Thanks! My main character is actually a teevee repairman circa 1961 fixing a 1957 RCA CTC-7C. So the teevee owner's complaint would be, "The picture's messed up. It's got a black bar that keeps rolling up and the sides are wiggly." So the repairman would right away know the main filter capacitor was bad? Why wouldn't he fix it at the home? Thanks!
As for the sneakers and hand in the pocket, the repair manuals I have say to do that. If no one ever did that, I won't have him doing it!!!!
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Originally Posted by old_coot88
 TThat sounds like a few of the old biddies i ran into during my years as a road techie (as well as an in-shop techie).
Well, first off i never knew a road techie who 'wore sneakers' specifically for electrical safety or kept one hand in pocket while working on a set in-home. I never knew one to routinely carry a tube tester into the home either. The test for a given symptom is to substitute the suspected tube(s).
But to address your specific scenario of a shrunken raster on the CTC-7, the very first thing the techie would know to do is substitute the 5U4s. But since there's no improvement, this indicates the 5U4s are not the problem. However the shrunken raster exhibits a hum bar, that is, a dark band that slowly scrolls vertically through the picture, accompanied by an S-bend in the sides of the raster that scrolls with it. This is the classic symptom of the main filter capacitor gone bad. The set would have to be shopped for this repair.
But note that the raster could not be "very small" and still display a picture. It would be pulled in maybe an inch or two from the sides along with the telltale hum bar. |