Circuits for removing retrace lines

[bigaudioal]

Anyone know of a source for procedures or schematics for adding circuits to remove retrace lines for Admiral chassis 21K1 and 21L1?

I found this procedure below with attached photo, but it was kinda hard to follow what exactly needs to be done. Specifically how/where to wire in the pot and connecting the voice coil winding in series with vert. deflection yoke?

ADMIRAL 21- and 22-series Chassis

Retrace line elimination
(see Fig. 5 attached).

Retrace elimination by means of fixed values has often proved unsatisfactory mainly due to tolerances used in manufacturing and aging of tubes. The following method provides an adjustable control so that a pulse of correct amplitude may be applied to the picture tube.

1. Connect a 100,000-ohm potentiometer (part No. 75B13-12) across the primary winding of a speaker transformer (part No. 79C33-1).

2. Connect the voice coil winding of the speaker transformer in series with the vertical deflection yoke as shown in the figure.

3. Cut the green lead going to pin 2 of the picture tube. Connect the portion of the lead remaining on pin 2 to the center arm of the potentiometer, and connect the other portion of the green lead to an outer terminal of the potentiometer. Adjust the potentiometer until the retrace lines are removed. If the retrace lines do not disappear or they become brighter, change the green lead from one outside terminal of the potentiometer to the other.

With the contrast control set at minimum and the brightness control at maximum, the potentiometer should be adjusted to the point where the retrace lines just disappear.