.