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Tornado TV TAB display unit: CRT module
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The crt assembly is coded as V22.498.78. Since V22.498 is on all the MRCS TV TAB DU equipment, it's logical that the crt module is part number 78 of the assembly. The assembly exists of a aluminum frame containing the glass crt tube with some connections to the 'environment'. 'Normal' crt tubes have a tube connector at the back of the 'electron gun' of the tube, but in this case the connections are moulded in some plastic. This makes the whole tube including wiring a replaceable part. It's likely the wiring is moulded to the tube to prevent damage due to the rather harsh environment in a fighter jet. (I don't think a 'normal' crt television would survive very long in a fighter jet...)
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There are two white dome shaped plastic caps placed on the top edges of the display unit. At first I thought they were some warning light. But after a little bit of power the current was relatively high so I stopped the test. After finding out the display intensity is automatically regulated according to the amount of light in the environment, it's rather logical that the two caps contain light sensors. I measures the electrical resistance and the resistance changes at changing light conditions. In low light conditions the resistance of the two parallel connected light sensors are 476 ohms. If there's a lot of light, the resistance increases to 511 Ohms. Hopefully I didn't destroy the light sensors with my 'DC voltage test'... I'll validate the correct working as soon as the device is functional again. Some images of the light sensors are shown below.
Here are the two light sensors shown.
After removing the green glass panel, the wiring of the sensors are visible.
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reverse engineering (raw data)
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