The 17Z3 is an efficiency diode for television line scan and the design dates to the early 1950s. This was a popular design and was made by many companies under various Type designations.
The rectifier is specified as having a peak inverse voltage rating of 4,500 Volts, and a peak current rating of 450 mA.
The stitched anode. The two plates are turned outwards at the ends to increase the surface area for radiating the heat generated.
To insulate the heater from the cathode when at very different potentials there is a ceramic tube inserted into the cathode tube and the heater sits within.
Here the top mica components show the cathode ceramic liner and the connection between cathode and top cap.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 73 mm tall.
