Thruster Triangular Loop: A Portable Antenna Worth a Look

A free antenna project from KJ6ER offers portable operators a reason to explore a different wire configuration.

What would make you pack a different antenna for your next park activation? More contacts might be the obvious answer, but deployment space, noise, and the direction you want to work deserve a place in that decision, too.

Greg Mihran, KJ6ER, has added the Thruster Triangular Loop to his collection of free antenna plans. His official project listing describes a right-triangle loop for 20 through 6 meters, with bidirectional gain through the loop, broad frequency coverage, and low noise pickup. Those are the designer’s stated characteristics; this article is an introduction, not a KE2YK field test.

Why directionality deserves a look

For a portable operator, the useful question is where an antenna puts its signal. Bidirectional means favoring two directions. That can be appealing when the stations you hope to reach lie along a useful heading, provided your operating site lets you orient the antenna accordingly.

It also makes the radiation-pattern plots worth studying before the first deployment. Which headings are favored on your chosen band? How does the pattern change as you move higher in frequency? A single description cannot answer those questions for every band and installation.

A different option beside the EFHW or vertical

If your usual portable antenna is an EFHW or a vertical, treat the Thruster as a project to evaluate against your own setup. Compare the complete installations: support requirements, occupied space, feed line, matching equipment, and time from opening the bag to making the first call.

The useful comparison is practical. Can you deploy it at the parks you visit? Can you point it where you want? Does the extra setup effort, if any, earn its place in your operating routine?

Look beyond the noise-floor reading

The low-noise claim is particularly interesting, but a quieter receiver alone would not settle the comparison. The test worth making is whether wanted signals become easier to copy. During an antenna comparison, listen to the same stations close together in time and keep receiver settings consistent. Note signal readability as well as the background noise.

Start with the original plans

KJ6ER describes his portable designs as computer modeled, home-built, and field tested. He also explains that the free documents are revised over time. Use the current Thruster construction PDF linked by KJ6ER as the authority for dimensions and assembly.

Before buying parts, check the specified supports, wire lengths, feedpoint components, feed line, and tuning requirements. In particular, do not interpret a 20–6-meter coverage statement as a promise of tuner-free operation throughout that range.

For hams who enjoy building and comparing portable antennas, the Thruster looks like a worthwhile candidate for the project list. The next step is straightforward: read the plans, assess the deployment requirements, and decide what you would want to measure on your first outing.

Original resources

• KJ6ER portable antenna designs and current project updates
• Thruster Triangular Loop construction plans

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Materials and tools for building the Thruster

The Amazon selections below come from the parts list in KJ6ER’s October 2026 construction plans. Check the selected size, wire gauge, connector style, and package quantity before ordering. Prices and availability can change.

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases.

• BNTECHGO yellow 18 AWG wire, 100-foot spool (paid link) — Sloping hypotenuse wire and associated pigtails.
• BNTECHGO orange 18 AWG wire, 100-foot spool (paid link) — Bottom crosswire; the contrasting color helps distinguish the two wire assemblies.
• Mueller BU-55 10A steel clips (paid link) — The construction instructions use three: one at the whip tip and two at the elevation pole.
• WAGO 221 inline lever connectors, 24–12 AWG (paid link) — Connections between the band-linked wire segments.
• MTUERANC 2-in/1-out lever connectors (paid link) — Two connectors for the separated corner assembly.
• Makita 0.080-inch round nylon trimmer line (paid link) — Nonconductive corner support segments; follow the plan’s separation arrangement.
• XHF 18 AWG / 1.0 mm² wire ferrules (paid link) — Recommended for durable wire ends used repeatedly in lever connectors.
• Klein ferrule crimping tool, 22–10 AWG (paid link) — Assembly tool, needed only if you do not already own a suitable ferrule crimper.
• 40-inch furniture-grade PVC tubes (paid link) — Optional support approach instead of a tripod; requires the matching caps, spike, and mount from the plans.

Additional components to plan for

This shopping list is not a complete antenna kit. You will also need a suitable telescoping whip, a 4:1 balun, not an unun, a suitable RF feedline choke, coax, a whip mount and support hardware, a separate elevation pole, and a 3/8-inch ring terminal. The PVC support option also requires matching end caps and a ground spike. Band labels are useful for field assembly.

KJ6ER specifies a 25-foot whip for the full 20–6-meter design; a 17-foot whip is an alternative for 17–6 meters only. Select the balun and choke for your operating frequency and power. The plans note that the listed LDG balun is not specified for 6 meters, even though KJ6ER obtained a match there, with potentially greater insertion loss.

Use the original Thruster construction plans for the specialist components, mounting details, wire-segment dimensions, and corner assembly. Band changes require changing the linked wire lengths and adjusting the whip; the antenna is configured for one band at a time.

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