About Greyline Performance | Sun Valley Antenna Maker

About Greyline Performance

Built by Operators, for Operators

Greyline Performance designs and manufactures off-center fed vertical dipole antennas for HF amateur radio operators who need real performance from real-world installations — HOA lots, small properties, rooftop and waterfront sites where conventional radial-field verticals can’t go. The work is done in Sun Valley, Idaho. The antennas are used worldwide.

How we got here

Greyline started with a problem. The founder — Jon KL2A, a competitive contester and DXer — was operating from a suburban property where a conventional radial-field vertical wasn’t going to happen. Burying 200 feet of radial wire was off the table. Putting up a tower was off the table. The choices were compromise the antenna or compromise the operating.

Neither was acceptable. The answer turned out to be the off-center fed vertical dipole — an architecture where the radiator works as a self-contained circuit rather than depending on a buried ground system. Elevated feedpoint. No radials. Multi-band coverage from 160M through 6M with an ATU. Permanent, maintainable, and small enough that it disappears as an antenna and shows up as a flagpole.

The first builds went to fellow operators. Word moved. The product line followed.

What We Build

The Greyline Approach

Every Greyline antenna is a vertical dipole — an OCF radiator working against itself, not against the soil. Five core sizes (12, 16, 20, 24, 28 feet), two product lines (DXF flagpole-style for HOA installations, DXV bare-pole for rooftop and open-yard installations). All five sizes cover 160M through 6M from a single feedpoint with an ATU. No traps. No coils. No buried radial fields.

Construction is 6061-T6 aircraft-grade aluminum, 2" OD, with graduated wall thickness — thicker at the base where bending stress peaks, thinner toward the top where reducing mass at height reduces dynamic wind loads. Stainless steel hardware throughout. Every wind rating is calculated against ASCE 7-10 and is height-specific — the 12-foot model carries the highest rating, the 28-foot the lowest. The math is published, the methodology is published, and the OD is published. We expect operators to verify the engineering. Most do.

The Standard

Why Greyline Cites Its Sources

Antenna marketing is full of unsupported claims. Greyline’s standing rule is simple: if a claim cannot be traced to a named published source, it does not run. The physics references behind every Greyline design decision are public — Robert Zavrel W7SX ( Antenna Physics: An Introduction , ARRL 2020) and John Kraus W8JK ( Antennas , McGraw-Hill) for the foundational work; Rudy Severns N6LF for ground systems; Walter Maxwell W2DU for transmission lines; Roy Lewallen W7EL for the EZNEC modeling tool that informs every gain figure we publish.

The full bibliography — physics, propagation, low-band, modeling, HOA zoning — lives at The Shelf We Read From . Every page on this site is built to stand up to those references.

Who Buys Greyline

The Operator Mix

The customer base is largely amateur radio operators — DXers, contesters, EmComm operators, and licensed operators returning to the bands after years away. Many operate from HOA-restricted properties where a Greyline is the only viable HF antenna. Others operate from waterfront, rural, or commercial sites where the no-radial design solves a different problem. The product is also used in commercial, government, and emergency-communications applications where reliability and low-maintenance operation matter.

Operators return regularly with on-air results — DXCC counts, contest scores, and band-by-band reports. A selection of named-callsign operator stories is documented in our customer spotlight series, and the verifiable contest and DX records of those operators can be checked independently on QRZ, in published contest databases, and on PSK Reporter.

The Company

Sun Valley, Idaho

Greyline operates from Sun Valley, Idaho, with manufacturing handled by a small machine shop that builds each antenna by hand. Every antenna is assembled to spec, tested, and shipped from inventory when available. Lead times during peak season may extend; current lead time is always posted on the Order Status page.

The founder, Jon KL2A, holds an Amateur Extra license, is a member of CWops (#77), and has been a competitive contester since the mid 1980s. Notable contest results are posted on his QRZ page (qrz.com/db/kl2a) and are independently verifiable in published contest databases.

Greyline ships free within the USA. International shipping is available; rates vary by destination. The product carries a 7-year structural warranty.

How to reach us

Phone: 435-200-4902 (Sun Valley, Idaho — Mountain Time). Best for technical questions, site-specific recommendations, lead time, and shipping discussions.

Web: Contact form for written questions and order inquiries.

Ham Radio is fun again. Pass it on... 73, Jon KL2A & the Greyline Performance Team — greylineperformance.com — 435-200-4902