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The G5RV antenna, with an overall length of **31.10m (102ft)**, functions as a 3/2-wave on 20 meters when installed horizontally at 12m (39ft), exhibiting a resonant frequency of 14.150MHz and an approximate resistance of 80 ohms. Its 10.36m (34ft) stub line, designed as a 1/2-wave on 14.150MHz with a 0.97 velocity coefficient, acts as an impedance transformer across other bands, aiming for multiband operation without traps. On 20m and higher frequencies, the G5RV demonstrates improved gain compared to a standard dipole, attributed to the _collinear effect_ from multiple 1/2-waves along the wire. The original design sought a multiband solution for limited spaces, often requiring an Antenna Tuning Unit (ATU) for effective operation across bands like 80, 40, 30, and 20m, particularly with modern solid-state PAs. Variants, such as the F8CI modification, incorporate a 1/4 current balun at the stub line's base for symmetrical-to-asymmetrical transition, known as a _remote balun_. Proper flat-top or inverted-V installation is critical for maintaining symmetry and collinear gain, with inverted-V apex angles below 120° progressively diminishing higher-band performance.

DJ9RB details several antenna projects, including loaded dipoles and verticals specifically for the 160m, 80m, and 40m amateur radio bands. Featured designs include a 160m loaded dipole with end capacitance, a 160m loaded L-antenna, and a 160m kite-supported vertical. For 80m, the resource describes a short broadband dipole (80BBDP), an 8m high top-loaded vertical (TLV80) with elevated radials, and a shielded loop for 3.5 MHz. For the 40m band, a 7m high top-loaded vertical (TLV40) and a 6m high portable top-loaded GP (TLV40mesh) are presented, both optimized for 7 MHz. Additional dipole designs cover 40m, 30m, 20m, 17m, and 6m bands, utilizing coaxial cable traps. The page also mentions specific vertical antenna variants like the TLV20 (GP14MHz) with two radials and the TLV30HWL-10MHz, a loaded half-wavelength vertical. The content includes information on high-power homemade components, such as a 3.5 MHz AM transmitter from 1964 and a 14 MHz portable transceiver from 1977. It also touches upon measurement instruments, BNC connector assembly, and QTH details from DJ9RB's operations, including H44/DJ9RB from the Solomon Islands.

A 3 band dipole antenna for 40-80-160 meter bands, It's made with easily available materials and is designed for inverted V mounting. The antenna is shortened for these bands, but still manages to make contacts in 80m and 160m with stations in Canada and the USA. The construction details are provided, including the dimensions of the antenna elements and the traps. The antenna is easy to build and provides good performance in all three bands. In Italian.

Make your own dipole for 40 and 80 meters band, assembling standard product parts like 40 meter traps, the 1:1 balun and insulators

A Trapped dipole inverted V antenna for lower HF Bands. Construction details are for temporary installation. Permanent installations will require additional ruggedising and waterproofing however the basic electronics concepts remain the same. This project includes SWR plots for the three bands and pictures details of the homemade traps.

Learn how an experienced ham radio operator rebuilt his trap dipole antenna for 30, 40, and 80 meters after a storm damage. Discover the process of upgrading to a short trap dipole for 40, 80, and 160 meters using double-wound traps made from RG-58 coax. Follow along for construction details and tips on building this unique classi.