SCTV Clock Assembly Manual
1/24/22
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Initial Checkout
Before turning on the clock for the first time, inspect the bottom of the PC board for stray component
leads that may be shorting together different pins. Also check for unsoldered pins. Clean off the flux if
desired, using commercially available flux remover. (If you used no-clean flux solder, skip this step.)
Adjust all four pots to the center of their travel, with the dots at the 12 o’clock position.
Plug the wall adapter into the wall, then plug it into the DC power jack J1. The filament should glow
orange after a few seconds, and a Cathode Corner splash screen should appear on the CRT screen after
about 20 seconds. The display is likely to be very narrow.
Display Adjustment
Adjust the Brightness knob at upper left so that the display is bright enough to see but not overly bright.
Adjust the Focus knob at upper right to make the lines as sharp as possible.
Adjust the H Pos knob at lower left and the V Pos knob at lower right so that the display is
approximately centered.
Using a screwdriver, Adjust H Size and V size screwdriver controls so that the image fills the center two
thirds of the screen.
The display will probably be tilted with respect to the cabinet. Loosen the clamp screw and rotate the
CRT so that the numbers form a horizontal line. This can be checked with a plastic ruler against the two
tabs at either side of the center of the front face. Be sure that the felt is protruding 1/16” at the bottom,
and tighten the neck clamp on the CRT snugly.
Adjust the Astig screwdriver control to make the lines sharp as follows: Turn Focus counterclockwise a
bit to make the lines blurry. Turn Astig until the defocus is the same in both horizontal and vertical
directions; i.e., the line width is the same in all directions. Now readjust Focus till the lines are sharp.
Turn the big encoder knob and see that the time is displayed in different formats, and you will see a few
other screens. Go ahead and play some Pong against yourself using the position controls as paddles.
You will need to reset the Pos controls to center the display after playing a game, since they do double
duty as the game paddles and the position controls.
Final Assembly
Installing the rear cup and cap
The rear cup and cap are to be installed only after you are happy with the CRT alignment, since this
adjustment is not possible with these pieces in place.
The cup is the small flexible piece. Its paper needs to be peeled off all the little slots as well as the large
areas. This is best done with a piece of sticky tape. Gorilla Tape is recommended, although other brands
of duct tape are likely to work.
To remove the paper coating from the flexible pieces, use the tape procedure. Set the plastic piece on the
edge of a table with the edges of the slots facing you, with a cotton cloth under it.
