Expectation of Convergence

[Unimatic1140]

Hey guys, I’m attempting to get the static and dynamic convergence properly set on my CTC9 and I was just wondering how well these vintage color sets were able to 100% converge. As you can see by the picture below I managed to get the convergence set OK except for the bottom two horizontal bars, the 2nd bar from the bottom is acceptable, but the last one the color bands really separate. Generally the picture is nice and clear, but words on the very bottom, such as the news scroll on CNN get somewhat blurry because of this misconvergence. Is this normal for a ‘59 set or could something be out of whack?

[andy]

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Originally posted by Unimatic1140
Hey guys, I’m attempting to get the static and dynamic convergence properly set on my CTC9 and I was just wondering how well these vintage color sets were able to 100% converge. As you can see by the picture below I managed to get the convergence set OK except for the bottom two horizontal bars, the 2nd bar from the bottom is acceptable, but the last one the color bands really separate. Generally the picture is nice and clear, but words on the very bottom, such as the news scroll on CNN get somewhat blurry because of this misconvergence. Is this normal for a ‘59 set or could something be out of whack?

I also see a few retrace lines towards the top.

You're almost there

[Chad Hauris]

I have been able to get just about perfect convergence on my GE 1964 round set. It is easier to get good convergence, I think, on the round sets than the rectangular tube sets.

Try touching up the vertical linearity and height and centring and horizontal centering...these can affect the convergence. It looks like your vertical linearity may be slightly off.

[Unimatic1140]

Thanks guys for your info and I will certainly check the vertical linearity. I did recap the convergence board and the three resistors on it test ok. But as Andy suggested there is a selenium rectifier stack on it, I was assuming it was working because I can get convergence over the most of the picture, but maybe it needs to be replaced. I replaced a set of two selenium rectifiers once before in the low voltage power supply of a ’52 RCA television, I used two 1kv 2.5A Silicone Diodes and then added a dropping resistor in series with each diode to bring the B+ down. I’m not sure what kind of voltage is expected at the output of the selenium on the convergence board as I don’t have the schematic in front of me at the moment, but would I need to use the dropping resistor(s) for this type of circuit too?

[andy]

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