More Cathode Ray Tubes
Cathode Ray Tube displays dominated electronic for over 100 years but have now become mostly obsolete. They are still amazing examples of engineering and applied physics with fascinating history and theory of operation. The top image (1) is of one of the last types of colour CRT manufactured. It has a flat face plate and a high-resolution shadow mask. known as a 'Flatron' it isn't a Trinitron and was made by Philips-LG with an inline gun but two focusing anodes.
The tube to the left (2) is a normal late colour TV tube made by Philips and shown here fully dressed.
Next (3) is one of 3 projection CRTs this being the blue projection screen. These use very high anode voltages. The screen face plates were liquid cooled to protect the fluorescent coatings.
All the above CRTs have used electromagnetic deflection. The (4) image is of a small Telefunken oscilloscope CRT. The coil on the neck of the tube is for trace rotation alinement. This tube also has a graticule etched internally onto the screen. This was common practice on high quality tubes reducing parallax error when measuring traces.
Colour CRT (5) is a small 5" portable panasonic tube. The shadow mask is less magnetic than normal and doesn't use a degauss coil.
CRT (6) is manufactured by Dumont (CDU 5SP7) and was from around 1951. This is a large CRT and unusually has two completely separate electron guns. It is thought to be for a dual-beam oscilloscope. Most later CRT oscilloscopes split the beam electronically with a 'chopping' circuit and were know as Dual trace. Some tubes split the beam and were still Dual beam, but used the one gun for focus and brightness. This one could have one gun switched off completely. This CRT also has a long-persistence phosphor.
(7) A whole range of didactic CRTs were once a popular educational introduction to particle physics. This is an example of a Perrin tube, demonstrating the charge on an electron, manufactured by Teltron. link to more information on the construction detail of each type of CRT.
Use the link on picture (1)
for even more CRTs!
