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An amplifier made using an old HT-41 Hallicrafters Amplifier and adding the 160 meters band By W4NFR

eHam reviews for the Ameritron AL-811 linear amplifier

This video will provide a foundation for understanding how power amplifier circuits work. If you are new to High Frequency Power Amplifier Circuit Design, this is the place to start.

Home Brew a 4-1000A RF power amplifier project by W4NFR

Operating the _Icom IC-746_ HF/VHF transceiver often presents specific technical questions, and this resource compiles a comprehensive Frequently Asked Questions (FAQ) document in an ASCII text format. It details common inquiries and solutions related to the rig's functionality, accessories, and potential modifications. The content is structured into distinct sections addressing general information, power supplies, antennas, microphones, keyers, amplifiers, TNC integration, and optional IF filters. The FAQ provides practical guidance on topics such as configuring the internal automatic antenna tuning unit (ATU), selecting appropriate power supplies, and understanding microphone pin-outs. It also delves into advanced subjects like computer control via CI-V, wiring for PSK31 operation, and troubleshooting common issues like low S-meter readings on 2m FM or loose tuning shafts. Specific questions cover the installation of optional IF filters, comparing Inrad versus Icom filters, and optimizing filter combinations for various modes. Furthermore, the document outlines various hardware and firmware modifications, including those for increasing monitor volume, replacing LCD driver transistors, and implementing a "poor man's TCXO." It even touches upon untested modifications, such as replacing PIN diodes in the demodulator. The FAQ also lists manual errata and discrepancies, offering a robust knowledge base for IC-746 owners seeking to optimize their station or resolve operational challenges.

EB5AGV Workbench: Yaesu FL-2100B amplifier restoration

A 160W linear amplifier for 4 meters band based on GI0GDP

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

Replacing the Yaesu FT100D SRF7043 VHF/UHF RF MOSFET Power Amplifier

Software defined radio products. Maker of AFEDRI SDR a direct sampling Software Defined Receiver by 4Z5LV

Design Guidelines for JFET Audio Preamplifier Circuits By Mike Martell N1HFX

Changing band selector to a Kenwood TL-922 power amplifier by IW1PUR in italian

Explains the fundamental principles of Software Defined Radio (SDR) and Digital Signal Processing (DSP) within the amateur radio context, serving as an initial entry point for hams interested in these technologies. It covers the architectural shift from traditional analog hardware to software-centric radio systems, detailing how digital signal processing algorithms are applied to modulate, demodulate, and filter radio signals. The resource compiles a list of external links to _white papers_ and project pages, offering further technical depth. This page provides a foundational understanding of SDR/DSP, enabling operators to grasp concepts like direct sampling and quadrature mixing. It references various projects and discussions, allowing users to explore practical implementations and theoretical underpinnings. The curated links direct users to resources that might cover specific SDR hardware platforms or software applications, facilitating deeper research into the subject.

Manual of the BD-35 Dual Band VHF UHF RF power amplifier by Mirage Amp

The Superphaser-2 is an antenna phasing unit based on the PSA-A Phase Shift Amplifier module

A 600W 1.8 MHz to 54 MHz power linear amplifier made using rugged MRF300 transistors featuring output power between 580W and 750W depending on band, power supply: 48V, 18A typical, 20A max

A home made 50 MHz KW power amplifier project with picture and PCB schematic by W6PQL

Mods.dk collection of Ameritron ALS-600 power amplifier

HF Linear Amplifiers, maker of the HAL600 Atlantic atomatic HF Amplifier

The document explains the technical aspects of how the Internet Radio Linking Project (IRLP) works, focusing on the use of VoIP streaming software under the Linux operating system. It details the audio sampling, compression, transmission, reception, and playback processes involved in IRLP communication.

L4B by Drake amplifier mod

Demonstrates the _RoMac Automatic CW Identifier 2012_ software, a Windows application designed to automate station identification and provide a tuning pulser. It can send CW identification via a sound card's audio output or by keying a radio's manual CW jack using a serial port's DTR line. The software also supports CAT commands for various Kenwood, Yaesu, Flex, and Elecraft radios, enabling automatic mode and frequency changes for ID transmission. It integrates with USB audio-capable radios like the Icom 7300 and Yaesu FT-991, simplifying connectivity with a single USB cable. The application features a fully programmable interface, adjustable CW speed from **5 to 35 WPM**, and ID intervals from **5 to 30 minutes**. The integrated "Pulse Tuner" function allows for safe amplifier and antenna tuner adjustments by sending short audio tones or rapid CW keying, with an adjustable duty cycle from 1% to 100%. It offers compatibility with a wide range of transceivers and amplifiers, and a schematic for a basic sound card interface is included for users without existing setups.

Commsaudit uk, i/q quadrature , hf receivers, rf, multicoupler, multicouplers, switch matrix, antenna matrices, masthead amplifier,, vhf receiver, uhf,

An HF 10-20m portable RF power amplifier based on the RD16HHF1 FETS giving 25 W.

A 200 Watt amplifier for 23 cm band

How to interface the Icom IC-7300 to RF Power amplifiers. Menu settings, cable connections and recommendations on how to avodi common errors that could even damage either the amplifier or the IC-7300

K9EID 75W power amplifier for the six meters

Linear amplifiers cold adjustments with network analyser (VNA)

A collection of audio amplifier projects by N1HFX

Home Brew 6 Meter Amplifier with a single 4CX250B by W4NFR

A synthesized 2.3 GHz Amateur Television (ATV) transmitter design, conceived by Ian G6TVJ, is presented, targeting broadcast-quality video performance on the 13cm band and extending up to 2.6 GHz. The core of the design utilizes a commercial Z-comm Voltage Controlled Oscillator (VCO) that tunes from 2.2-2.7 GHz, providing a +10 dBm output and simplifying RF alignment. This VCO's stability, originally intended for narrowband applications, readily accepts high-frequency video modulation, contributing to the transmitter's robust performance. The exciter stage, incorporating a Mini Circuits VNA 25 MMIC amplifier, boosts the signal to +16dBm, while a Plessey SP4982 prescaler divides the output frequency for the synthesizer. The synthesizer employs a Motorola MC145151 CMOS parallel IC, favored over the common Plessey SP5060 for its superior video modulation characteristics and ease of programming without microprocessors. This choice addresses issues like LF tilt and distorted field syncs often seen with SP5060 designs, particularly when operating through repeaters or over long distances. The MC145151 divides the signal further, enabling precise frequency stepping, with programming handled by EPROMs for channel selection and LED display. The loop filter network, critical for video integrity, was developed through experimentation to prevent the PLL from reacting to video modulation, ensuring a clean transmitted picture. The transmitter incorporates a Down East Microwave commercial power amplifier module, delivering approximately 1.6W output, driven by the exciter through a 3dB attenuator. Construction involves surface-mount SHF components on micro-strip lines etched onto double-sided fiberglass board, housed within a tinplate box. The design boasts no AC coupling in the video path, preserving low-frequency response, a common failing in other ATV transmitters. Performance tests with a 50Hz square wave revealed no LF distortion, and a calibrated "Pulse & Bar" signal showed a near 100% HF response, demonstrating its capability for high-quality ATV transmissions.

A nice review of the Acom 1000 HF and 6 meter RFpower amplifier by Acom in Dutch and with online google translation available. Includes pictures and notes of the popular amplifier by Acom.

1KW 70cm LDMOS amplifier project

Amateur radio products,wire and yagi antennas, SDR Receivers, upconverters, pre-amplifiers, towers and RTL funcube dongles by CT1FFU

Amplifiers, filters, attenuators, mixers, PLL, switches and frequency dividers, signal generators, power detectors, transimpedance amplifiers, variable gain amplifiers and more

Technical specifications and details of the Yaesu FL-2100B HF Power Amplifier

80 watt multi-mode amplifier using one of the newer S-AV36 Toshiba modules. Less than 50 milliwatts will drive it to full output in any mode.

Pictures of a homemade monoband linear amplifier for 160m band powered by 3 x QB5/1750

ON6MU 12 Watt amplifier schematic

While intended mainly for antenna loading coils, this article also applies to other resonant systems, such as amplifier tank circuits.

R3KBO is an amateur radio club producing and developing amateur radio kits and assembled products including HF VHF Power Amplifiers or RF Power Kits and amplifier parts, low pass filfers, band pass filters, sourge protections, splitters and combiners, antenna switches

eHam reviews of the Ameritron AL-811H HF power amplifiers

The problem originates by improper TXOUT-to-RF timing (RF transmission exists still after a TX-EN prohibition), combined by too long decay of their CW pulses.

Nuand id the maker of bladeRF - the USB 3.0 Superspeed Software Defined Radio, 300MHz - 3.8GHz RF frequency range Independent RX/TX 12-bit 40MSPS quadrature sampling

A 144MHz FM class C RF Power Amplifier based on a 2N6084 RF transistor, that can produce 50w output max

A very informative review of the Icom IC-7300 direct RF sampling transceiver, including audio samples, recordings and a comparison vs the Elecraft KX3

Demonstrates the complete design and development process for a **Low Noise Microwave Amplifier** (LNA), beginning with conceptual design and progressing through prototyping. The tutorial series covers the initial stages of a single-ended first gain stage, focusing on critical parameters such as noise figure, gain, and stability. It systematically details the theoretical underpinnings and practical considerations for achieving optimal performance in microwave frequency applications. This resource provides a structured approach to LNA construction, enabling radio amateurs and RF engineers to understand the iterative steps involved in realizing high-performance receive-side amplification. It offers insights into component selection, impedance matching networks, and the measurement techniques required to validate design specifications, particularly for **microwave** band operation where noise performance is paramount.

The AT-AUTO automatic antenna tuner handles 1.5kW CW operation, employing stepper motors under microprocessor control to precisely position a roller inductor and air-dielectric variable capacitor, avoiding relay-switched discrete components. This design choice prevents loud relay clacking and burning contacts, a common issue with competing products. The tuner features auto-retuning capabilities and receives periodic firmware updates, ensuring continuous improvement and added user-requested features. Its companion product, the _CX-AUTO_ coaxial switch, also features an embedded microprocessor controller. It enables selection of 1-of-8 coaxial outputs via a serial data interface. When integrated with the _AT-AUTO_, the tuner can associate specific coaxial outputs with amateur radio bands, automatically commanding the _CX-AUTO_ to select the correct antenna when the operator QSYs to a different band. Don Kessler began designing the AT-AUTO in 2005, with its debut at the 2006 Dayton Hamvention. Kessler Engineering also offers custom RF product design and electrical engineering consulting, specializing in Class-E RF amplifiers.

An home made low noise preamplifier project for 144 MHz, with detailed circuit diagram. The VLNA-144 preamplifier has been Published on DUBUS 4 2019

A home made project for an ATV RF power amplifier