Search results

Adalet wireless document on antenna basics in a four pages pdf file

An easy to build antenna for ground reception of NOAA weather or amateur satellite signals. Double cross antenna by Gerald Martes

Overview, summary, tutorial about the dipole antenna or dipole aerial that is widely used on its own and as the basis for other antenna designs.

The Double Bazooka Dipole is a half wave dipole with an attempt at compensation of the reactance change that occurs around resonance for a half wave dipole.

Nagara Japanese ham radio antenna manufacturer

Notes on homebrewing antennas by Chris G4CYA, from gamma matching, to phasing antennas, splitters and combiners, baluns and measuring techniques.

Testing and comparison of traps and trap antennas

This isn’t a set of step-by-step instructions, but my info might give you some ideas for building your own antenna support.

21 mhz half wave ant -very low radiation angle - full size and light weight- all coax matching system - decoupling care to prevent low angle radiation degrade

Simple DIY stealth apartment antenna for 20m and 40m. It is basically a ZigZag quarter wave dipole antenna

A 70 cm and 2 m arrow-like antenna by DF8GH

An easy to build single wire antenna for 160 and 80 meters with a better than 2 to 1 swr across the 80 meter band by K5GP

A 40 ft vertical dipole antenna that can cover HF Bands from 80 to 10 meters winding a dipole in a 12m HD telescoping fiberglass pole

The Charles Gizmotchy high performance horizontal and vertical beam antennas. Two, Six, Ten and eleven meters antennas

This 2 meter 3 element cubical quad antenna is small, light weight and portable. A backpack antenna that is easy to put together in just minutes and parts store inside the boom making it ready for travel or storage.

The Screwdriver Antenna Memory (SAM) product is designed to enhance the mobile antenna commonly called the "Screw Driver". It replaces your current control unit and provides an automated memory feature that eliminates the visual coil tuning method commonly used.

An article on TX and RX antennae for the low bands 80 and 160m by EI7BA

An Antenna Rotator Project. The rotor design is based on sandwiching the gears and gear supports between two 5/16 inch 6061 T-6 aluminum plates

Collection of article and posts on beverage antennas

Dual Band VHF/UHF Slim Jim Antenna project

A base station antenna you can easily build for 146,220 or 440 MHz, with performance similar to a J-pole but smaller and less obstrusive

This Arduino project decode ICOM CAT frequency information and switch antennas according to preset values. RX and TX antennas can even be different, a project by ON7EQ

Members only articles on HF mobile antennas, includes an interesting RV antenna with a 5 bands coverage, and another similar antenna for camper.

A 144 MHz dipole antenna made from coax, PVC pipe, and aluminum foil tape

The page describes the construction of a simple omnidirectional, vertically-polarised dipole antenna for two metres using coaxial cable. It can be used indoors or outdoors, with no extravagant gain claims. The project is low-cost and can be completed in about 20 minutes.

Homebrew a vertical antenna for 40 and 80 meters band based on popular HF2V model by DL7JV

This is a 70cm big wheel antenna which is used at DB0FAI beacon

1/2wave vertical antenna for the 6-meterband and a 5/8 ground plane antenna for 50 Mhz

An homebrewed dipole antenna for 14MHz

W3TS small but effective antenna tuner

A vertical antenna for the top band, made with a 26m fiberglass spiderpole by DJ0IP

VE7CA experiments on 160 meters band antennas, looking for better performances on reception.

Constructing a Lindenblad antenna for 137MHz NOAA satellite reception involves specific design considerations for optimal performance. The resource details the use of 4mm galvanised steel fencing wire, 300-ohm television ribbon cable, and wood/plastic components for the antenna structure. Key dimensions for a 137.58MHz-resonant antenna are provided, derived from the ARRL Satellite Handbook, specifying s, l, w, and d as 42, 926, 893, and 654mm respectively. The antenna is designed for Right Hand Circularly Polarised (RHCP) signals, requiring the four folded dipole elements to be tilted clockwise by 30 degrees. A significant aspect covered is impedance matching between the antenna's 75-ohm impedance and a typical 50-ohm receiver input. A twelfth-wave matching transformer, constructed from 117mm sections of 50-ohm RG-58 and 75-ohm RG-59 coax with a 0.66 velocity factor, is described. The article also addresses coaxial cable and connector selection, recommending 75-ohm Type-N connectors for RG-6 cable in professional setups and F56/F59 connectors for general use, while strongly advising against PL-259/SO-259 connectors for VHF. Strategies for mitigating Radio Frequency Interference (RFI) are discussed, including antenna placement to shield from local TV transmitters and the use of commercial or DIY band-pass filters, such as cavity resonators or helical notch filters, along with ferrite chokes on coaxial cables. Antenna orientation is explored, noting the Lindenblad's 'cone of silence' directly overhead and its maximized sensitivity towards the horizon. An experimental vertical tilt of 90 degrees is presented as a method to improve overhead reception and reduce interference from strong horizontal signals, particularly relevant in high RFI environments like the Siding Spring Observatory site.

Homebrew a 2 meter 1/4 wave vertical antenna for the 146 mHz ham radio band

An homemade portable vertical antenna with a trap near the mid point of the main element. The trap is made with 42mm diameter PVC pipe with 9 turns of wire on it

Constructing a compact, two-band magnetic loop antenna for HF operation, especially from constrained locations like a balcony, presents unique challenges. OK1FOU's design, inspired by DJ3RW's 50 MHz loop, addresses these by employing an unusual side-fed configuration and placing the symmetric, two-section variable tuning capacitor at the bottom of the loop, directly connected to the coax shield. The article provides specific material recommendations, including two 1-meter wooden pales and about 3 meters of thick loudspeaker cable, noting the high current (60A at 100W) in the loop. Construction steps detail forming two turns with a 5 cm gap, using a GDO to pre-tune the open loop to a frequency slightly above the desired highest band, and then integrating the tuning and coupling capacitors. For 10/14 MHz, an open loop resonance of 16-17 MHz is suggested. Practical experience with the 10 MHz band from a third-floor balcony in Prague (JO70GC) shows a 1:1 SWR across most of the band without an external ATU. While DX traffic was modest due to the urban environment, QSO examples with RA6WF, LA6GIA, G0NXA, and LZ1QK on 10 MHz are provided, demonstrating its operational capability.

A project for a portable antenna for amateur radio satellite reception, for 2 meters and 70 centimeters bands

Crossed-Field Antennas and E/H Antennas

This halo antenna was built to have an omnidirectional coverage while working in VHF contests.

The Homebase10 is a simple to make wire halo antenna for 10m (28MHz) built using parts available from the local DIY store.The resulting antenna is very effective on 10m despite its small size and light weight.

A helix will work in the normal mode when the diameter and pitch of the helix is less than 0.1 Lambda

Don't buy or build a semi-vertical trap antenna until you read this article! If you can use a drill, saw and screwdriver this is a simple project.

A 46ft multi-band antenna for small gardens that works on 80m. An excellent DX performer and is an ideal replacement for your half size G5RV by G7FEK

A circular waveguide calculator for designing cantennas include source code and windows executable by lincomatic

A Crank up mast pipe by Bob Bruninga

The idea of using a low mount dipole, enhanced with reflector wires directly beneath the dipole, on the ground, appears to be a very good approach to creating an NVI specific antenna for local HF operation.

The W2DRZ Antenna controller system is a low cost but effective system to monitor and control an antenna system's position.

How to turn a G5RV antenna into a 160 meter band antenna with easy to find parts. A G5RV adapter for tob band by Thomas AD1B

Article by Ed Bathgate, N3SDO as published in CQ VHF Magazine July, 1988

Excel sheet containing technical comparisons of commercial HF portable antennas compiled by ON4SKY. Includes pictures, manufacturer, db gain, band coverage, F/B ratio, price, weight and dimensions.