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G3WZT design for a bi-polar 600W Linear Power Amplifier for the 6M band.

Collection of modifications for the Heathkit SB-200 RF power amplifier

Engineering Solutions for Unique Problems. Manufacturer of high Voltage, high Current, high Power Power Supply

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

Ameritron Al-811H Tuning for Power/Dissipation/Linearity, and More Generally 811A Tube Amps in Grounded Grid

An RF power Amplifier for HF bands with 3 GI-7B tubes by CT1FMS

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

DIY kits a 70W SSB linear Power Amplifier for YAESU FT-817 KX3 running HF 80m-10m bands

A simple RF power amplifier initially designed for 40 meter band can work on 10 15 20 40 80 meters

A lower power desktop linear with integrated 120vac power supply. This, very compact, dual 811 version will deliver about 300 watts output. Covers all bands including WARC bands.

Baluns / Ununs design and acceptable power

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

The UK amateur radio licensing scheme features three distinct tiers: Foundation, Intermediate, and Full, each granting specific operating privileges. For instance, the **Foundation Licence** permits a maximum of 10 watts output power on most allocated bands, with restricted band access. The Intermediate Licence allows up to 50 watts, while the **Full Licence** grants access to the maximum UK legal power limits and all available amateur radio band allocations. UK call sign prefixes and formats provide insights into the licensee's class and the approximate issuance date. For example, M3, M6, and M7 prefixes with three letters denote Foundation Licences issued from 2002, 2008, and 2018 respectively. Intermediate Licences, often starting with "2E0" or "2E1" followed by three letters, were issued from 1991 onwards. Full Licences encompass a broader range of prefixes like G2, G3, G4, G0, and M0, with varying letter counts indicating different historical license classes and issuance periods, such as G3 plus three letters issued between 1946 and 1971. Special prefixes like GB are reserved for repeaters, beacons, data mailboxes, and special event stations, with specific numerical sequences (e.g., GB3 for repeaters, GB7 for data repeaters/mailboxes) indicating their function. Optional prefixes such as GC, GD, GI, GM, and GW denote specific UK countries (e.g., Wales, Isle of Man, Northern Ireland, Scotland, England) and can also signify club stations.

Small, but growing, group of amateur radio enthusiasts, most of whom are within 90 miles of Atlanta, are interested in promoting the development of the branch of amateur radio known as QRP - building and operating low power transmitters, receivers and transceivers.

High Power RF Amplifiers by Delta Sigma, Inc

An engineering oriented organization specializing in the design and manufacture of high performance parabolic antennas, 3dB high power RF couplers, Antenna power splitters, directional RF couplers and more items for RF transmission from HF through Microwave frequencies.

The two linear amplifiers are ment for use with QRP SSB/CW/FM/AM transmitters on the amateur bands 15 and 17 meters can be powered from a 12 volt DC supply by ON6MU

A perfect companion for your Elecraft K1 or any other (not power hungry...) QRP rig

HF power amplifier project powered by GU-78B by SV8JE

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.

This article provides a basis to brew your own emergency power pack depending on your needs and tastes.

ON6MU 4 A power supply using a BDX33

The Collins TRC-75 autotune linear amplifier, owned by JF2SVU, is presented with a focus on its internal modifications. This QRO amplifier utilizes three 4CX250 tubes in parallel for its final stage, delivering 1 KW output power. Notably, the amplifier achieves full power with only 100 mW of RF input, a characteristic often associated with Collins designs. The original 400 Hz power supply has been converted for easier shack integration, and the entire RF and power supply sections have been rehoused into a compact, clean enclosure. The control unit, positioned above the amplifier, features three meters for individual vacuum tube IP monitoring and a multi-meter on the right. A dedicated 7 MHz receiver, recently completed, is also part of this integrated system. The autotune functionality means the main amplifier unit only requires connections for power, control, and coaxial cables, simplifying its operation. Key components like the 4CX250 tubes and NF capacitors are visible, along with the gearing mechanism for the final tank circuit. A timer and relay system manages high-voltage delay and cooling fan off-delay, although the cooling fan's airflow is noted as somewhat insufficient. A central volume control, which experienced a contact issue, is also highlighted.

Modifications for the Kenwood TS-940, TS-940S LCD Clock Display Erratic Operation, Talk Power Improvement, erratic display, ALC mod

Class C tuned VHF power amplifier for the 6-meter band by ON6MU

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

Construction details of a multiband dipole that can can operate at high power levels, and match its 50-ohm coax feedline without a tuner

A Low -Power Indoor Portable HF Antenna by Monty Northrup, by N5ESE

SM5BSZ article on building VHF RF amplifiers

Receiver converter that can be plugged to the backside of the Yaesu FT-817 battery powered portable transceiver

How atenna tuners works and what are real effects on feed lines and maximun power output by G3TXQ

Interesting post with a practical video of using solar panel with a yaesu ft-857.

VoiceKeyDeluxe (VKD) will convert your sound card into a powerful and versatile digital voice keyer for contest or EME operations by N7QJP

An home made RF Amplifier project that allows near full power output from 813 tubes

20 Watt Power Amp for Softrock or for QRP transceivers by M0RZF

The digital wattmeter project was created for the purpose of measuring power in the range of 300nw to 30w.

RF and Microwave Power Amplifier and Transmitter Technologies, amplifierlinearity, efficiency and available RF power devices.

The Collins 516F-2 is a heavy-duty power supply for the KWM-2/2A transceivers and the 32S-1,2,3 series of Collins transmitters.

How the tube converts DC to RF Power

There is not a personal design on this page, just I've transfered useful notes from PHILIPS RF Bipolar Transistors - Data HandBook about BLY89C VHF Power transistor, which is very popular among Amateur Radio homebrewers

RF Power Meter using for reading a standard Digital Voltmeter by Iulian Rosu, YO3DAC / VA3IUL

PCB for the DJ9BV Power Meter taken from DUBUS 3/87

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.

Calculate power loss depending on coax cable you use

This little project will make a portable 28 Volt DC power supply using two 12 Volt, 4.5 Ah rechargeable lead-acid batteries

A power line noise eliminator designed to eliminate QRN expecially on 40 meters band.

This small, light weight digital SWR and power meter uses an Atmel AVR Butterfly demo board and a Stockton type directional coupler.

For macOS users engaged in amateur radio operations, a robust logging solution is essential for tracking QSOs, managing contest entries, and handling QSLs. RUMLog addresses these needs by providing a fully featured logbook program designed specifically for the Apple ecosystem. It integrates capabilities such as transceiver control for popular Icom, Elecraft, Yaesu, and Kenwood rigs, CW keyer interfacing, and real-time DX cluster monitoring. The software also includes mapping functions, callsign checking, and extensive import/export options for various log data formats. RUMLog's design supports both general logging and specialized contest operations, offering tools for efficient entry and submission. Its QSL handling and printing utilities streamline the confirmation process, a critical aspect for award pursuits like _DXCC_. The program's ability to interface with a wide array of transceivers via _Hamlib_ or proprietary protocols ensures broad compatibility, allowing operators to leverage its features across different station configurations. The free availability of RUMLog makes it an accessible option for macOS-based hams seeking a powerful logging utility.

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

A radio's transmitting power can be concentrated along the horizon by use of a GAIN antenna. Although you may still be transmitting with four watts of power, your effective radiated powerwill be greatly increased. This table shows the effects of antenna gain on a transmitter with 4 watts of transmit power.