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Article on portable HF antenna where author diverge about antenna efficiency versus size based on his personal experience on using HF antennas during portable operations

Georgia District of SERA

1260 MHz yagi antenna for ATV with a total Bandwidth (3 dB) 1240-1280 MHz and 10 dBd gain

DMR Handheld TDMA Tier I and Tier II VHF or UHF product review with information on accessories

This page details (in brief) the component changes to modify a Cybernet series 27MHz CB transceiver to 50MHz.

These pricey battery-powered devices are the only type of generator that can be used indoors safely. The article reviews pro and cons of power stations evaluating runtime, power delivery, power quality, ease of use, and noise.

Bring the six meters with you during your hoilidays. This article features a portable moxon antenna for 50 MHz used for sota portable operatios

Over 500 downloads indicate _aLog365_ is a widely adopted mobile logbook for amateur radio operators, specifically designed for portable operations. It facilitates callsign lookup, real-time QSO uploads to _HRDLOG.net_ / _Ham365_, and offers CAT control via Bluetooth for radio integration. The application supports various export formats, including ADIF, EDI, CSV, and Cabrillo, ensuring compatibility with other logging software and contest submissions. Key features include an integrated DX Cluster and a DXpedition plan, providing operators with current propagation information and upcoming rare entity activations. A unique Instant QSL (iQSL) viewing capability allows for immediate confirmation of successful radio contacts. The app also supports SOTA, POTA, and WWFF operations, making it a versatile tool for activators and hunters alike. Developed by IW1QLH, the application is regularly updated, with the latest version improving performance and stability, and adding Spanish, French, and German language support.

Antique and Vintage Speaker Restorations for over 35 years. Grunow,Atwater Kent,Fairbanks Morse,McMurdo, Stewart Warner,to name a few.

A dual band X-frame wire antenna made using 4 turns for response down to 3 MHz or so, and 2 turns (switched) for response up to around 18 MHz. The loop configurations are tuned using common eBay 365 pF tuning caps.

This web page is part of a self-help program for licensed amateur radio operators and radio pirates.

FreePCB is a free, open-source PCB editor for Microsoft Windows, released under the GNU General Public License. It was designed to be easy to learn and easy to use, yet capable of professional-quality work.

The TARPN NinoTNC is a USB 1200/2400/4800/9600 baud KISS-TNC project

This is a simple 2.4 GHz SWR meter which is based around surplus microwave hardware which can be easily found. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2.5 GHz.

In the quest for an ideal field portable antenna, the author recounts experiments involving various wire configurations. While a previous candidate, a 41ft random wire, proved effective but lacked stealth, the search led to a surprising rediscovery of a design previously rejected—the Rybakov Antenna. With a focus on simplicity, rapid deployment, and multiband capability, the author explores the versatility of a 26ft Rybakov, avoiding the halfwave trap. The article delves into the antenna's performance and its potential as a discreet, resonant solution for field operations, addressing the challenges encountered during a POTA activation. Additionally, the Unun/Balun design used in conjunction with the Rybakov Antenna is discussed, providing insights into achieving a balanced system.

A list of links on Crystal Radio projects and related reources

DXFile is a Windows shareware application designed for amateur radio operators, providing comprehensive log management capabilities. The software, developed in Pascal, facilitates real-time and deferred QSO entry, automatically populating fields like frequency, mode, and DXCC country based on user input and system time. It includes features for searching, modifying, and deleting QSO records, with options to sort logs by date, callsign, or entry order. The program offers various printing functions, including QSL card labels in multiple formats, and can generate standard logbook printouts. Beyond basic logging, DXFile integrates modules for tracking progress towards major operating awards such as DXCC, _IOTA_, WAZ, WAS, DDFM, and DIFM. It provides detailed summaries of contacts by band and mode, including graphical representations of HF traffic. A dedicated QSL Manager module assists in processing received QSLs, allowing users to mark confirmations and print multi-line QSL labels. The application also incorporates a DXCC list viewer, which can be updated to ensure accurate country and zone data for logging and award tracking. A distinctive feature is its HF propagation prediction module, which calculates optimal frequencies and signal levels for paths between **250 km** and **6000 km**, considering both E and F layer ionospheric conditions. This module helps operators determine the best times for long-distance contacts. Additionally, DXFile includes a _Web-Cluster_ interface, enabling connection to various DX cluster servers like DXLITE, DXSCAPE, and NC7J for real-time spot information.

A web site dedicate to pedestrian and bicycle amateur radio mobile operations.

The author has build the Hermes-Lite SDR v1 and v2 versions describing with a very accurated text and picture the process. Additionally has documented measurements for each component

A multi section article on learning the morse code for beginners. The article include a list of tips the author consider to be uesful when someone want to begin the trip to learn the morse code.

Since 1992, MATsolutions has delivered the assurance our clients need when acquiring, maintaining, and managing high-quality test and measurement equipment. Used Electronic Test & Measurement Equipment Sales, Calibration, Repair & Services

A homemade MFSK16 APRS HF tracker, worked pretty well for 1.5W on a Lipo supply with only 2 of the 3 BS170 FETs in the final

The MiniPA Linear Amplifier for HF page discusses the popularity of QRP for HF among ham radio operators, such as those using the Yaesu FT818 or low power SDR transceivers. It explores the use of cheap kits from eBay or Chinese suppliers to build a 70-100W SSB amplifier using IRF530 MOSFET transistors. The article provides a review of the MiniPA design, including its features, components, and assembly process. It also highlights the importance of using a heatsink and forced air cooling for optimal performance. This page is useful for hams looking to enhance their HF rig with a budget-friendly amplifier.

eHam reviews of the Mirage BD-35 VHF UHF Amplifier

SMSS - Swedish Lakes. A Contest where you collect as many lakes as possible of over 100000 lakes.

TE Systems 0510G 50 MHz meter amplifier set up for 10 watts in and 170 watts out.

G0TRG - Trafford England

Common issue on the TYT MD-390 when the speaker start sounding like it is broken, but it depends by the external mic cover.

IOTA NA-018, 2012 Sep 11 - 2012 Sep 16 Mainly CW

The author reflects on expanding their antenna for 80m coverage during lockdown. They extend the End Fed Half Wave (EFHW) using a Spiderbeam pole and "cheating" by dog-legging across their garden. Despite challenges, they achieve coverage for multiple bands with minimal cost. Practical Wireless features EFHW antennas, including a pre-made 20m EFHW extended for 40m.

NARRI is to promote the development of amateur radio repeaters in Nevada USA

Probemaster manufacturers probes of all kinds, including oscilloscope probes, differential probes, test leads and much more, all proudly made in the USA

Tips and tricks on programming the Yaesu FT-991A, from software installation and connecting to the PC via the USB Port, to properly programming memories.

SERA Mississippi

The TCARES membership provides communications assistance with fires, floods, search & rescue, and health & welfare message assistance to the Red Cross, without pay, using their own equipment, usually in twelve hour shifts.

Modification to an old cellular phone base station modules, with a fairly reduced output power (10 watts or so), the stock power amplifier modules will cover the 2.3 GHz and 2.4 GHz amateur radio bands.

Building an End-Fed Half-Wave (EFHW) antenna from a kit, as detailed by Frank Bontenbal, PA2DKW, with process photos by Bob Inderbitzen, NQ1R, offers a practical approach for hams. This specific kit, a collaboration between ARRL and HF Kits, targets 10, 15, 20, and 40 meters, making it a versatile option for HF operations. Unlike a center-fed dipole, the EFHW is a half-wavelength antenna fed at one end, which simplifies deployment, particularly for portable use. The construction guide meticulously outlines the assembly of the 49:1 impedance matching network, crucial for transforming the antenna's high impedance (around 2,500 Ohms) to a transceiver-friendly 50 Ohms. Steps include preparing the enclosure by drilling holes for the coaxial connector and antenna connections, followed by the precise winding of enameled copper wire onto a toroid to create the transformer. The guide emphasizes careful insulation removal and soldering for reliable connections. Final assembly involves integrating a 100 pF capacitor for higher band compensation, soldering the transformer's primary and secondary sides, and conducting SWR tests with a 2K7 resistor or a half-wavelength wire. The document also provides examples of wire lengths for different bands, such as 16 feet for 10 meters or 66 feet for 40 meters, demonstrating the transformer's adaptability for various half-wavelength configurations.

Building an automatic 8ch USB Relay switch using an existing Ameritron RCS-8V Remote Control Coax Switch and an externally mounted 5-way switch.

The _G3TSO_ Mobile Antenna Page details construction and tuning methods for mobile antennas operating across **10 to 160 metres**. The content describes a Hustler-based design, optimized for RF performance and vehicle speeds, featuring centre loading. For optimal operation on various bands, the loading coil placement requires clearance from the vehicle body. Antenna resonance is critical for efficient mobile operation. A mobile antenna's base impedance may be as low as 27 ohms, requiring specific matching to achieve maximum radiation, as a minimum SWR at the transmitter does not always indicate resonance or maximum output. Tuning involves physical adjustment of antenna length to achieve resonance at the operating frequency. The _G3TSO_ page outlines a tuning procedure utilizing a low-power signal source and a field strength meter to identify maximum radiation before impedance matching. Loading coil placement, either at the base, center, or top of the antenna, influences radiation efficiency and mechanical stability for mobile installations. Centre-loaded whips, such as the Hustler design, offer a compromise between efficiency and stability, often for single-band operation. Helically wound antennas, including those for **28 MHz**, may present base impedances around 17 ohms, resulting in a 3:1 SWR at resonance. Low resistance grounding at the antenna base is also specified for optimizing performance and minimizing RFI during mobile operation. DXZone Focus: Mobile | Any | Antenna Tuning | HF

A home made morse paddle made with a perf board

Web site and blog that reviews equipment, goes over safety, and display projects being built. Includes Yaesu FT-891 and Ameritron RCS-10 Review, a 555 Morse Code Practice Oscillator, and and arduino based Morse Code Practice Oscillator

The author investigated electric field antennas and achieved promising results with a shortened active whip antenna (30 cm). The findings suggest that at LF, active whips function primarily through electric field capacitance coupling.

The Panther Amateur Radio Club is the student run radio club on Pitt's campus. The club's repeater sits 535 feet above the campus on top of the Cathedral of Learning.

This air-core solenoid style RF inductor calculator calculates the inductance, wire size, number of turns, and other parameters for an air-core solenoid inductor used in radio frequency (RF) circuits, based on user input of frequency, desired inductance value, and physical dimensions.

SDXF is a Swiss nonprofit organisation, founded in 1998 to help supporting amateurradio expeditions to rare places where little or no amateurradio activity exists.

SERA Kentucky

Amateur radio portable operation has a lot to offer, even if you are a shack sloth and have an awesome setup.

Creating a 2m Fm Repeater with a Raspberry Pi (B) and a RTL dongle.

Review of Yaesu VX-3R 2 m/70 cm FM transceiver. Receives 0.5-999Mhz AM/FMN/FMW, Transmits 144-148 and 430-450Mhz VHF/UHF FM.

An Inverted-L with its long leg sloping to the ground. It will still work very good, even if the horizontal wire has to be sloped diagonally to the ground, as long as you have enough horizontal space to keep it at about a 45 degree angle or more from the pole.