The Grazioli Antennas MV3 is a base-fed 1/4-wave tri-band vertical ground plane antenna designed for operation on the 20, 15, and 10-meter Amateur Radio bands. Engineered to provide an excellent balance of performance, durability, and low visual impact, the MV3 is an ideal solution for operators seeking a compact multiband antenna without sacrificing efficiency. Standing 18.5 ft (5.63 m) tall and weighing just 11.0 lb (5 kg), the MV3 is lightweight yet rugged, making it suitable for a wide range of installations while typically requiring no guying under normal conditions.

Constructed from premium AW6063-T66 aluminum alloy tubing, precision CNC-machined aluminum components, and high-quality AISI 304 and AISI 316 stainless steel hardware, the MV3 is built to provide years of dependable service in demanding outdoor environments. The antenna is rated for up to 3 kW continuous power in all operating modes and includes a detailed assembly manual along with a unique serial number identifying the production batch and manufacturing data for quality traceability.

Note: For installations in areas subject to exceptionally high winds, the use of non-conductive guy ropes is recommended for additional mechanical support.

- Materials & Construction

The MV3 utilizes premium AW6063-T66 aluminum alloy tubing, selected for its excellent combination of strength, corrosion resistance, and long-term durability. Aluminum components are CNC-machined from solid stock to ensure precise fitment and superior mechanical integrity. The stub support crosspieces are manufactured from UV-resistant injection-molded thermoplastic material for long service life in outdoor environments. All mounting and fastening hardware is manufactured from AISI 304 and AISI 316 stainless steel to provide outstanding resistance to corrosion and environmental exposure.

- High-Performance Tri-Band Design

The MV3 is a resonant vertical antenna designed specifically for operation on the 20, 15, and 10-meter amateur bands. Its direct-feed design eliminates the need for impedance transformers or matching devices that could introduce losses or limit power-handling capability. By utilizing a resonant feed system, the antenna maintains efficient RF power transfer while supporting its full 3 kW continuous power rating.

The antenna incorporates a high-impedance inductive network that creates a DC-grounded condition, helping to dissipate atmospheric electrical disturbances and electrostatic charges that may accumulate on the antenna structure.

- DBFC Counterpoise System

The MV3 incorporates Grazioli's DBFC (Dual Band Folded Counterpoise) system, a unique counterpoise design that enhances operation across all supported bands while maintaining a compact installation footprint. The system utilizes four aluminum radial elements measuring 7.9 ft (2.4 m) each, along with an additional radial constructed from AISI 316 stainless steel cable.

This arrangement eliminates the need for loaded radial systems or long wire radials spread across a roof or property. The DBFC design assists with maintaining proper antenna operation even in installations located near the ground or on rooftop structures while preserving efficiency and simplifying installation.

- FAIR-RITE RF Choke System

The MV3 is supplied with an original FAIR-RITE FT240-43 ferrite toroid, manufactured in the USA, for construction of a high-performance RF choke. When installed directly below the antenna feed point, the choke significantly attenuates common-mode currents within the HF spectrum from 1.8 to 30 MHz. This helps maximize antenna performance while reducing unwanted RF current on the feed line.

- Proprietary High-Power UHF Connector

Rather than utilizing a conventional commercial SO-239 connector, the MV3 features a proprietary connector designed and manufactured by Grazioli. The connector provides a true 50-ohm characteristic impedance and is rated for operation up to 500 MHz.

The connector body is machined from nickel-plated CW614N brass, while the center pin is 24K gold-plated to resist oxidation and maintain reliable electrical contact. The PTFE insulating material provides excellent electrical and thermal performance, while a protective elastomer weather hood helps prevent moisture intrusion. The connector can handle 5kW continuous RF power at 30 MHz and more than 3kW at 50 MHz.

- Heavy-Duty Mounting System

The MV3 mounting bracket is fabricated from 0.098 in (2.5 mm) thick AISI 304 stainless steel and secures to the antenna through a robust clamping system that provides exceptional mechanical strength. Mast attachment is accomplished using an AISI 304 stainless steel M6 V-bolt and column-nut assembly, ensuring a secure installation and long-term reliability in outdoor operating environments.

Additional Features & Specifications:

- Electrical Specifications

• Type: Vertical Tri-Band 1/4-Wave Ground Plane

• Band Coverage: 20/15/10m Amateur Bands

• Feed Method: Base-Fed

• Impedance: 50-Ohm Unbalanced

• Maximum Input Power: 3,000 Watts Continuous, All Modes

• Feed System: Direct Feed Resonant Design

• Static Protection: High-Impedance Inductive Network with DC Ground

• RF Choke: Includes FAIR-RITE FT240-43 Ferrite Toroid for Construction of a Common-Mode Current Choke

• Input Connector: Proprietary UHF SO-239 Female Connector with PTFE Insulator and 24K Gold-Plated Center Pin

• Connector Frequency Rating: Up to 500 MHz

• Connector Power Rating: 5kW Continuous at 30 MHz; Greater Than 3kW at 50 MHz

- Mechanical Specifications

• Materials: AW6063-T66 Aluminum Alloy Tubing, Thermoplastic Components, Brass, and PTFE

• Hardware: AISI 304 and AISI 316 Stainless Steel Throughout

• Antenna Height: 18.5 ft. (5.63m)

• Antenna Weight: 11.0 lbs. (5kg)

• Radial System: Four Aluminum Radials

• Radial Length: 7.9 ft. (2.4m) Each

• Counterpoise System: DBFC (Dual Band Folded Counterpoise) with AISI 316 Stainless Steel Cable

• Stub Spacers: UV-Resistant Injection-Molded Thermoplastic

• Mounting Bracket Material: 0.098 in. (2.5mm) Thick AISI 304 Stainless Steel

• Mast Clamp Hardware: AISI 304 Stainless Steel M6 V-Bolt and Column Nuts

• Weather Protection: Elastomer Weather Hood on Feedpoint Connector

• Guying Requirement: Not Normally Required; Recommended Only for Installations in Extremely Windy Areas

- Additional Features

• Construction: CNC-Machined Components from Solid Stock

• Design Goal: High Performance with Low Visual Impact

• Installation Profile: Lightweight Design Suitable for Rooftop and Ground-Level Installations

• Counterpoise Technology: DBFC (Dual Band Folded Counterpoise) Eliminates the Need for Loaded Radials or Long Wire Radials

• Documentation: Detailed Assembly Manual Included

• Traceability: Unique Serial Number Identifying Production Batch and Manufacturing Data