LDG Balun Surface Mount

Overview

A single-piece bracket that holds an LDG RBA-1:1 balun or RU-9:1 unun (or others). The back plate is mountable on a wall or tube, and the unit drops into an open-top cradle at the bottom. No straps, no zip ties, no tools needed to remove the balun.

On the Air

The problem this solves is a balun hanging off its own connections. Left loose, the weight of the unit plus the coax pulls on the binding posts and the SO-239, and in wind it swings and works the wire connections. Mounting it solid to the mast or a wall takes all of that strain off the electrical connections and puts it on the tube instead.

It also makes setup repeatable. The balun lives in a known spot on the mast, the feedline dresses the same way every time, and the antenna wires come off the binding posts at a consistent angle. For a portable HF station that gets set up and torn down repeatedly, that removes one thing to think about.

Printed in PETG so it holds up to sun and heat outdoors. ASA, PCTG, etc. are other options for filament. Not PLA.

Print Settings

• Printer: Bambu Lab X1C, 0.4mm nozzle

• Material: PETG. Chosen for UV and heat tolerance, and because it flexes rather than snapping when the mount gets knocked.

• Layer height: 0.2mm

• Walls: 3

• Infill: 15%

• Supports: none required

• Orientation: bottom flat on the build plate

Hardware and Assembly

• 2x #8 hex-head self-tapping screw, length to suit your situation.

Steps:

1. Hold the bracket against the surface at the height you want and mark the two screw locations through the counterbored holes.

2. Pilot drill both marks to suit your #8 screws and your tube wall thickness.

3. Drive both screws. The counterbores let the heads sit below the face of the plate so they do not bear against the balun.

4. Drop the LDG unit into the cradle. It seats on the floor of the pocket with the binding posts facing up.