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Blooming and shrinkage at the same time? wow, that's an odd one. However I may be able to help out by splitting the symptoms up for you.
First, check out the damper and HO section. Low voltage could be the cause for the oscillator drift and shrunken raster. Shrinking on the sides is almost always attributed to B+ boost problems with the Damper tube or HO tube. Check the tubes.
Poor focus, blooming, and dimming are caused by weak HV, bad HV rectifiers, poor or NO HV regulation. However if you are getting this symptom along with a 4 sided shrink, then I might go back to the power supply and check for bad solder joints. If this set has an inrush limiter in series with the transformer primary, it may going up in resistance. You can check by measuring the voltage at the primary of the transformer. If its less than the voltage coming out of the wall then trace it back from the transformer and see where the voltage drop is.
Another problem is the use of Fuseistors, or fuseable resistors. These were often used in place of circuit breakers or fuses in the B+ circuits of some color sets. They will usually be 7 ohms at 5 watts or something like that. They will sometimes increase in value as they warm up, killing the B+ voltage.
Measure the B+ after the rectifier(s), and see if it changes after the set warms up. Then you can get somewhat of an idea of where to proceed from there. Follow the B+ line and see if there is anything like a dropping resistor that might cause voltage problems.
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Jordan
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