Model ST-230
HF Transportable Tactical Spiral Antenna 2-30 MHz Dual

Frequency Range: 2-30 MHz
VSWR: 2.0:1 max
Polarization: Horizontal and Vertical
Size: 40′ H

 View Product Specs PDF   |   Request Quote

Not finding what you’re looking for? We can custom-build antennas to your exact specifications.
Contact us here or call 1-940-325-3301 for more information.




The ST-230 is a transportable antenna that can be quickly erected and is suited for both horizontal and vertical polarization for short range communications. The antenna has two modes of operation, the modes may be used independently and simultaneously.


Designed for rapid deployment and utilizing a lightweight telescoping mast, it is possible for two men to erect the antenna in 30 minutes. The ST-230 spiral design utilizes the 40 feet extended height to support the pyramidal configuration.


The even mode of operation provides predominantly vertical polarization at elevation angles suited for medium or long range communications using the skywave propagation and very short ranges using surface-wave propagation. The odd mode of operation utilizes predominately horizontal polarization at high angles of incidence for short range communications. The antenna is fed by a hybrid which has two 50 ohm input terminals. The mode of operation depends on which input is used. Both modes may be used simultaneously. Eight 40 feet long radial wires form a ground system and locates the anchors.

Equipment Supplied:

Equipment supplied includes the telescoping mast, element wires, hybrid, terminations, accessory kit and canvas carrying bag.

Optional Equipment:

Transit case.

Spec Sheet


Input Connector Type N
Gain, Odd Mode, 2 MHz -12 dBi
Gain, Even Mode, 2 MHz -16 dBi
Weight, STU-3HD 17″ L x 19″ H x 17″ W
Gain, Odd Mode, 30 MHz -2 dBi
VSWR 2.0:1: Max Across the Band
Weight 200 LBS
Frequency Range, Even Mode 2-30 MHz
Frequency Range, Odd Mode 2-30 MHz
Erection Time, 2 Men 30 Minutes
Dimensions, Erected, Height 40 Feet
input Impedance 50 Ohms Unbalanced
Power Capability 500 Watt avg / PEP
Dimensions, Erected, Base 57 x 57 Feet Sqaure
Gain, Even Mode, 30 MHz -6 dBi
Wind Loading 67 mph
Polarization, Odd Mode Predominately Horizontal
Polarization, Even Mode Predominately Vertical