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L4B by Drake amplifier mod

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

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

A 200 Watt amplifier for 23 cm band

A collection of audio amplifier projects by N1HFX

K9EID 75W power amplifier for the six meters

Linear amplifiers cold adjustments with network analyser (VNA)

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.

A page dedicated to Yaesu FL series RF Amplifiers, from FL-2100 to FL-2000 FL-2500 FL-1000

1KW 70cm LDMOS amplifier project

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

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

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

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.

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

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

ON6MU 12 Watt amplifier schematic

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

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.

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.

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.

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

ACOM 1000 160-6m amplifier specifications and features

ATV products manufacturer, antennas, ATV transmitters, SWR meters, amplifiers

Article describes a circuit that accelerates the coil of DC relays by momentarily doubling their voltage.

A home made project for an ATV RF power amplifier

222 MHz kilowatt linear amplifier

A forum thread about tuning with the Kenwood TL-922 TL-922A Power amplifier

Icom PW1 Linear Amplifier, setup and configuration PDF file

Matrix of several popular amplifiers currently on the market

European dealer for Ham Amplifier, amateur radio RF power amplifier by Zhong Xing

Measuring the output impedance (Zs) of solid-state broadband HF amplifiers operating in class AB eham article by ZS6BIM

Naptech buys and sells quality test equipment from hp, tektronix, including spectrum analyzers & peripherals, oscilloscope, frequency counters timers, signal generators, multimeters & voltmeters, RF & power meters, microwave amplifiers

Printer in Poland, now provide T-shirts, CAP with Call sign, dust cover for yaesu, icom, kenwood, elecraft transceivers, acom amplifiers and more. QSL printing has been dismissed

Modifications to an Ameritron ALS 600 power amplifier by AF6SA

Common problems of the 572B tubes often used in many RF Power Amplifiers

Selecting appropriate coaxial cable and wire for demanding amateur radio applications, particularly those involving high power or harsh environmental conditions, is crucial for maintaining signal integrity and operational safety. This resource details Harbour Industries' specialized offerings, which include Mil-Spec and commercial designs such as NEMA HP3/HP4 and SAE AS22759, suitable for aerospace, military, and industrial sectors. Their product line addresses the need for robust conductors capable of withstanding extreme temperatures and mechanical stress, often encountered in antenna systems or amplifier interconnections. The company highlights its AeroPOWER® Firezone M25038/3 cable, specifically engineered for high-temperature environments like aircraft engines. This particular product exemplifies their focus on solutions for critical infrastructure where reliability under adverse conditions is paramount. Such cables are relevant for hams building or maintaining stations in challenging climates or those operating high-power amplifiers where internal wiring must endure significant thermal loads. Harbour Industries also provides a range of high-performance cables designed to meet stringent specifications. Their expertise in high-temperature and high-performance cable manufacturing positions them as a supplier for specialized wiring needs beyond standard off-the-shelf options, ensuring durability and performance for advanced amateur radio setups.

Ham and Amateur Radio Swap - Buy, Sell, Trade, Swap, radios, amplifiers, antennas and more. Classified ads for Canada, Ontario, Quebec, Maritimes, Prairies, British Columbia and USA

Official product page of the 1452G RF Amplifier by TE Systems

The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a **LM34** temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise. This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a _TIP120 Darlington transistor_ to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments. Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.

A Bass Eq Pre amplifier for high impedance PU by ON6MU

There are a number of important technical issues relating to the matching of speakers to amplifiers, and to the wiring of multiple speaker systems

Article appeared on 10/05 issue of QEX about the impact of load SWR on the efficiency of Power Amplifiers, PDF File by K9LA

This amplifier uses two 60w Spectrian amplifier boards with the usual input and output hybrid coupler and combiner.

Schematic diagram for a high voltage power supply by W4NFR

This versatile broadband amplifier is used in several DX Lab projects.