Description
Gain-Master-2024: The Gain-Master is a high-tech 0.625λ fiberglass base station antenna covering the CB and 10m amateur bands. Completely computer designed using electromagnetic simulations to obtain maximum gain and optimize radiation pattern and band. Designed with the most advanced technologies available, it is completely built in Italy using high quality materials. The new design of the radiating element (Patent Pending) works as a dipole fed in its center, all the RF currents on the radiator are in phase so the ground plane is not necessary. The coaxial coil at the base works as an RF-choke for excellent decoupling from the support pole and the feed line. Built with telescopic fiberglass tubes, it is DC shorted for the best protection from static discharges.
Design and materials used:
Completely computer-designed with three-dimensional CAD and assembled in Italy with the best materials available, starting from the whip which is made of four 1.92m sections of telescopic composite fiberglass tubes with a triple-layer wall that makes Gain-Master™ much more resistant and rigid than competing antennas. The screws and tube fixing clamps are in AISI316 stainless steel, the aluminum tube of the bracket is in gray anodized AlMgSi AW6060 aluminum alloy. All metal components are made of CW614N alloy in the SIRIO workshops, with latest-generation numerically controlled lathes and adequately protected by galvanic treatment. The center pin of the UHF-female connector is 18kt gold plated to improve electrical contact and prevent oxidation while the insulator is made of PTFE. Gain-Master™ is the new reference standard in its class of antennas.
What technologies were used:
The low-loss coaxial cable with red sheath used to make the reel is built to SIRIO specifications by a leading Italian company and is wound on a reel support made from the best thermoplastic material available for outdoor applications: ASA.
The design and development of Gain-Master™ took almost a year and a half for electrical tests, computer simulations and choice of materials to be used.
SIRIO has carried out comparative tests with the best competing antennas on the market, with the help of the most sophisticated instruments such as:
Computerized electromagnetic simulations performed with *CST Studio Suite 2008.
Far-field Signal Analysis with the Portable Spectrum Analyzer FSL-6 from *Rohde&Schwarz®
Analysis of parameters S11 and S21, in the frequency and time domain with Vector
Network Analyzer 8753ES and E5071B by *Agilent Technologies®.
RF power tests with NRT-Z14 directional sensor (25MHz-1GHz) from *Rohde&Schwarz®.
Non-contact temperature measurements in real time with the TESTO * 880-3 infrared thermal imager .
Data collection from instrumentation and post analysis with a program developed by SIRIO in LabView®2009* by National Instruments®.
Materials and components tested at extreme temperatures with the *Votsch® VC4018 climate chamber from Vötsch Industrietechnik.
How Gain-Master™ Works in Detail:
The RF signal from the generator travels along the coaxial cable of the choke coil, then along the first part of the whip until it meets the coaxial stub that acts as an impedance matcher, then continues until it reaches the termination of the coaxial line (phase center of the antenna). At this point the part of the signal present on the central conductor passes through the capacitor and propagates along the upper half of the radiating part, while the RF currents that were traveling inside the cable shielding, flow out on the outside of the shielding and descend back towards the choke coil, where the high impedance of the coil causes them to stop (functioning equivalent to a dipole fed at its center).
Other benefits of Gain-Master™ are:
It does not require ground plane radials, as it is a balanced antenna that works as a center-fed dipole.
It is protected against static discharges so it results in DC short circuit
Thanks to its choke coil (RF-Choke) placed at the base, Gain-Master™ is perfectly decoupled from its support structure (poles, pylons, etc.) with the benefit of maintaining both the impedance and the radiation pattern unchanged.
It has an exceptionally wide bandwidth of over 4.5MHz (400CH) from 25.5 to 30MHz and requires no calibration throughout the declared band.
It accepts a maximum continuous power of 500 Watts RMS.
Gain-Master™ features the highest gain achievable for a 5/8λ antenna and thanks to its perfectly horizontal radiation angle it allows to improve the performance compared to the best competing antennas by at least 1-2dB which corresponds to 26% – 58% more signal as it is evident from the comparison of the diagrams and from the far field tests with a spectrum analyzer.
Specifications:
2024 Upgrade: New plastic reinforcement sleeve
Pole fixing bracket: Max diameter increased to 60mm
Type: 0.625 λ center feeded vertical dipole
Frequency range: 25.5 – 30 MHz 400 CB channel & 10m ham band
Systems: 10m-HAM
Gain: 1 to 2 dB higher than conventional 5/8 λ
Max Power: 500 Watts (CW) continuous
Radiation: Omnidirectional
Polarization: Linear vertical
Grounding protection: DC-Ground
Connector: UHF-female (SO-239)
Materials: Anodized Aluminum, Copper, Stainless steel, Fiberglass, Thermoplastic UV stabilized
Height (approx): 7360 mm / 24.15 ft
Weight (approx): 3000 gr / 6.61 lb
Mounting type: On-Mast / Mounting mast Ø 35-60 mm side mast with “V” bolt
Impedance: 50 Ohms
Wind Resistance: Up to 160 Km/h using bracing rods
Lighting protection: All metal parts are DC-grounded, the inner conductor shows a DC-short
Max Gain on the horizon: 1 to 2 dB higher than conventional 5/8 λ
12m Band: Covered band with manual or automatic tuner.
