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This article will help to unravel some of the mysteries as well as giving useful operating tips to maximize your chances of working that rare station

A Working analysis of the gamma match problem that gives useful practical results in a article dated April 1969.

RCKLog is a windows freeware program for logging and administration of SSB and CW-Contest with simultaneous control of transceiver and real-time operation of Packet-Radio.

Cheap Antennas for the AMSAT LEO Kent Britain WA5VJB

An Off-center-feed antenna that covers 80, 40, 20, 17, 15, 12, 10, and 6 meters

Every ham needs an RF power meter. Here is a high performance unit to build at home.

A free to download and print, paper log sheet useful for portable amateur radio operations, in a PDF file.

Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

Notes on Axial-Mode Helical Antennas in Amateur Service. Helix Basics, Modeling Issues, and Short Helical Antennas Over Perfect Ground

How to operate on 10 and 20 meters in limited space with this trapped dipole.

Transistor and its history and lot of related infos

N1HFX article on adjustable voltage regulator

A PDF presentation of a home made moxon antenna for 50 MHz 70 MHz and 144 Mhz. The project is mainly out of surplus plastic Plumbing pipes and clips etc, and also details of how the dimensions were calculated.

This document details the design and construction of a Vinecom 6N4 dual-band Yagi antenna for the 50MHz (6-meter) and 70MHz (4-meter) amateur radio bands. The antenna features 9 total elements (4 elements for 50MHz, 5 elements for 70MHz) on a 4.236-meter aluminum boom. Computer simulations using MMANA software predict 7.21 dBd gain on both bands with front-to-back ratios of 16.01dB (6m) and 15.37dB (4m). The design uses 12.7mm diameter elements mounted on a 32mm square boom, weighing 5.7kg total. Practical measurements with an MFJ-269 analyzer confirmed good SWR performance across both bands after element length adjustments.

The document provides a comprehensive overview of baluns, which are devices used to connect balanced loads, like dipole antennas, to unbalanced inputs, such as coaxial cables. It covers various types of baluns, including voltage and current baluns, and their design, construction, and testing. The text discusses the importance of baluns in preventing RF currents on coax shields and their applications in Ham radio setups. It also includes practical advice on selecting and using baluns based on antenna impedance and power ratings, along with detailed performance evaluations and construction tips for different balun configurations.

5 elements Yagi antenna with an 8.7 db gain

If you have space constraint at your QTH for a HF antenna, you can try contructing this HF magnetic loop antenna for 40-20 meters bands

This is a design for a stealthy HF multi-band vertical wire antenna using a tree as a supportby G7AQK

A bowtie antenna is a type of antenna that reputedly provides higher gain at lower radiation angles than a center-fed dipole antenna at heights considerably less than 1/2 wavelength above ground.

This document contains the detailed instructions to build a homemade lindenblad antenna using a twin-lead as dipole elements. This document contains 9 pages and includes a detailed construction sequence and some drawings to build this antenna for UHF and VHF ham radio bands

An active receiving antenna for 10 KHz to 20 MHz, a very small sized antenna with excellent performances in noise to signal ratio.

Homebrew a compact yagi antenna for 14 Mhz suitable for those with small plots based on a design by AB4GX

A home made yagi antenna featuring 6db forward gain and 22 Db front back

A sourge arrestor for PL 259 connectors. A voltage surge arrestor to limit the voltage that may come back down the wire or coax after there has been static build up

A solutiom for the Ameritron AL-811(H) RF power amplifier, burnt panel meter lights. A common failure with the Ameritron AL-811 and similar amplifiers is that the panel meter lights burn out prematurely. These bulbs are usually integrated into the actual panel meter. The solution for this is to provide the meter backlighting with LEDs.

A 21 MHz Four Square Beam Antenna This popular antenna for the lower bands, can also work well on 15 meters, QST Article

The GW3YDX Super Moxon antenna design improves upon the standard Moxon Rectangle by incorporating additional directors in a rectangular configuration, yielding enhanced directivity and gain. For the 6m version, modeling with 4NEC2 and EZNEC+ indicated a 3dB gain increase and a 26.5dB front-to-back ratio, with VSWR below 1.5:1 between 50.0 and 50.3MHz when optimized for 50.1MHz. This design achieves a narrower -3dB power point beamwidth of 60° compared to the original Moxon's 80°, contributing to better QRM rejection. The boom length for the enhanced design is just under 2m, approximately double the original Moxon's, with no increase in wingspan. Construction details include tubing lengths for 6m, 4m, and 2m versions, with specific dimensions provided for elements A through M, measured to tubing centers. For instance, the 6m version uses a 2160mm element A and a 2140mm element H. The design maintains a 50-ohm feed impedance, with practical models showing VSWR plots consistent with simulations after minor adjustments to driven element lengths. The article also references Moxgen software for initial Moxon parameter calculation and NEC/EZNEC model generation. The 2m Super Moxon version measures approximately 30" x 25", demonstrating the compact nature of the design across different VHF bands. The article highlights the antenna's performance in real-world DX contacts on 6m, achieving contacts with over 80 stations in the USA from a modest QTH.

Improper grounding or earthing system can cause several unwanted RF interferences (RFI) to television sets, broadcast receivers, hi-fi sets and telephone sets. In this Article the author explain how to setup a proper radio shack grounding using coaxial cable and ceramic disc capacitor

Build this cheap and easy satellite downlink antenna

Service manual in PDF Format for the Yaesu FT-7800 transceiver

An end fed 20 meter half wave antenna

Key your transmitter from the tone output of a Morse Code generator program

VHF UHF diplexer by G8MNY

Presents the construction of a 6-meter (50 MHz) Moxon wire beam antenna, detailing the use of #14 AWG THNN stranded wire and a treated wood frame. It covers the assembly of a galvanized pipe mast, emphasizing the use of pipe sleeves for joint reinforcement over threaded couplers to prevent breakage during raising and lowering operations. The resource also describes the integration of a 1:1 current balun, rated for 50-54 MHz, and the use of RG-8X coax for the transmission line, recommending low-loss alternatives like Belden 9913-7F. Further, it outlines a manual rotation mechanism using pipe hanger clamps and carriage bolts for true North orientation, incorporating magnetic declination calculations from NOAA. The antenna's performance is discussed, noting good gain and take-off angle, with SWR tuning facilitated by a Palstar AT-500 manual tuner. An EZNEC+ 5.054 model for the antenna is available for download, alongside predicted radiation patterns and SWR curves, compared with actual AIM-4170C measurements.

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

An 80 meter band vertical loop antenna setup

A 2-metre Quad antenna project by K6WXA in PDF file

Part 2 You're now much closer to saying goodbye to your unwanted signal problems!

A PDF presentation about Amateur Radio and Linux by By: Dave Mamanakis. A beginners guide to Linux for radio amateurs, this presentation cover basic concepts of the open source operative system, from the basic installation to the setup of ham radio programs.

A compact antenna for 160 meters, suitable for hams tha want operate top band buh have a limited space

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

An home made vertical dipole antenna made with simple material. The antenna has a total length of aproximately 16 feet. In this article appeared on June QST 2019, the author explain how he reached the optimal confirugation changing and adjusting the lower part of the antenna, trimming and spacing correctly the copper wire. PDF File to downloas

2 x GI7B in push-pull 2m and 6m 1kW Power amplifier from PA0ZH

A scanned PDF of this interesting book on HF Dipole antennas published by Stanford Research Institute

Roger, G3XBM, shares his extensive experience in **QRP** (low-power) amateur radio operation, detailing various aspects of transmitting with minimal power. The resource provides insights into VLF (Very Low Frequency) reception techniques and the construction of simple **crystal radio sets**, reflecting a foundational approach to radio experimentation. It includes links to external resources covering QRP clubs, online receivers, manufacturers, and technical references, offering a curated collection for enthusiasts. His page serves as a hub for those interested in the challenges and rewards of QRP, often comparing the efficacy of different low-power setups. The practical application extends to understanding basic radio principles through hands-on projects like crystal sets, which G3XBM has explored. The collected links provide a starting point for further research into specific QRP equipment or operating practices, drawing on G3XBM's long-standing engagement with the QRP community.

This interface is intended to be used with all the popular digital modes like PSK31, RTTY, Olivia, etc., which modulate a continuous carrier.

The Cushcraft X7 Tribander assembly and installation manual (P/N 951470, 12/97) provides comprehensive instructions for constructing this 20-15-10 meter seven-element beam antenna. It details the sequential assembly of boom sections, individual elements, and the feed system, including the _MNX7 Matching Network_. The document emphasizes critical safety precautions regarding power lines and RF exposure, alongside recommendations for proper antenna system planning and grounding. Key sections cover verification of parts, detailed boom assembly using specific aluminum tubing (e.g., BA, BB, BC, BD, BE) and brackets, and element construction with various aluminum tube sections (e.g., EA, EB, EC, ED, EE, EF) and traps like the _15 Meter Director Trap_ (TB) and _10 Meter Director Trap_ (T9). It also specifies the use of _NOALOX® conductive lubricant_ for telescoping sections and hardware to prevent galling. The manual outlines the feed system assembly, which includes feed-straps (FL1, FL2, FL3), tuning-tube insulators, and the matching network. It also mentions the optional X740 40-meter add-on kit, which requires a separate coax feed. Detailed diagrams and parts lists with metric equivalents facilitate accurate construction and ensure the antenna performs as specified.

A multiband vertical dipole antenna by ON4BAI

Schematic of Yaesu FT-857 main board original jumpers based on different radio type

An excellently presented article on the design and construction of a medium wave DX Antenna