04-18-2016, 07:53 AM
Hate to say it but it looks like the pix tube to me too. A brightener might help. It will raise the heater voltage slightly causing the gun to give more emissions. Low high voltage will cause blooming when the brightness is increased and loss of focus. May be a combination of both. A picture tube tester should verify, unless the tube is gassy.
If I could find the place called "Somewhere", I could find "Anything"

Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44