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The ZS6BKW wire antenna, a variant of the G5RV, utilizes a specific 13m (42.6 ft) length of 450-ohm window line as its matching section, feeding a 28.5m (93.5 ft) flat-top element. This design aims for lower SWR on 40m, 20m, 17m, 12m, and 10m compared to a standard G5RV, often achieving SWR values below 1.5:1 on these bands without an antenna tuner. The feedpoint impedance transformation provided by the window line allows for direct connection to 50-ohm coax on multiple bands. F4FHH's experience involved constructing the ZS6BKW and evaluating its performance against an _OCF dipole_ (Off-Center Fed) on various HF frequencies. The article includes observations on SWR readings and operational effectiveness, highlighting the ZS6BKW's suitability for multi-band operation. The antenna's overall length, including the flat-top and window line, is approximately **41.5 meters** (136 feet), making it a significant wire antenna for fixed station use. Comparative analysis with the OCF dipole provided practical insights into the ZS6BKW's advantages and limitations, particularly concerning bandwidth and tuner requirements.

K6ZB Bruce presentation of technologies to allow ham radio operate via internet

1.2-30V 1.5A variable regulated power supply

This note describes a relatively small, but efficient, loop antenna initially created for portable operation. With suitable modifications, it can be adapted for fixed station use. In this age of CC&Rs, an antenna similar to this may very well be the answer to your problems. Have a look, be inspired, get out the torch / soldering iron and create your own version!

Moxons work great, and they take up less space than full size two element Yagis

The design of Ruthroff broadband voltage transformers

Firenze section of Associazione Radioamatori Italiani

A popular 2 meter antenna returns in an improved, easier to reproduce form, 2008 QST article

Homebrewed SWR meters projects by G3TXQ

Cruise Ship and Maritime Monitoring Frequencies - cruise ship frequencies maritime scanning radios vhf uhf

A half-sized Hentenna designed for unique performance in compact spaces. Initially built in 2003 for monitoring a local 146.97 MHz repeater from a basement shop, the antenna proved highly effective, operating at just 200mW. In 2005, it was adapted for use in a challenging river-bottom location, delivering reliable performance on a 2-meter band with 5W. Despite its compact size, the Forktenna demonstrated excellent results compared to a full-sized Hentenna, making it an intriguing option for many hams.

This note looks at the antenna and antenna model for the 40 meter Moxon Yagi designed by Dave Leeson, W6NL. The performance of the antenna, through the model, will be explored in several typical settings.

Designing moxon rectangles by equation and by model L. B. Cebik, W4RNL

A project for a four element cubical quad antenna for 144 MHz in portuguese

Operating a ZS6BKW antenna often involves understanding its lineage from the _G5RV_ design, with specific modifications by ZS6BKW to optimize performance on several bands. Through computational analysis and field measurements, the antenna's dimensions were refined to allow operation on 10, 12, 17, 20, and 40 meters without an antenna tuner. For 80, 30, and 15 meters, a tuner is necessary, though efficiency on 30 and 15 meters is noted as not particularly high. The physical configuration consists of two 13.755-meter radiating elements fed by a 12.20-meter section of 450-ohm ladder line. Tuning the antenna on the 20-meter band is critical, and any deviation in the ladder line's characteristic impedance necessitates recalculating the element lengths. The design is also referenced in the 12th edition of _Rothammel's Antennenbuch_, page 219. Proper common mode current suppression is crucial at the transition from ladder line to coaxial cable. This can be achieved with a common mode choke, such as several turns of coax wound into a coil or over a ferrite toroid like an Amidon T130. While a 1:1 balun is an option, it may introduce issues.

CW paddle made with a steak knife some simple hardware and a stainless steel fork

A folded wire antenna for 160 meters as appeared on 73 amateur radio magazine june 1997

Build your own multi-band mobile ham antenna with a Hamstick

G3TXQ pages focuses on understanding the HexBeam antennas. Basics, dimensions, multi band issues, antenna modeling.

ARRL comparison of HF transceivers, including Elekraft, TenTec,Icom, Yaesu and Kenwood recent transceivers based on QST product reviews

This application note is designed to help the reader understand how balun transformers can be used in today's RF/Microwave communication applications.

IC‐2300 MARS/CAP mod expanded frequency range 136‐174 MHz

This project was published in the April 2004 issue of the Australian magazine Amateur Radio, and has been designed using parts which are very readily available.

Ari Milano draw and keep updated these pdf files representing the "radioamatori" bandplan, with notes in italian

Comparison of several UHF antennas by DF9CY

J-pole designs, for 50 to 450 MHz by WA6ESC

English version of the Yaesu FT-7800 operating manual

A project for a homemade multiband Hexbeam antenna for 10, 12, 15, 17 and 20 meters

This is a 6 band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. This is a 6-band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. Stop band reject may be limited by the relay isolation. Worse case isolation is at 28 MHz or 35 dB or better. Relay K3/K8 protects the filter during transmit via the PTT line. A 25-50ms delay must be used between transmit and PTT. Do not rely on your radio to provide adequate delay with out using the PTT. You logging software must be set to allow a delay between PTT and time of 1st transmit. This filter will not work with VOX or QSK keying as you will damage the filter.

F5DQK repairing and swr measurement tests of a Cushcraft R7 Antenna

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

An antenna originally planned in the sixties, a two element beam antenna tunable on several band, in french

An easy mod to make the 1st IF of the Icom IC-7600 accessible and connect to a cheap RTL SDR dongle by VE4NSA

The HF ham bands can be mysterious. Some work at night, some during the day. Some seem to be good for long distance contacts while some are better for nearby contacts. Even worse, they change tremendously from hour to hour and day to day. An overview on operating on HF amateur radio bands

Constructing a portable, high-gain antenna for _AO-40_ satellite operations presents unique challenges, particularly regarding mechanical stability and parabolic accuracy. This resource details the build of a 1.2-meter "brolly dish" antenna, utilizing a non-conducting fiberglass umbrella frame as its foundation. The project outlines a method for achieving a parabolic shape using stressed aluminum fly screen mesh, guided by practical geometry and a temporary dowel template. Key steps include selecting an appropriate umbrella with a suitable f/D ratio (ideally >0.25), removing the original fabric, and precisely cutting and attaching eight segments of fly screen to the struts to form the reflective surface. The construction process, which took approximately five hours for the author, _G6LVB_, resulted in a dish with an f/D of 0.27 (depth=270mm, diameter=1160mm, f=310mm). The article also describes a modification to a _TransSystem AIDC_ feed, incorporating a PCB reflector behind the dipole for easier mounting. Performance tests at a squint angle of 15 deg and a range of 50,000km yielded a signal-to-noise ratio of 33dB on the S2 beacon and 23dB for SSB signals, indicating strong reception. The author notes that the modified umbrella may not close fully without risking surface disfigurement.

A Half wave antenna has a high impedance feed point. This can be matched using a 1/4 wave stub matching section and converts the 40m vertical into an L-shaped 20m J-Pole antenna. The 300 ohm feeder used for this purpose must be kept away from the ground.

Review by G3TXQ and comparison to its modificated versions. SWR Measurements on inverted V setup and comparison from EZNEC model and a real one.

German Antenna manufacturer

Amateur Radio (G3TXQ) - Malta 40 QRP CW Transceiver

Original article published on February 1992 on 73 Amateur Radio Today about the 2m and 70 cm copper cactus J-pole antenna

Chip64 mp3 file

Official Icom comparison chart for IC 756 PRO III, IC-7600, IC-7700 and IC-7800

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

The Vee Beam antenna project presents a versatile solution for hams, enabling operation across all eight High Frequency bands (80m to 10m) with significant gain on 20m to 10m. This easy-to-construct antenna utilizes two long wires at an angle, enhancing directional performance and minimizing ground losses. With a low visual profile, it is discreet and effective for various applications. The design allows for optimal leg lengths and included angles, ensuring robust performance while maintaining simplicity in construction and operation. The V Beam antenna is an aerial that you can use on all eight High Frequency amateur bands (80, 40, 30, 20, 17, 15, 12 and 10m) with an antenna tuner, and which gives significant gain on the five bands from 20 to 10 meters band.

Step by step instructions for setting up N1MM Logger to communicate with the TS-590S using the USB connection

A small antenna for limited space / lanai use.

A simple antenna tuner for 4m by Tony Hawker G4CJZ

A dipole for 2m, 4m, 6m band an hamdwritten note for a homemade vhf antenna that can be tuned across the VHF band

This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

Making your own 2 metre (146 MHz) 5/8th wave whip antenna