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Adjustment of a Begali HST III

Published: Jan 31, 2026

Summary

A guide to adjusting a Begali HST III.

The Begali HST III (High Speed Telegraphy) is a precision instrument designed for single-lever paddle operation and sideswiper (Cootie) modes. Unlike standard dual-lever paddles, the HST III requires a specific approach to geometry and tension to unlock its full potential.

Begali HST III key top view

This guide covers the mechanical adjustments required to tune the key to your specific operating style.

1. Vertical Arm Alignment

Before adjusting gaps or tension, you must ensure the lever is vertically aligned. Because of the HST III’s unique geometry, the contact strip on the lever must meet the stationary contact points perfectly flat, not at an angle.

The Adjustment Mechanism: Locate the vertical adjustment screw situated on the bearing block (often found near the pivot point of the arm).

The Procedure:

  1. Visually inspect the contact area where the lever touches the side posts.
  2. If the lever is too high or too low, the contacts will touch only on the top or bottom edge, reducing surface area and potentially causing erratic electrical connection.
  3. Turn the vertical adjustment screw to raise or lower the arm until the contact faces are perfectly parallel and flush with the stationary contacts.
  4. Lock this setting in place (if your model includes a locking nut).

Lab Note: Proper vertical alignment reduces contact resistance and minimizes the “scratchy” feeling during high-speed transmission.

2. Contact Gap Spacing (Travel)

The gap determines how far the lever must travel to close the circuit. The HST III allows for independent adjustment of the left and right sides.

Begali HST III contact adjustment screws

The Adjustment Mechanism: The two large, knurled silver screws on the side posts serve as the stationary contacts.

The Procedure:

  1. Back off: Loosen the locking rings on the contact screws.
  2. Zero Point: While holding the lever in the center (neutral) position, gently turn the right contact screw inward until it just touches the lever (you will hear the tone if connected to a keyer).
  3. Set the Gap: Back the screw out slightly.
    • For High Speed (QRQ): A very tight gap (approx. 0.001" to 0.002") is preferred to minimize motion.
    • For Ragchewing/Cootie Mode: A slightly wider gap allows for a more rhythmic, relaxed swing.
  4. Repeat for the left side.
  5. Lock: Once satisfied, tighten the locking rings to secure the posts.

3. Magnetic Return Force (Tension)

The HST III uses repelling magnets rather than springs. This provides a “non-linear” force that feels crisp and reduces fatigue. The tension determines how quickly the lever returns to center after a keystroke.

The Adjustment Mechanism: Look for the knurled screw adjusting the magnet position (usually located on the side or rear of the block, moving a magnet closer to or further from the lever arm).

The Procedure:

  1. Increase Tension: Turn the screw to move the stationary magnet closer to the lever arm magnet. The stronger magnetic field creates more resistance and a snappier return.
    • Best for: High-speed operation and preventing “contact bounce.”
  2. Decrease Tension: Move the magnet away from the lever.
    • Best for: Sideswiper (Cootie) mode or operators with a lighter touch.
  3. Balance: Find the “sweet spot” where the key creates enough force to stop the lever from bouncing across to the opposite contact when released, but not so much that it causes finger fatigue.

4. The Switch: Paddle vs. Sideswiper

One of the defining features of the HST III is the ability to change electrical modes without rewiring.

The Mechanism: Locate the toggle switch on the base of the key.

  • Paddle Mode: The left and right movements trigger the “Dot” and “Dash” lines independently (for use with an electronic keyer).
  • Cootie/Sideswiper Mode: Both left and right movements close the same circuit (Straight Key line). This allows you to key manually by moving the lever back and forth.

5. Maintenance and Cleaning

To ensure the settings above remain effective, keep the contact surfaces clean.

  • The Paper Trick: Slide a piece of standard printer paper between the contacts. Close the contacts gently on the paper and pull the paper through. This removes invisible oxidation and oils.
  • Avoid Abrasives: Never use sandpaper or files on the gold/silver contacts, as this will ruin the plating.

Summary of Screws

Screw Location Function Result of Tightening (Clockwise)
Side Posts Contact Spacing Reduces gap (closer contacts)
Magnet Holder Return Force Increases tension (harder touch)
Bearing Block Arm Height Raises/Lowers arm alignment