When first switched on the picture fills the
screen as normal, but gaps at ether side of the picture soon begin to develop. After about five
minutes these gaps are at least 2in. wide. I have replaced the PY82, the PL81, the PY81
and the EY81. I have also changed the width control, VR7. None of these measures, however, have effected a cure.-F. T. Howe (Saffron Walden. Essex).
It is surprising that replacement of the PL81 and
the PY82 did not right the fault as these are most often the cause of the symptoms described. How ever, if you are sure that the new valves are in order, you will have to check the 3.3kR screen
dropping resistor. the 0.1pF boost line capacitor and the 80pF 6kV tubular capacitor from the PY81
to the width control (on the transformer panel, being the right hand one of the two).