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Constructing a high-power 70cm solid-state amplifier presents unique challenges, particularly when aiming for 500 watts output using modern LDMOS devices. This resource details the author's experience building a 70cm amplifier based on a _Freescale MRFE6VP5600H_ transistor, initially from an RFHAM kit. It meticulously outlines the necessary modifications to achieve advertised performance, including optimizing input and output matching, correcting bias circuitry, and ensuring proper output balun connections for stability. The author shares specific adjustments, such as trimming the prototyping board for better transistor fit, drilling additional mounting holes for improved heat sinking, and replacing original matching capacitors with a single _20pf MIN02 metal mica_ for superior output. A critical fix involved jumpering gate decoupling pads to balance the push-pull transistor halves, which increased output to 580W and improved IMD. The resource also highlights a crucial correction to the output balun connection, initially reversed in the _Dubus_ article schematic, which resolved intermittent stability issues. Test results are provided, showing input power, output power, and drain current at 50V, demonstrating the amplifier's performance after modifications. This practical account offers valuable insights for hams undertaking similar high-power UHF amplifier projects, especially those working with LDMOS devices and kit-based constructions.

A simple free running oscillator oscillating at the receiver\'s IF (intermediate frequency) beats with the incoming signals in either CW or SSB and the resultant audio frequency goes to the AF amplifier.

Yaesu VX-6R eham.net users review

Is a group who enjoy gathering together to practice the hobby of Amateur Radio.

Collection of Kenwood TL-922 linear amplifier modifications

Local amateur radio clubs often serve as vital hubs for hams to connect, share knowledge, and participate in group activities. The Orleans County Amateur Radio Club (OCARC), operating under the callsign WA2DQL, provides a focal point for amateur radio operators in Albion, New York, and the surrounding Orleans County area. These organizations frequently host events, offer technical assistance, and foster camaraderie among members, supporting various aspects of the hobby from contesting to emergency communications. OCARC's activities include discussions on proposed Technician class privileges for **80, 40, and 15 meters**, indicating an interest in regulatory changes affecting entry-level licensees. The club also promotes the use of online tools like _Radio Mobile Online_ for antenna pattern analysis and _VOACAP Online_ for propagation predictions, aiding members in optimizing their station performance. Furthermore, OCARC highlights participation in _Parks On The Air_ (POTA) events, such as the Erie Canal Bicentennial Celebration in 2025, encouraging outdoor operations and public engagement with amateur radio.

Yaesu vx-8r prototype quad-bander on display at the 2008 dayton hamvention. Youtube video

Approximately 2.8% annual decline in Australian amateur radio licenses was observed over the five years leading up to 2002, a trend that prompted further analysis of the country's amateur population. This resource examines licensing statistics and demographic shifts within the Australian amateur radio community between 1998 and 2007, utilizing available data to identify patterns in license issuance and renewal. The study focuses on **population trends** and the underlying factors contributing to changes in the number of active **amateur radio operators**. It provides insights into the health and growth trajectory of the hobby in Australia during this specific period. Understanding these demographic shifts is crucial for clubs, regulatory bodies, and equipment manufacturers to adapt strategies and foster engagement.

Ham radio wire antennas are the most common form of antenna used by ham radio operators. Here you can find hints and tips on diy wire antennas

eHam users reviews on the TS-480SAT

Solar Power for Your Ham Station, It is Easier Than You Think QST article April 96 by KE0OG via Repeater-Builider.com

Established around 1968, the Wichita Amateur Radio Society (W.A.R.S.) N5WF provides a central hub for amateur radio operators in the Wichita Falls, Texas area. The society actively supports local ham radio interests, fostering community engagement and technical development among its members. W.A.R.S. is known for its commitment to public service communications and promoting the amateur radio hobby through various activities and educational initiatives. The society's activities often include field operations, technical presentations, and participation in emergency communications drills, which align with its mission to support the amateur radio community. Members frequently engage in _DXing_ and _contesting_, sharing their experiences and knowledge to help others improve their operating skills. The club also maintains local repeaters, providing essential infrastructure for regional communications.

Zveza Radioamaterjev Slovenije

The mark 2 Crossfield Antenna was described in Sprat 76 by Alec, GD3HQR

eHam reviews for the Ameritron AL-811 linear amplifier

Ham radio Blog, focusing on homebrewing and testing antennas, rig mods and contesting.

Wrexham is in North Wale's and our club is open to all radio fans

PDF file of the Yaesu FT-991 manual

The Megacycles combine the hobbies of amateur radio and bicycling. This group is not a club as there are no officers, dues or by-laws.

Running 10 and 6 meters beacons, 6 m and 70 cm fm repeater from Melbourne, Australia

Operating as a local amateur radio club, the Wireless Association of South Hills (WASH) provides a community hub for hams in the Pittsburgh, PA area, identified by the N3SH callsign. The club engages in a range of activities including the Annual Field Day, the PA QSO Party, and a 2 Meter Contest, fostering participation in various aspects of the hobby. WASH also supports local ARES/RACES efforts, highlighting the critical role of amateur radio in emergency communications during disasters, and facilitates ARRL/VEC exam sessions for new licensees. Beyond contests and emergency preparedness, WASH hosts club picnics and an annual hamfest, promoting social interaction among members. The club maintains VHF/UHF repeaters, which are essential for local communication and extending range for members. Regular activities include a Monday evening WASH NET at 8:00 PM, providing a consistent on-air gathering point. The club's focus on both recreational and public service aspects of amateur radio, from making new friends to providing vital disaster communications, underscores its comprehensive approach to the hobby.

Durham FM Association DFMA Durham Ham Radio Club - Durham Amateur Radio Club - Durham, NC

Here a comparison of Kenwood TS-590S used with MC-60A and the oringina dynamic microphone

Map of VHF UHF repeaters in australia

The Buddipole Deluxe, a portable HF/VHF antenna system, receives a practical assessment from IW5EDI after a month of field use. The author, constrained by antenna restrictions, highlights the system's crucial role in enabling portable operations, even managing sporadic digital activity from a balcony. Direct comparisons to a fixed 3-band dipole reveal surprisingly comparable signal reports on 15, 17, and 20 meters, underscoring the Buddipole's effectiveness in real-world scenarios. Tuning the Buddipole proves straightforward on bands down to 20 meters, though the review notes significant challenges with SWR on lower bands like 40 meters, where achieving better than 3:1 SWR was problematic. Observations also include SWR variations with dipole rotation and mast height, suggesting environmental factors play a role. The overall manufacturing quality of the antenna and its accessories, including the tripod and carry bag, is deemed good, despite a minor issue with a pole connector. Looking ahead, the author plans to construct a homemade Buddipole version, possibly optimized for the 30-meter band, specifically for PSK31 operations from an apartment. This personal project reflects a common amateur radio practice of adapting commercial designs for specific needs, further extending the utility of portable antenna concepts.

Home build a Kenwood PG-5A cable. This lead is the audio data cable for some of the Kenwood Mobile transceivers

OM3CPH Universal HAM radio/generator DDS Unit with AD9850 or AD9851

WA7LAW.COM is a site to support the activities of the Snohomish County Hams Club and for the use by ALL amateur radio operators in and around Snohomish County, club members or not.

eham users reviews of the Kenwood TS-570S(G) series

How to measure the characteristic impedance of a unknown transmission line using MiniVNA

Several bash scripts are provided to automate common amateur radio tasks on Linux and FreeBSD systems, addressing the need for quick access to specific data without navigating web interfaces. These utilities include `call` for fetching US callsign details from callook.info, `qth` for obtaining address information for US and Canadian callsigns, and `grid` for determining grid squares based on license addresses. Each script is designed for command-line execution, allowing for single lookups or interactive sessions, and emphasizes a KISS (Keep It Simple, Stupid) programming philosophy. Another script, `au_kp.sh`, is tailored for weak signal VHF operators, fetching and displaying the NOAA 30-minute Aurora forecast and GFZ Space Weather Kp index data. This script generates static images, requiring re-execution for updates, and is intended to be run as a clickable desktop object for real-time space weather monitoring. It helps operators track propagation conditions, especially during solar cycle peaks. Beyond bash scripts, the resource offers a PHP/web page `fortune` implementation, including Henrik Aasted Sorensen's PHP script, sample HTML/CSS, and a HOWTO guide for creating fortune files. W3DHJ provides several amateur radio-themed fortune files, such as "Ham Humor & Wisdom" with 354 entries and "VHF Rover Humor & Wisdom" with 223 entries, along with other general humor and wisdom collections. These fortune files are designed with embedded HTML for web page display and are refreshed monthly, offering a total of 21,400 entries.

Microcontrollers for many ham radio applications including repeater controllers, beacon transmitters, keyers, antenna switches, battery monitors, etc.

CQHAM.ru page about the Kenwood TM-241

Adapting a Wouxun/Kenwood USB cable as a Yaesu FT-817 FT-857 FT-897 CAT connection

This app permit to work in DigiModes using the latest free version of HamRadio Deluxe Suite 5.24.0.38 with the new Yaesu FT-991 (which is not supported in that version of the application) using the Yaesu FT-950 model in HRD

Amateur radio installation services and products for sale. Tower erection services, shack setup, antenna installation

About the Cushcraft A3S with A743 add-on for 30 an 40 meters

Home-Made Magnetic Loop Antenna for 30 Meters by WA8LMF

Yaesu VX-8R eham users reviews

Make and automatic antenna tuner based on Arduino and using economic card. This ATU Project can be installed outdoors and controlled remotely by an rs485 link

This online database, called HAMLOG, can be used free of charge by any radio amateur worldwide.

ARRL special service club

Information on establishing an amateur radio station in japan

Demonstrates the swift setup process for a **Trans World Antenna**, showcasing its utility for portable amateur radio operations. The video highlights the antenna's design for quick deployment, a critical factor for activations like Summits On The Air (SOTA) or Parks On The Air (POTA), where efficiency in establishing a station is paramount. It illustrates the physical components and the sequence of assembly, emphasizing ease of use in varied field environments. The antenna system is presented as a multi-band solution, capable of operating across various HF frequencies. This adaptability makes it a versatile choice for hams engaging in outdoor activities or emergency communications. The visual demonstration provides practical insights into managing the antenna elements and feedline for optimal performance during temporary deployments. The focus remains on the practical aspects of field setup, rather than detailed technical specifications or performance metrics.

Ham Radio and Computer gear in Huntsville, Alabama

How to run an SDR Receiver on the Android Google Nexus 7 using SDR Touch App and an RTL-SDR dongle, review and costs by IW5EDI

A RF Probe circuit for the RADIO frequency experimenter to check the presence of a RF signal and also to measure its strength

This article describes an alternative to water as the cooling liquid for amateur radio vacuum tube power amplifiers. This cooling system is designed for adequate vacuum tube cooling, reasonable cost, and very low maintenance. By K8CU

Thierry LOMBRY, ON4SKY, develops in depth and with original pictures the long history of amateur radio all through the world from 900 BC to date.

Microphone tips for the Icom 706MkIIG