HF SCADA Telemetry Antennas | 3–30 MHz Remote Site Structures for Utilities and Agencies
Agency & Industrial · HF SCADA
HF SCADA Telemetry Antennas: One Rated Structure for Remote Sites, No Radials, No Tower
An HF SCADA system uses the 3 to 30 MHz spectrum to carry telemetry and supervisory control between a master station and remote sites — pump stations, well fields, substations, valves, reservoirs, gates — where there is no fiber, no cellular, and no line of sight for VHF. The radio is the easy part. The antenna at the remote site is what fails, gets vandalized, cannot be approved, or needs a crew to service. This page is about that antenna.
Greyline vertical dipoles are in service at state emergency operations centers, US Embassies, and defense contractor sites, and they carry MARS and emergency traffic every day. The same structure that flies a flag in an HOA is the one that goes on a concrete pad at a remote site: 160 through 6 meters from one feedpoint, no buried radial field, ASCE 7-10 wind-rated, one person to raise or lower it, made in the USA.
Section 889 compliant · COTS procurement · 7-year guarantee · Capabilities statement and procurement justification brief below
Why HF for SCADA, and What the Antenna Has to Do
HF reaches where nothing else does. On the lower frequencies a signal refracts off the ionosphere and returns within a few hundred miles — near-vertical-incidence skywave, NVIS — which covers a county or a service district with no repeater and no tower. Higher in the band, the same antenna carries a link across a state. A SCADA polling cycle needs only a few hundred bits per site, so a modest HF radio and a rated antenna do the work that a microwave backhaul or a cellular contract does elsewhere, at a fraction of the recurring cost and with no third party in the path.
The antenna therefore has four jobs: cover the frequencies the license allows, whatever they are; survive the site's wind and ice without a maintenance visit; go in on the ground that is there, which is usually concrete, gravel, or rock; and be serviceable by one technician with no bucket truck. Every one of those is a design requirement we have been building to for a decade in residential and agency installations.
What a Greyline Vertical Dipole Brings to a Remote Site
Every licensed HF frequency from one feedpoint. The antenna is a non-resonant off-center-fed vertical dipole. With a wide-range automatic tuner at the base it covers 1.8 to 54 MHz continuously — so a frequency change on the license is a tuner setting, not a new antenna.
NVIS and long-haul from the same pole. Regional NVIS traffic and longer skywave paths both work on this design, and the operators who pass emergency traffic on it are the proof. One antenna per site covers the district and the state.
No radial field. A conventional vertical wants dozens of buried wires to work, and a remote pad is not where you bury them. The vertical dipole returns current through its own lower element, not the ground, so it goes on concrete, asphalt, gravel, rock, a rooftop, or a frozen site with the same result. The physics is Rudy Severns, N6LF's, on ground loss under verticals; the design is ours.
Rated, not guessed. Every height carries an ASCE 7-10 wind rating — 155 mph at 12 feet down to 55 mph at 28 feet — from actual geometry and the published methodology. Heavy-wall 6061-T6 aluminum, stainless hardware, fiberglass insulators. Ask an antenna vendor which standard produced their number; if they cannot name one, that is your answer.
One technician. On a Tilt-Up Base the whole antenna comes to waist height with four bolts and one person. Tuner service, inspection, storm prep, and a return to vertical without a lift or a second truck. That is the difference between a site visit and a work order.
Low profile where it matters. A two-inch pole reads as a flagpole or a light standard. At sites with neighbors, or sites where an antenna invites attention, that is a security feature.
Choosing the Height
Height is aperture, and aperture pays most on the lowest frequencies on the license. Every height from 12 to 28 feet covers the full range; the taller antennas are more efficient on the low end and the shorter ones carry the higher wind ratings an exposed site wants. The 9-foot whip adds aperture to any height and comes off in two minutes when weather is forecast. Bring the frequencies on the license and the site's wind exposure to the Selection Guide, or to us, and the height follows from those two facts.
Multiple sites are specified as a system: the same antenna, tuner, tilt base, and coax at every remote, so a technician carries one set of spares and one procedure. We quote by site count; ask.
The Complete Remote-Site Package
Antenna · remote automatic tuner at the feedpoint, powered over the coax · Tilt-Up Base or no-dig concrete mount · genuine LMR-400 or Heliax, cut to length and sealed · 316 marine hardware for coastal or corrosive sites. One purchase order, one vendor, one point of contact.
For Procurement
Capabilities Statement · Procurement Justification Brief · EmComm & HF Hardening · Agency & Government Solutions
Section 889 compliant. COTS. Made in the USA. Quotes by site count; net terms for agencies on request. Larger structures for master stations — including 80-foot galvanized monopoles, in stock — are on the Commercial Offerings page.
Talk to an operator, not a sales desk: 435-200-4902, or CQ@greylineperformance.com. Bring the frequencies on the license, the site count, and the wind exposure; that is enough to spec the system.
Greyline Performance — Sun Valley, Idaho
Made in the USA