The D5-100W is an interesting and unique 1.5 inch cathode-ray tube. Originally it was produced by Telefunken specifically for Sinclair's first production miniature hand-help pocket television that was launched in 1977. This was the model that predated the famous flat Sinclair television.
The tube also found uses in a miniature video monitor made by Sinclair and miniature oscilloscope, also made by Sinclair. Subsequently other manufacturers adopted the tube for television and oscilloscope use most notably NLS Ltd who produced a range of miniature oscilloscopes based around it. In more recent years it has also found a use in camera viewfinders and in various miniature portable medical monitors which can be worn by the patient.
The construction of the tube is interesting and can be revealed by close examination. The neck and body of the tube are made in two halves from vacuum formed mouldings which are then sealed together with separate pressings forming the screen and the hard-pin base assembly. The latter also carries the electron gun.
Manufacturing closely resembles techniques used for lamp manufacturing. The EHT requirement is of the order of 2 kV. Another unusual feature for a modern television tube is that it employs electrostatic deflection.
The tube is still produced in limited quantities in the form of the slightly improved D5-100WB. In these recently produced tubes the internal graphite coating, which forms the final anode, extends all the way up to the screen.
The tubes all use standard white television phosphor. For oscilloscope use a blue or green graticule/filter is placed in front of the screen. The tubes have a very small spot size and very high quality high resolution television pictures can be displayed.
The X deflection plates and the two getter holder rings.
The precision focus system.
The Y deflection plate.
The end window envelope is 32 mm in diameter, and excluding the base pins is 104 mm tall. The screen end is 45 mm X 35 mm