On 9 Apr, 10:13, Roy Lewallen wrote:
Richard Harrison wrote:
Art wrote:
"The picture showed a seies of scan lnes across the screen at a slight
angle."

Yes. I think that is right but I learned about TV back in 1948 and
haven`t thought about it much since. As I recall, the designers of the
U.S. TV system decided to construct a picture consisting of two
interlaced fields. The first starts at the center of the screen at the
very top of the picture, sweeping to the right on a slight downward
slope, then retracing quickly to the lefthand edge of the picture. There
the next parallel but slightly lower line of field or frame starts being
written.

As I see it, the tilt or slope is strictly an arbitrary decision of the
designer but conformity is required of the standard to work within the
original system.

The tilt of the horizontal scan lines is simply a consequence of the
linear vertical deflection ramp being applied to the yoke at the same
time as the horizontal deflection.

Roy Lewallen, W7EL- Hide quoted text -

- Show quoted text -

I saw that as analagous to a horizontal beam i.e current with magnetic
electrons at right angles
in a time varying field, the resultant vector being at an angle with
respect to the horizontal sweepof the deflection signal. Either way,
since all vectors do not move in the same direction
the resultant vector cannot align with any existing vector.In this
case it presents an oportunity for the designer to have maximum
brilliance together with ramp. Who says you can't have your cake and
eat it to!
Art