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Topic regarding a new 1KW HF power amplifier with 2x GI7B

Short basic informations on QRP

The Voice of America (VOA) website serves as a primary digital platform for its international news and information services, broadcasting in 44 languages. The resource presents a wide array of current events, geopolitical analyses, and cultural reports, reflecting a global perspective on news originating from the United States. Content spans various regions, including Africa, Asia, the Middle East, and specific country-focused reports from VOA's language services, such as VOA Uzbek, VOA Kurdish, and VOA Russian. The site features top stories, special reports, and sections like "All About America" and "VOA Explains," providing in-depth context on US-related topics and global issues. The VOA platform offers a continuous stream of updated news articles, covering political developments like government shutdowns, diplomatic relations, and international conflicts, alongside social and economic issues. It also includes sections for "Worth Watching" videos and "From VOA's Language Services," highlighting the breadth of its multimedia output. The content is designed to inform a worldwide audience, often presenting multiple perspectives on complex international events and US foreign policy, making it a significant reference for those monitoring global news and shortwave broadcast content.

AA5TB homemade balun article

An home-brewed morse code CW filter with a central frequency of 800hz and a variable bandwidth from 230hz to 26hz by F5RDH in french.

Article about homebrewing a G5RV antenna by KC6CFF

ACOM 1000 modification uses electric band switching, such that both 6m and 4m operation can be maintained.

This homebrew six-meter linear amplifier started off life as a "junker" Alpha 76PA h.f. amplfier. Power output is 800W

The circuit is based on two AD8307 log amplifiers, which are connected to the forward and reflected ports on a directional coupler

A remote control box for the SG-237 that allow to turn on and off, check status the SGC tuner remotely by AA5TB

A homebrew dummy load is usually a combination of several parallel carbon resistors, in order to be able a final resistance of 50 Ohms.

A project for a home made 5 element yagi-uda antenna for 2 meters, covering 144-148 MHz band by N1BMX

Transistor and its history and lot of related infos

Nowdays lots of people are putting up antennas to either beam in different directions at the same time or just to stack them and get a lower angle of radiation. Use this stackmatch to match you array.

Building a cavity resonator for 144 MHz

By Justin Glasener K9MU

Homebrew G5RV a simple multiband antenna. This article shows detailed pictures of a G5RV home made antenna, including antenna size and dimensions by 9M2ZAK

A Solid State HF Amplifier with 16 mrf150 featuring 2.4 kW 1.8 MHz - 30 MHz

The document is a technical guide on designing RF filters for radio frequency applications. It covers topics such as interference suppression, band-pass filters, and low pass filters, with a focus on filter design and circuit filters.

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

A 40/80 meters dipole made with two loading coils based on a project by IK1ZOY

If your doing any home brewing gear for ham radio its a great idea to have a dummy load. This will to your radio be the perfect antenna...it will never radiate but your radio sees a perfect 50 Ohm impedance.

Offer a wide range of homebrewing projects mainly for VHF UHF operations. From vhf antennas to preamplifiers, chargers and power supplies

2,6 and 10 meters beacon located at Lake White, Ohio

7N3WVM homebrew project of a 3 W output CW transceiver on 7 MHz band

A VHF UHF 5+5 elements yagi antenna by CE4WJK

The HB9DHG Contest Calendar aggregates contest information, offering direct links to official rules and past results for various amateur radio competitions. It features a curated list of events, with a focus on HF and digital mode contests, ensuring that operators can quickly access relevant details for upcoming and historical events. The calendar is regularly updated to reflect the latest contest schedules and rule changes. Each entry typically includes the contest name, dates, and a direct link to the sponsoring organization's page, such as ARRL or DARC, where full regulations and scoring information are available. This resource streamlines the process of finding contest specifics, which is crucial for effective pre-contest planning and post-contest analysis. Validation and checking of contest information are emphasized, providing a reliable source for operators planning their contest activity throughout the year. The calendar supports both CW and SSB modes, alongside various digital modes.

Building a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.

Centre fed half wave dipoles make great, simple and effective antennas for the HF bands. Sometimes however, the centre feed is not ideal. This great project will improve the overall antenna performance.

Demonstrates a practical approach to improving Morse code proficiency through a curated selection of audio files. The resource offers downloadable MP3 files designed for CW practice, catering to operators aiming to increase their copying speed and accuracy. Content includes both standard words and specific amateur radio callsign groups, which are crucial for effective on-air communication. The files are organized to facilitate progressive learning, allowing users to select material appropriate for their current skill level. This collection supports the development of essential CW operating skills, particularly for those preparing for contests, DXing, or general ragchewing on HF bands. The _ON6ZQ_ site, maintained by _Christophe David_, also features information on his _Reverse Beacon Network_ skimmer and _SOTA2APRS_ feed, indicating a strong focus on active operating modes and digital integration.

A magnetic longwire unun with a T130-2 Iron Powder core by M0UKD

VHF UHF diplexer by G8MNY

Comparison of 50 and 70 Mhz antennas, commercial and home made projects

This Artificial Ground has been designed by Colyn Baillie-Searle GD4EIRP

A homebrew Magmount for 2m antenna

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

Building a high voltage (5KV), variable plate capacitor (17 to 220pF)

LM is a program to edit contest logs afterwards, a so-called contest post processor. With help of LM you can convert row data to many different file formats. Allow a quick input interface, and contest score for several contest. Can import & export a batch of logs and to create result lists.

Balun case construction, tipically to host toroid cores. Size of case depends on power to handle. By DL5DBM

A project for a SDR receiver by Juan Domenech Fernandez

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.

Homebrew a 2 meter square dipole antenna

An off centre fed dipole, with 10 feet of vertical radiator. It needs no tuner on 40m, 20m and 10m by M0UKD

Ebook by Akira Matsuzawa Tokyo Institute of Technology, Building blocks in RF system and basic performances, Device characteristics in RF application , Low noise amplifier design, Mixer design and Oscillator design

Homebrewed handheld RF powermeters for various sensors by DL5NEG

A homebrewed antenna for 2m handheld radios by TB1BIG

The MicroBeacon is the combination of a memory keyer and controllable RF attenuator.

Presents a QRP AM/CW transmitter project specifically designed for the 10-meter band, utilizing a crystal oscillator and a collector-modulated AM oscillator. The design employs a 2N2219(A) transistor in a Colpitts configuration, generating 100 to 350 mW of RF output power depending on the 9-18 Volt supply voltage and modulation depth. Frequency stability is maintained by a 28 MHz crystal, with fine-tuning possible via a Ct1 trimmer capacitor for approximately 1 kHz adjustment. The resource details the RF oscillator stage, implemented with a 2N2219 NPN transistor, emphasizing frequency stability and low power dissipation. It also covers the amplitude modulation stage, managed by a 2N2905 PNP transistor, which impresses audio information onto the carrier. Selective components (C3, C4, C7, C5) enhance voice frequencies within a +/- 5 kHz bandwidth, and modulation depth is controlled by R2 and R3. The project includes a 3-element L-type narrow bandpass filter (Ct3, L3, C10) to suppress harmonics and ensure a clean output signal. The project provides a complete schematic diagram, a comprehensive parts list including specific capacitor, resistor, and inductor values, and construction notes for the coils (L1, L2, L3). It also offers practical advice on enclosure requirements, suggesting an all-metal case or a PVC box with graphite paint for RF shielding. Operational parameters such as current draw (27mA@9V to 45mA@16V) and input impedance (50 Ohms) are specified, alongside guidance on antenna matching and the importance of a valid amateur radio license for 10-meter band operation.

A simple simple sweep generator circuit design where the sawtooth is generated by the PNP transistor and a 555