The 1S2 is a sampling/TDR plug-in for 500-series scopes. Like the 1S1, it is a complete sampling subsystem and uses the mainframe merely as a power supply and low-speed display. Unlike the 1S1, it contains pulsers that allows it to perform time-domain reflectometry (TDR) measurements. The 1S2 has two 50-ohm pulsers, one of which is active at a time. One puts out a 250mV pulse with 50ps risetime. The other puts out a slower 1 volt pulse. The sampling bridge is a feed-through type. For TDR measurements, the signal from one of the internal pulsers is fed through the sampler, and out to the the transmission line being tested. Returning pulses are detected as they pass back through the sampler, and they are reabsorbed by the 50-ohm impedance of the pulser. Waveform output can be to the CRT of the mainframe and/or to a plotter or low-speed data acquisition device via banana connectors on the front of the 1S2. The 1S2 was introduced in 1967 and was sold through 1971 or 1972.
- Tektronix TDR Measurement Concepts
- 50 Years of RF and Microwave Sampling, Mark Kahrs
- Picosecond Pulse Labs Application Note 4: TDR