GEC C2110 SERIES
When the picture first appears, there’s a bright horizontal
band, about lin. deep, at the bottom. This disappears after a
couple of minutes. The picture is then normal except that
the very lowest of captions are half lost below the bottom of
the screen. This later fault was apparent before the bright
band first started to appear.
The bright band is foldover when the field timebase first
comes into operation, and the general problem seems to be
lack of field linearity. Make sure that the field output stage
mid -point voltage control P454 is correctly set, then check
the thermistor TH451 (VA1034) in the output stage emitter
bias network and the field charging capacitors C457 (47µF)
and C458 (22µF).