Re: A scary Baird T23.
The TRF unit has been refitted and is working very well indeed, shame about the CRT though, it's really dim.
The attached picture has been enhanced because what illumination there is on the screen has to viewed in almost total darkness, that tube will have to be replaced. But before doing that there's nothing to loose by giving it a tickle from a tube reactivator.
Note there is a problem with the vertical shift. The Baird timebase resembles a high power blocking oscillator, only one triode valve is employed in the frame timebase, a Cossor 41MP.
The oscillator transformer has pole pieces which extend out to the neck of the CRT.
The DC current though the primary of the transformer is cancelled out by an addition winding. The set under discussion has a mechanical picture shift assembly which can adjust the position of the focus coil, no amount of adjustment of this device can centre the picture so the picture displacement fault must be in the timebase.
The second attachment shows the picture shift mechanism.
DFWB.
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