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

Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency

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

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.

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

A simple circuit which will generate a 700 Hz tone into any FM transceiver allowing an amateur to practice CW with another amateur on a 2 meter simplex frequency.

W3EDP multiband wire antenna, an extensive study and analysis of this antenna by W0ESE

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

Gap Titan DX Antenna manual. This is an enhanced version of the common Gap Titan DX Manual document you can download from other sites. This manual is in PDF Format.

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

Transverter for 70MHz, a project by G3XBM

Progress in Design of Extremely Short Transmitting Antennas Short and still efficient, how is that possible? By Juergen Schaefer, DL7PE author of the MicroVert antenna concept. The MicroVert introduced in this document is an extremely short and hardly visible short-wave antenna with outstanding radiation properties

English version of the Yaesu FT-7800 operating manual

F5DQK repairing and swr measurement tests of a Cushcraft R7 Antenna

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.

KG4JJH moxon assembly plan for the 50 Mhz in a pdf file

The ultimate Keyhole Markup Language (KML) plugin for Google earth. Keyhole Radio is a unique and powerful RF planning interface, accessed by loading a Keyhole Markup Language (KML) overlay in Google earth.

Club dedicated to the world of Hellschreiber

A moxon antenna project for 70 cm band, test and results of this popular antenna model applies to UHF bands.

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

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

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

Sometimes amateurs like to home-brew their power supplies instead of purchasing one off the shelf at any of the major ham radio retail dealers.

Lighting protection document by Glen E. Zook

CWQSO allows you to practice sending and receiving CW in a real QSO!

An Arduino project to make it work as a KISS TNC

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.

An inexpensive condenser microphone with excellent performance can be easily constructed with easily available parts.

A project of a semi vertical trap antenna that can be tuned for 7 bands

The DL2NBY Contest Calendar, leveraging the Google Calendar system, presents approximately 400 **HF amateur radio contests**, detailing their dates and rules. It covers a broad spectrum of operating modes, including CW, SSB, and various digital modes like RTTY. The calendar integrates contest information from major organizations such as ARRL and DARC, providing a centralized repository for contest operators. This resource offers the capability to integrate contest events directly into a user's personal Google Calendar, streamlining contest planning. It functions as a comprehensive schedule, allowing operators to review upcoming events and prepare for participation across different bands and modes. The calendar's structure facilitates quick access to contest specifics, aiding in strategic contest operation.

The SARK100 Antenna Analyzer it is yet another antenna analyzer but available in kit form and designed to be easy to assemble and with an affordable pricing.

A PDF File to download and print, with a table of all menu options with values, default settings, description and a quick reference guide of the front panel menus

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

50 MHZ Moxon antenna based on the KG4JJH design with some slight modifications in the construction

A means of sync-ing your computer clock using a GPS Receiver. GPS2Time is another GPS network time synchronization software application for Window 7 and higher. Freeware.

This resource, "Transistor Audio Preamplifier Circuits," offers comprehensive design guidelines for constructing **bipolar transistor** audio preamplifiers. It delves into critical aspects such as quiescent current setting, voltage gain calculation, and the impact of various component choices on circuit performance. The content provides several _schematic diagrams_ illustrating different preamplifier configurations, including single-stage common emitter and two-stage designs, alongside explanations of their operational characteristics and practical implementation considerations. The analysis extends to frequency response, noise performance, and distortion, providing insights into optimizing these parameters for specific audio applications. The resource presents calculated gain figures for various stages, demonstrating how to achieve desired amplification levels. It also discusses the importance of proper power supply decoupling and input/output impedance matching, crucial for integrating these preamplifiers into larger audio systems or ham radio transceivers. The practical application of these designs is evident in their suitability for microphone preamplifiers or general-purpose audio amplification.

Demonstrates the design and construction of a compact, portable multi-band mini-delta loop antenna, specifically optimized for /P (portable) operations from remote locations like Scottish islands. The resource covers the theoretical underpinnings of half-wave loops, contrasting closed and open configurations, and then details the application of a folded dipole principle to achieve a 50-ohm match for direct coax feed. It presents empirical formulas for calculating element lengths, considering the velocity factor of common wire types, and provides a detailed example for a 20m (14.175 MHz) version. The article includes a comprehensive table of dimensions and allowances for a five-band (20m, 17m, 15m, 12m, 10m) mini-delta beam, along with construction hints for the central support and balun. It specifies a 1:1 trifilar balun wound on a ferrite rod and describes the antenna adjustment process using an _MFJ-259B Antenna Analyser_. Initial test results indicate an SWR of 1:1 at resonance and a bandwidth of approximately 240 kHz on 20m, even at a low height of five feet above ground. The distinctive utility lies in its focus on a practical, easily deployable beam antenna for portable DXing, offering a viable alternative to more complex or larger arrays.

How to Increase your CW speed article by George Allison, K1IG as published on QST

This grid locator map uses Google map apis to find your QTH locator by simply clicking on the map. You can either enter your QTH locator and find the calculated distance and bearing between your QTH and another grid square.

GW4ALG's _136 kHz Pages_ document the evolution of vertical antennas for the 2200m band, starting with a prototype mounted on a house wall. This initial design, despite achieving the first **395 km** GM-GW QSO, suffered from significant insulation breakdown, high RF losses due to proximity to the house, and difficult tuning adjustments. The author details the challenges of maintaining resonance and matching with a variometer in the loft, noting that adding three earth spikes offered no measurable improvement over a simple water tap connection. The subsequent experimental 12m vertical, relocated away from the house, significantly reduced dielectric losses and proved far more effective. This antenna enabled GW4ALG to set a world DX record on 136 kHz with a **1916 km** QSO to OH1TN, and an intra-UK record of **703 km** to GM3YXM/P. The resource further explores the use of helium-filled balloons to extend the vertical radiator, achieving heights up to 27m, typically 20m, for enhanced low-band performance. Practical advice on balloon types, inflation, and critical insulation between the wire and balloon is provided, emphasizing safety and avoiding arcing.

The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF

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.

A 3 element yagi antenna project for the 144 MHz band by PY5ALZ in portuguese

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

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.

A small antenna for limited space / lanai use.

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

A simple antenna tuner for 4m by Tony Hawker G4CJZ

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