Antenna End Insulator ("Dog Bone" Insulator)

Antenna end insulator, for attaching end of wire antennas to support lines. Designed for print-ability, structural strength, minimal chafing of wires and lines. When printed at 70% scale (recommended size) or more, exceeds typical support line and antenna wire break strengths. Hole size is 10mm at 100% scale, 7mm hole at 70% scale, etc.

Size and design provides long leakage path to easily contain potential end voltages. Typical voltages one can expect at the end of a dipole:
@ 100 watts up to 600-700 volts.
@ 1500 watts up to/around 8000 volts.

RF thermal effects should not be an issue for any station up to 500 watts. Unknown if any issues above that.

End insulators are important components of any wire antenna and provide a stable capacitance to maintain antenna tune. Attaching antenna wires directly to support lines or structures is not recommended.

Outdoor, load-bearing, support application. Do not recommend using PLA or ABS.

Note: antenna insulators do NOT provide any form of lightning protection.

Designed with Fusion 360.

73!

Print instructions

Category: Electronics Print Settings

Printer Brand: Prusa

Printer: i3 MK3

Resolution: .30

Infill: 50% rectilinear

Filament: Prusament PETG Black recommended for UV resistance
Notes:

6 perimeters. 6 top and 5 bottom layers.
Designed to print laying on side, with hole facing down.
Infill at 50% rectilinear, at 90 degree orientation. You want long, end-to-end path for infill.
Perimeters and long internal fill path provides strongest longitudinal strength.

Overview and Background

In my journey to design an insulator for myself, I learned that the subject of insulators is
quite a bit more interesting and considerably more involved than I ever thought it would be.
I put together a PowerPoint presentation with some of what I learned for my local radio club, and also uploaded here for your interest.

Related Designs

See also: Antenna Guy Insulator.

See also: Wire Clamp for 14 gauge Antenna Wire.