The Tektronix 016-0506-0x is a chart recorder module for the 1501/1502/1503 time domain reflectometers.
The 1501 used the -00 model, the 1502 and 1503 the -01.
016-0506-00 Chart recorder from 1501 TDR
Recorder open for loading of paper
Chart recorder bottom
Rear of chart recorder