- A Little Antenna Theory
- RFI BA80-67
- RFI OA20-41 VHF Antenna
- Diamond X6000A Triband Base Antenna
- Diamond VX1000 50/144/430mhz VHF UHF 6m 2m 70cm
- Diamond D-130J Super Discone Antenna
- The Southern Cross Tower with Antennas Layout
A Little Antenna Theory
Horizontal Dipole (Eg Horizontal Yagi):
Diagram showing the relationship between the E and H planes for a horizontally polarized directional yagi antenna.
In this case E-Plane is Horizontal and the H-Plane is Vertical.
Vertical Dipole (Eg Vertical Pole):
Diagram showing the relationship between the E and H planes for a vertically
polarized omnidirectional dipole antenna.
In this case E-Plane is Vertical and the H-Plane is Horizontal.
Some pratical Notes:
- Mounting an antenna less than half a wavelength from a tower will alter the pattern.
- The objective is to direct the highest gain to the most used area of service.
- On the BA80-67 there is a lose of gain of approximately 7 db in the least favoured direction.
UHF Omnidirectional Dipole Arrays330-520 MHzBinary Array Series
The BA80-67 arrays utilise an internal phasing harness in PTFE based double
screened coaxial cable with polyethylene jacket to aid waterproofing and
resist bird attack. The use of a unique phasing arrangement provides extensive
side lobe suppression and null fill characteristics. The arrays will accept
an input power level of 500 watts continuous, making them ideal for high power
multiple transmitter applications. The BA80 series are offered with 3°, 5° or
8° downtilt, to further enhance close-in coverage characteristics.
All welded alodined aluminium construction and new fabrication techniques in
both the harness and dipole sections have proven to minimise intermodulation
and noise generated within the antennas. The entire array rests at ground
potential and offers the ultimate in lightning resistant antennas.
- Ideal for highly populated sites requiring long haul omnidirectional coverage
- Operate over entire 330-420 or 400-520 MHz bands
- Continuous power rating of 500 watts
- 3, 6 or 9 dBd gain versions available
- Inverted mounting version available
- Versions with 0°, 3°, 5° or 8° of downtilt available
- Extensive side lobe suppression and null fill
- Industry leading PIM ratings (-150dBc) providing low IM and
low noise characteristics for optimum performance
What is the purpose of alodine?
It is primarily used as a corrosion inhibitor, primer, decorative finish,
or to retain electrical conductivity. The process is named after the chromate
found in chromic acid, also known as hexavalent chromium, the chemical most
widely used in the immersion bath process whereby the coating is applied.
RFI OA20-41 VHF Antenna
VHF Offset Dipole Arrays 136-174 MHz OFFSET ARRAY SERIES
- Nominal Gain: 5dBd
- Frequency: 136MHz to 174MHz (Center 155MHz)
- Tunable Bandwidth: Full and No tuning required
- VSWR: less than 1.5:1
- Polarisation Vertical
- Vertical Beamwidth: 35°
- Horizontal Beamwidth: 178°
- Power: 750W
- Passive IM 3rd Order (2x20W) dBc: less than -150
- Construction: All welded aluminium with alodined finish.
- Length : 3500mm
- Weight : 12.5kg
- Termination: N female with 0.5m 9142 cable tail.
- Mounting Area: 500mm x 63mm diam. aluminium
Diamond X6000A Triband Base Antenna
- Fiberglass radomes
- Overlapping outer shells for added strength
- Strong waterproof joint couplings
- Stainless steel hardware
- Wide band performance
- Factory adjusted – no tuning required
- High wind rating
- DC grounded
- Band: 2m/70cm/23cm
- Gain (dB): 6.5/9/10
- Max Power Rating: 100/60
- Wind Rating: 112 MPH (no ice)
- Height (feet): 10.5
- Connector: Type-N
- Element Phasing: 2-5/8l, 5-5/8l, 6-5/8l
x6000's 145MHz radiation pattern:
x6000's 145MHz radiation pattern:
x6000's 1280Mhz radiation pattern:
Diamond VX1000 50/144/430mhz VHF UHF 6m 2m 70cm
Diamond VX1000 50/144/430MHz(6m/2m/70cm) is made of fibre glass construction,
pre-tuned and fully weatherproofed. No radials are required. Mast mounting
brackets are included.
- Max. power rating:150W SSB(Total)
- Impedance:50ohms VSWR:Less than 1.5:1
- Rated wind velocity:60m/sec.
- Mast diameter accepted:30mm to 62mm
- Type: 1/2wave (50.5-52MHz), 1/2wave radialless (144MHz), 2 x 5/8 wave radialless (430MHz)
- FRP outershell
Diamond D-130J Super Discone Antenna
The D-130J Super Discone Antenna is an ultra-wideband antenna covering amateur
radio, commercial 2-way, cellular, air traffic control and various utility
frequency bands. Rust-free stainless steel is employed in major component
parts making the antenna rust resistant and durable.
- Ultra-wideband design 25 to 1300 MHz receive, 50-1300 MHz transmit (6m tunable for transmit)
- Compact and lightweight design enables antenna to be installed on balcony railing at an apartment or condominium
- Ideal for 2m, 1-1/4m, 70cm, 33cm and 23cm amateur bands
- Excellent "shop" antenna for testing various transmitters on a single coax
- Can be made further compact and lightweight by removing the top loading coil if 25-50 MHz reception is not required
- Bands: 25-1300 MHz
- Gain dBi: 2 (nominal)
- Max Power Rating: 144 MHz up: 200 watts
- 6m: 20 watts FM, 50 watts PEP
- Height: 5.6'
- Weight: 2.2 Lbs.
- Connector: UHF
- Element Phasing:Wideband Discone
A discone antenna is a version of a biconical antenna in which one of the cones
is replaced by a disc. It is usually mounted vertically, with the disc at the
top and the cone beneath. Omnidirectional, vertically polarized and with gain
similar to a dipole, it is exceptionally wideband, offering a frequency
range ratio of up to approximately 10:1. The radiation pattern in the vertical
plane is quite narrow, making its sensitivity highest in the direction of the
horizon and rather less for signals coming from relatively close by.
The Discone Assembly Instructions:
The Southern Cross Tower with Antennas Layout
Diamond Antenna Product Catalogue:
Notes on HF Discone Antennas L. B. Cebik, W4RNL
Discone Antenna Design - Written by Bill Pretty Highpoint Security Technologies
All About the Discone Antenna: Antenna of Mysterious Origin and Superb BroadbandPerformanceSteve Stearns, K6OIK
Glenn Lyons VK4PK
Ver:gnl20190328 - pre published v0.9