How to correct picture distoration

[ModernClassic]

Hi,
I got this no so old " funai " colour TV ( 10-15 years ? )from a friend and found that I like the picture quality over the modern ones with digital circuits.
The problem is the picture is distorted - reverse of a barrow: widened at the 4 corners and narrow at centre.
I seemed to recollect that there are some adjusters at the picture tube neck for that.
Would someone direct me as how and which control to adjust?
Thanks

[Chad Hauris]

I know on older sets that use the delta gun CRT there are "pincushion" adjustments to correct this...but I don't think that there are magnetic components on the inline CRT neck for pincushion distortion. I can't say that I have personally seen this problem on any inline CRT sets.

[andy]

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[ModernClassic]

Originally posted by andy
On a modern TV there will be a circuit to correct this type of distortion (pincushion distortion). It's usuallt located in the horizontal yoke return line. Often the picushion output transistor shorts. I wouldn't spend too much time on a Funai. They are the worst of the worst quality. 10-15 years is exceptionally good for any Funai product.

Oh, but..............this Funai is the only 25" tv that is norrow enough to fit into my bookcase! Sound like I just have to live with its distortion!
Thanks
Mc

[wa2ise]

On older sets there's a pincusion transformer like device that in yours must have failed. Look for a transformer that has three windings arranged like that of a 3 phase power transformer. Instead of a single winding bobbin inside an E I core, it will have three bobbins in a row and the core will have E's with 7 fingers instead of 3.

The problem of pincusion stems from the fact that parts of the picture tube screen lie at differing distances from the CRT guns. For a given amount of vertical deflection, when the beam is swept horizontally it would trace a curve instead of a straight line. So this pincusion transformer is used to add some of the horizontal sweep waveform (after some processing) to the vertical, and visa versa. B&W sets used magnets to do this but that would make convergence worse in a color set.

[kc8adu]

just how bad is the pin distortion?
many cheap sets use a pin corrected yoke and no adjustment is possible.
and funai is the bottom of the barrell.
that set was built for the walmart tv shopper.
bet it has poor regulation too.
image size changes with light/dark sceen change.