Summary

Its all about the procedure for adjusting a bug key.

Details

Begin the procedure by performing basic checks, ensuring the arm moves freely, contact posts are tight, and dot and dash contacts are properly aligned and clean.
Next, make initial adjustments by setting the lever rest position and defining the initial lever dot travel (e.g., a 0.015 inch gap between the LEFT STOP SCREW and the lever for the Original model) using the stop screws.
Adjust the initial dash travel to match the dot travel, set the initial dot contact position so the contacts are just closed when oscillation stops, and set initial dash and dot spring tension.
Proceed to fine adjustments, ideally using an analoge Ohm meter to check continuity; adjust the DOT CONTACT SCREW until the meter reads 50% of full scale during dot oscillation, confirming a 1:1 dot:space ratio.
Adjust the DOT TENSION SCREW until the arm returns quickly to the damper wheel and stops completely without bouncing, which is critical for preventing scratchy dots.
Finally, connect the bug to a practice oscillator for a final checkout, ensuring that the dots and dashes are clean across the entire operational speed range.