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Drawing and plan for an HF magnetic loop antenna

HB9MTN Capacitive antennas for 40m, 30m AND 20m

Building a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.

An homemade portable trapped dipole antenna for 40 and 80 meters band with an optional extension for the 20 meters.

Notes on W3EDP Antenna by M1KTA

An easy portable VHF antenna to build for ARES - RACES work is the 300 Ohm Twin Lead JPole antenna

A 70cm and 2m 6 elements yagi antenna plan based on the IEEE Transactions on Antennas and Propagation

Ferrite rod antenna or aerial, a form of RF antenna that is widely used in RFID and transistor radio applications.

Basic of shortwave antennas

This is the Loop Antenna Group to Ask Your Questions, Get Answers and Information about Loop Antennas for improved your Radio Listening and Enjoyment.

Comparison of 50 and 70 Mhz antennas, commercial and home made projects

Issue 35, October 1992 Six News

A very basic guide to antennas concept. Explain the usage of dummy load, basic antennas like dipole o j-poles.

2 Meter Indoor Slim Jim Antennas for Cyclone Season and Other Uses by VK4MDX

A Useful Horizontally Polarised Omni-directional Antenna with Gain for 144 MHz

The basics of what is a discone antenna for wide band or bandwidth omnidirectional applications.

Analysis of an antenna trap where a coil is formed of a length of coax cable, the outer conductor of one coax end is tied to the inner conductor of the other coax end, and the remaining connections form the terminals for the trap.

ARRL article on random wire antenna, simple antennas that can be tuned for every band, excellent solution for field day operations

W3EDP antenna assembly instructions and dimensions with pictures in this PDF File

Homebrew a 2 meter square dipole antenna

Here we have a ground plane antenna mostly used for 144, 222, 440 Mhz. Its one of the simplest antennas to make. New hams can build this with little to no experience in antenna building.

An off centre fed dipole, with 10 feet of vertical radiator. It needs no tuner on 40m, 20m and 10m by M0UKD

All types of Military Antennas, Law Enforcement Antennas, Mobile Radio Antennas, GPS Antennas, Satellite Antennas, WLAN/Wi-Fi/WiMax Antennas, Cell Phones, TV, HDTV Antennas available and sold

A project of a 5 Antennas Relay Switch Box, all Switches & Relays have both contacts wired in parallel to improve reliability of operation, to prevent static build up, when an antenna is not in use the feeder coax is grounded.

17-Element Very High Frequency/Ultra High Frequency Log Period Dipole Array

Deploying robust antenna infrastructure for both fixed and portable operations often requires specialized support structures capable of withstanding environmental stresses while providing optimal radiating element placement. SMC offers a range of solutions, including pneumatic masts and push-up masts, designed to facilitate rapid deployment and reliable long-term support for various antenna types. Their product line encompasses antenna mounts, poles, and complete antenna systems, addressing the critical need for stable and efficient RF communication. The company's offerings extend to HF antennas, including dipoles and _NVIS_ (Near Vertical Incidence Skywave) antennas, which are crucial for short-range regional communications on bands like 80m and 40m. These systems are engineered for durability and performance, ensuring signal integrity across diverse operating conditions. With over **65 years** of experience, SMC has established itself as a global manufacturer in this niche. Their product portfolio also includes antenna support towers, catering to more permanent installations requiring significant height and load capacity for multiple arrays.

G3TXQ study on coaxial cable demonstrate that it can reduce an element's length by something approaching the Velocity Factor of the cable

A simple coax dipole antenna for 144 MHz by 9A7PJT

Iulian Rosu YO3DAC / VA3IUL wire ham radio antenna panoramic with sample drawings

An RSGB article on end-fed wire antennas and the W3EDP alternative.

The rhombic antenna is often claimed to be an exceptionally good antenna with very high gain. Modelling rhombic antennas

Raising large Yagi antennas can be a challenging project. A trolley system will make the job a lot easier

A complete guide to magnetic loop antenna construction, with analysis of multi-turn and single-turn magneti loops, and and insight on choosing the optimal capacitor, or homebrewing your own butterfly capacitor

A switchable Magnetic Transformer for Transmitting for various impedances

The antenna is a VHF side is a 2m moxon, tuned on 145.825 MHz. The driven element of the moxon couples to a driven element for a 5 element 70cms Yagi, tuned on 436.5 MHz.

Experiments with spiral dipole antennas. Includes two spiral antenna designs for 20 and 40 meters band by KN9B

This modification will allow the use of separate receive and transmit antennas on the Kenwood TS-850S/AT.

Experiments on HF antennas for restricted spaces. In this article author experiments antennas for 80-10 meters band having just a very small garden and several restrictions. Basic antennas consists of laded multiband dipoles and fan dipole antennas

Comprehensive information page about bi-directional Beverages, including applications, construction details, and tips.

VE3CVG 222 MHz (1.25m) 6 element plumber's delight yagi antenna

Understanding Amateur Radio NVIS Antennas and Propagation

The design and feeding of driven elements for VHF/UHF Yagi antennas , modeling, observations and some case studies by Graham Daubney F/G8MBI

Green that aluminum into something useful right in your own backyard by WB2CQM

A fractional bandwidth of up to 30:1 characterizes spiral antennas, making them highly effective across a very wide frequency range, often from 1 GHz to 30 GHz. The resource details two primary types: the **Log-Periodic Spiral Antenna** and the **Archimedean Spiral Antenna**, defining each with specific polar functions and illustrating their planar configurations. It explains that spiral antennas are typically circularly polarized, with a Half-Power Beamwidth (HPBW) of approximately 70-90 degrees, and a peak radiation direction perpendicular to the spiral plane. The content elaborates on critical design parameters affecting radiation, including the total length (outer radius) for lowest frequency, the flare rate ('a' constant) for optimal radiation versus capacitive behavior, the feed structure (often an infinite balun) for high-frequency operation, and the number of turns (typically 1.5 to 3 turns). It also discusses the theoretical impedance of 188 Ohms for Log-Periodic spirals, derived from Babinet's Principle, noting actual impedances are often 100-150 Ohms. The article presents a simple construction method for an Archimedean spiral, demonstrating VSWR and efficiency measurements. Measurements from a constructed spiral antenna show a VSWR that is fairly constant across the band, albeit with a mismatch loss of about 3 dB. The antenna efficiency remains around -5 dB (31.6%) across its operating range, indicating a decent wideband radiator despite opportunities for optimization.

This page allows you to calculate in the most accurate way high-Q inductor coils.

The Gizmotchy high performance horizontal and vertical beam antenna for 2/6/10/11 meter bands

A page by 9A7PJT dedicated to HB9CV yagi antennas includes link to the HB9CV calculator program and some interesting plans

Measurements for building a full wave loop using wire

The essentials of the parabolic reflector or dish antenna and its theory and design for high performance applications such as satellite transmission and reception as well as microwave links.

Antennas for restricted lots, apartments and indoor antennas by VK3YE