Description
HW20V: Grazioli Antenna is an Italian company specializing in the design and manufacture of antennas for amateur and ham radio. Founded in 2016, the brand has quickly established itself thanks to a combination of quality and performance. The range of antennas is designed to meet the needs and expectations of the most demanding radio enthusiasts who are looking for robust, durable and easy to install antennas. The founder, Pier Francesco Grazioli, is the son of the founder of the SIRIO brand. He has more than 30 years of experience in the development of antenna products and is passionate about his work. Grazioli manufactures 100% in Italy, using the best materials and technologies available, as well as highly qualified component suppliers. His commitment to excellence is reflected in all Grazioli Antenna products.
Technical choices that make the difference:
Why build an antenna capable of withstanding 3 kW of continuous power?
Because an antenna that accepts high power is a more efficient antenna. Otherwise, it would tend to heat up due to the Joule effect and dissipate a significant part of the applied RF power as heat, something that happens with most competing products but which, unfortunately, users cannot test for want of adequate equipment and instrumentation.
High-“Q” LC matching circuit:
For this product, we have made a special parallel LC circuit to adapt the high impedance presented by this type of antenna when it is fed at the base. The high-Q coil is generously sized, suspended in air, with widely spaced coils and no metal cores. The coaxial variable capacitor (similar to a Gamma Match) is located at the base next to the coil for easy tuning. Made with PTFE insulation, it can withstand extremely high voltages exceeding 40kV, and It is insensitive to ambient temperature, rain and humidity and does not heat up when subjected to high power.
During the development of the matching circuit, we had to carefully adjust both the inductance (L) and the capacitance (C) to obtain a truly efficient circuit that is reliable and trouble-free. All this results in high efficiency and the ability to handle RF power up to 3 kW continuous all-mode. In addition, the coil is directly DC-grounded to significantly reduce atmospheric noise.
Materials & Construction:
For our tubes, we have used the best antenna construction alloy available: AW6063-T66 is an alloy of Aluminum, Magnesium and Silicon that is hardened to a T-66 temper which gives the stylus exceptional resistance. It is shaped by extrusion and subsequent cold drawing. Our tubes are extremely accurate on both diameters and also on the wall thickness, ensuring a precise fit with less ‘play’ between the tubes.
UHF Connector:
The antenna connector is not the commercial SO-239 type used by most manufacturers. Our connector is designed and built directly by ourselves; it has a true 50 Ohm characteristic impedance and is rated up to 500 MHz. We have created a reliable connector capable of withstanding 5 kW of continuous RF power at 30 MHz and greater than 3 kW at 50 MHz. The body is made of CW614N nickel-plated brass, while the pin is plated in 24K gold to avoid oxidation and is equipped with a 4-fin insulator that maintains its centering and elasticity to avoiding contact losses. The insulating material is PTFE, one of the best insulators due to its exceptional electrical and thermal properties (low dielectric constant and reduced loss factor, operating temperature from -100 to +260 °C). The assembly is protected by a special elastomer hood that prevents water and humidity infiltration.
The Anchor Bracket:
Is made of 2.5 mm-thick AISI 304 stainless steel and is attached to the antenna tube by means of a clamping system, creating an extremely robust mechanical lock. The mast coupler is consists of an M6 V-Bolt in AISI 304 steel and column nuts for easy, secure tightening.
Features:
Vertical 1/2 λ antenna fed at the base for the 20m band by fine tuning through PTFE-insulated high-voltage variable capacitor.
Extremely robust construction in AW6063-T66 aluminum alloy and CNC machined parts from solid stock.
Supplied with high-quality 304 and 316 stainless steel fasteners for long rust-free operating life.
High input power, up to 3 kW continuous all-mode.
Detailed assembly manual and serial number that identifies the production batch and construction data.
Specifications:
Frequency range: 20m band – Full coverage
Type: 1/2 λ vertical dipole powered at the base
Impedance: 50Ω unbalanced
Radiation: omnidirectional
Bandwidth: @SWR 2:1 ≥ 0,8MHz
Polarization: vertical – linear
Gain: 0 dBd (2.15 dBi)
SWR at resonance: ≤1.2:1 Typical ≤1.1:1
Maximum applicable power: 3000 Watts continuous all transmit modes
Power System: High “Q” LC circuit – DC grounded
Connector: UHF female (SO-239) with PTFE insulation, gold-plated centre pin
Materials: AW6063-T66 aluminum alloy cold drawn tube, fiberglass, brass, PTFE, all screws are AISI-304 and 316 stainless steel
Wind surface: 0.265m2
Wind resistance: 130 Km/h (guyed)
Total height: 10.13m (half-wave)
Mast mounting: ø 40-54 mm
Net weight : 5,4 Kg
Package dimensions: 14 x 14 x 145 cm
