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This page describes a simple way to determine the main RF characteristics of a Wifi (IEEE802.11b/g wireless LAN) antenna.

ARRL index of document about trapped antennas and notes on traps usage

modifications collected about Yaesu VX-150 by mods.dk

Article on rhombic antennas, radiaton patterns, disvantages, and more info on rhombic aerials

Rigpix database large picture of the Yaesu FT-897

If your IC-706MKIIG will not power up without even hearing a relay click, check the state of the HV line.

Displays map of the world, showing day and night areas.

This doubet antenna is a half wave dipole antenna easy to build, in french

AirMail is a HF radio mail program for sending and receiving messages via Pactor, either via the ham radio system or participating marine or commercial services

LOGvrr, a **freeware logging software** developed by IN3VRR, provides amateur radio operators with essential tools for managing their contacts. The resource details various downloadable components, including the core LOGvrr application, an international callbook with approximately 1.8 million callsigns, and utility programs for installation and data conversion. It supports functionalities like logging QSOs, managing awards, and interfacing with PacketCluster systems, with specific instructions for installation on Windows operating systems, including compatibility notes for Windows 10 and 11 using Hyper-V or DOSBOX. The site also offers external tools and documentation, such as the FAQ_VRR.PDF manual which covers installation, printer configuration, ADIF conversion, and Packet setup. It references third-party software like Mercurio and BV QSL Management for QSL printing, and ADIF2QSL for label printing, highlighting LOGvrr's ability to export QSOs in **ADIF format** for integration with services like LoTW. The resource includes historical updates, with the latest core component update in August 2014, and notes on the CallBook's maintenance up to 2015.

German article on the multiband dipole by DG0KW. This antenna can be configured for several bands and can work in 3 or 4 bands mode. Can be used in restricted space lots.

The program calculates the actual position of the satellites using the NORAD 2LINE-element set, which is available via the Internet, for nearly all satellites. The position is then displayed in 3D-view as well as in 2D (mercator) view, where the footprints are also be shown.

A vertical antenna for 40 and 80 meters band with no need of antenna tuner, based on a telescopic fiberglass mast of 48 feet by N8NSN

Various radio related software, including some antenna analysis, and impedance calculators.

Free Donwload of the PDF file of ITU and CQ zones of the world, made available by Icom America

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

Presented here is a high-performance, circularly polarized omni-directional antenna that is easy to build, easy to tune, inexpensive, and will work all the mode J Low Earth Orbit (LEO) satellites

FT857 Programming Software works with FT817 FT897 too. Demo version available.

Experiments with phased wire vertical antennas on 40 meters at VA7ST

JJ0DRC's HF multi-band delta loop antenna project, initially conceived during the waning peak of Cycle 23, addresses the common challenge of achieving effective DX operation from a small residential lot in Japan. Dissatisfied with a ground plane antenna's performance in SSB pile-ups, the author sought a beam-like solution without a tower, drawing inspiration from a JJ1VKL article in CQ Ham Radio Sep. 2000. The antenna, constructed in October 2000, employs two 7.2-meter fishing rods (37% carbon fiber, reinforced with cyano-acrylate glue and aluminum tape) and 1mm enameled wire, fed by an Icom AH-4 external antenna tuner. While the exact beam pattern remains unmeasured, JJ0DRC observed a significantly higher callback rate compared to dipole antennas, particularly on higher bands. The system's circumference length of 15-20m is crucial for maintaining a good beam pattern across HF bands, though performance on lower bands like 80m, 40m, and 30m becomes less directional as the length deviates from a full wavelength. Ongoing maintenance addressed degradation issues, including aluminum tape cracking and wire breakage at connection points due to strong winds (often exceeding 10-15m/s in winter). The author reinforced rod connections with IRECTOR PIPE SYSTEM components and INSU-ROCK ties, and improved wire attachment methods using Cremona rope and epoxy bond to enhance durability.

This resource details the computer-optimized design of the _ZS6BKW_ multiband dipole, an evolution of the classic _G5RV_ antenna. It begins by referencing the original 1958 RSGB Bulletin article by Louis Varney G5RV, explaining the operational principles of the G5RV's flat-top and open-wire feedline on 20m and 40m, noting its impedance transformation characteristics for valve amplifiers of that era. The article then transitions to the rationale for optimizing the design for contemporary solid-state transceivers requiring a 50 Ohm match. The core of the project involves using computer modeling to determine optimal lengths for the flat-top and matching section, aiming for a VSWR of less than 2:1 on multiple HF bands. It discusses the process of calculating feedpoint impedance based on antenna length and frequency, referencing professional literature from Professor R.W.P. King at Harvard University. The analysis also considers the characteristic impedance (Z(O)) of the open-wire line, identifying a broad peak of adequate values between 275 and 400 Ohms. Specific design parameters for the improved ZS6BKW are presented, including a shorter flat-top and a longer matching section compared to the original G5RV, with a velocity factor of 0.85 for the 300 Ohm tape. The article confirms acceptable matches on 7, 14, 18, 24, and 28 MHz bands when erected horizontally at 13m, and also discusses performance in an inverted-V configuration, noting frequency shifts. The author, Brian Austin ZS6BKW, emphasizes the antenna's suitability for modern 50 Ohm coaxial cable without a balun.

A simple base loaded quarter wave vertical, which can be used on a car or portable by G3YCC

ShipPlotter displays complete information about ships that are within VHF range of your position using the Universal Automatic Identification System (AIS).

Using the FT-857 Microphone Jack for Serial Control (CAT)

Dedicated ham radio internet gateway and server system. It is intended for use by RF gateways and PC users connected to the internet

Based on the N2PK design, this swr meter use a stockton directional coupler

Built around a 1/2" pvc frame, Larry's 6 meter moxon antenna is made from #8 aluminum ground wire

Shareware program to receive and transmit high speed CW (morse code) used in MS (amateur radio communication mode) with MS Windows 95/98 and sound card.

US Amateur Radio Band Plans by ARRL

Double bazooka antennas

This antenna was designed to meet the requirements of a light body worn small magnetic loop covering all the frequencies continuously from 7 MHz to 29.4 MHz

"A collection of nearly all facts around the YAESU Musen products; products, company history and much more"

This is a simple calculator for solving the antenna wire catenary between to end points given the design wind speed, mass per unit length of the wire, wire diameter and Gross Breaking Strength of the wire.

How to make easily your N-type connector, pictures and procedure, step by step

Design for a 5 element beam on a 23 foot boom with an unusual combination of performance characteristics

HF pedestrian operation using loop antennas by PY1AHD

Amateur Radio, Citizen's Band Radio, Commercial Radio, General Electronic items, Marine Radio, and Short Wave Radios, Hamilton Ohio

SSTV Fundamentals, frequencies in use for SSTV and many SSTV related infos, includes Fax basics

Build your own home made Antenna Analyzer with an arduino micro, or a cheeper one with a pic processor

Improvements to Using the Heath SB-200 Linear on Six Meters by Ron Klimas, WZ1V

Articles and original manuscripts on RF power amplifiers

Edited by Oz6OM to find out who's on 50MHz expeditions anywhere around the world. Most recent news on the web.

Eham IC-718 reviews

Guy wire sloper antenna suitable for the 10m band

A table with Loss in DB/100m , Max power in Watts, Diameter in mm , Velocity factor (VF) expecially in VHF UHF and Microwave

Windows freeware database containing frequencies, locations, and a small logging program capable or recording audio

Improved Helical Antenna Design for 802.11b WLAN by PA0HOO

IC-746 radio control program in italian and personale info

What do you do with a bunch of old computer power supplies?

Thermocouple ammeters are very rare these days, but the job they were perfect for - measuring antenna currents - is still a modern requirement especially in respect to groundplane currents. By David A. Reid PA3HBB G0BZF