Quote:
Originally Posted by radio nut
Well, I tried taking pics again, and with my phone I cant get a real good image but I will kep trying. I subbed in The Hot ,and high voltage rectifier and had to readjust horiz. hold but noticed a cleaner picture. found a nos damper put it in and now the problem is changed a little.
There is about a 1 to 1.5 inch darker than the rest of the picture bar on the left and everything in it is fuzzy and magnified. when a person walks across the screen their shape changes. I will see about putting the original damper tube back in and see what happens and borrow a digital camera for pictures.
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Radio Nut,
Did your original symptom look like Phils' very clear photo above?
In it, there is no shading, just two vertical lines.
There is no image fold or magnification (stretch).
The left side vertical lines may be speckled or they may be black or they may be white or a mixture of the three.
If not, you did not have Barkhausen!
This tube switch reduced the Barhausen, but created a new problem that I underlined in your reply. Correct?
On your circa 1950 Muntz, you have four controls grouped together on the right side of the back of your chassis. The bottom left of those four is the Horizontal Drive trim capacitor . (One side of the trim capacitor is grounded and the other connects to a 100 ohm resistor going to pin 5 of the 6BG6, a 470K resistor going to the ground and a small capacitor going to horizontal oscillator transformer.)
Did you turn this trimmer capacitor before the fold problem appeared? If this not the same problem you had before the tube swap, try adjusting the trimmer with the new tubes in place.
A single horizontal fold is usually horizontal drive, that adjustment. The fold may be on the left, but more often is near the center of the screen.
Adjust the trimmer for least fold (and best linearity), while measuring the voltage ground to cathode on the 6BG6. You want that adjustment to be on the side of the range where there is the least voltage on the cathode (in other words, with the tube drawing the least plate current.) The need for readjustment is not unusual when replacing the Horiz Output tube.
There may be other causes, but an incorrect drive setting is the most common.
James