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RF Concepts manufacturer of Alpha Linear Amplifiers, amateur radio RF power amplifiers, commercial power amplifiers, power meters and dummy loads.

Over 25,000 amplifiers and sub-assemblies were produced by Angle Linear for the communications industry over a 40-year period. The company specialized in **high-linearity RF products**, focusing on preamplifiers, bandpass filters, and receiver multicouplers. Specific product lines included PHEMT and GaAs FET preamplifiers, offering both quadrature and single-ended configurations for various signal levels. The offerings encompassed coaxial and combline bandpass filters, along with integrated filter-preamplifier assemblies. The company also provided custom RF assemblies, addressing applications such as MRI preamplifiers, passive radar, and EME (moon bounce). Their product range covered VHF and UHF frequencies, including specific designs for 2m, 70cm, and 23cm bands, often featuring high IP3 performance. Technical documentation, such as filtering application notes and duplexer theory, was also associated with their product offerings.

HF VHF UHF amplifiers, designed by hams for hams, and morse keys manufacturer

manufactures and distributes HF, VHF, UHF and SHF equipment covering 10MHz. - 47.0GHz. Our products include: Wireless LAN / WAN Bidirectional Linear Amplifiers, Low Noise Preamplifiers - LNA's, RF Linear Amplifiers, Relays, Transverter Systems, Frequency Translation Systems, Downconverters, Antennas, Parabolic Dishes, Coaxial Cable, Relays, Antenna Switches, Microwave Test equipment, PC controlled Receivers, Microwave Linear Amplifiers including models for Telemetry, Wireless, and CDMA applications.

Infomration schematics and pictures about various hf and vhf QRO linear amplifiers

Constructing a high-power solid-state amplifier for HF operations presents unique challenges, particularly when aiming for significant output like 600 watts. This project details an amplifier design employing **Motorola MRF150** FETs, a common choice for their robust performance in RF power applications. The design emphasizes achieving substantial power output, a critical factor for effective DXing and contesting, where every decibel can make a difference in signal propagation and readability. While specific circuit diagrams or construction details are not directly presented on the current page, the mention of MRF150 FETs points towards a design that would typically involve push-pull configurations, impedance matching networks, and robust power supply considerations to handle the high current demands. Such amplifiers are often built with an eye towards linearity and efficiency across the HF bands. Amateurs pursuing similar high-power solid-state projects often share insights on thermal management, intermodulation distortion, and component sourcing, all vital for a stable and reliable amplifier capable of delivering 600 watts into a proper antenna system.

I4FAF etrode Tube Linear Amplifier experience

The Discovery series of amplifiers are designed and built in the UK by Linear Amp UK Ltd, one of the world's leading amplifier manufacturers, specializing in high power RF tube amplifiers. The amplifiers use large GS31 or GS35 ceramic triode tubes. Band coverage 6m, 2m and 70 cms

Angle Linear has been producing GaAs FET preamplifiers since 1980

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

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

QST Magazine Product Reviews - Key Measurements Summary - HF-Transceivers or Receiver and Linear Amplifiers

Linear Amp UK specializes in the design and production of high-quality linear amplifiers, offering models for HF, VHF, and UHF amateur and commercial applications. The company emphasizes nearly 30 years of experience in crafting each unit, ensuring robust performance and longevity. Their product line includes amplifiers engineered for a 100% duty cycle, promoting continuous and reliable operation across various modes. The amplifiers feature solid, dependable designs, ensuring quiet and effortless performance during transmission. Each unit is hand-built to stringent standards, reflecting a commitment to durability and operational stability. All products are CE approved, confirming compliance with European safety and environmental directives, and come with a standard two-year warranty, providing assurance to operators. Key specifications often include coverage for 1.8-30MHz (WARC bands), 50MHz, 70MHz, and 144MHz, utilizing tubes such as 811, 572, 811A, 572B, GS35, GS35B, 8877, 3CX1500, and _3CX1500A7_ in their designs.

Understanding Solid State Linear Amplifiers

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

Linear amplifiers cold adjustments with network analyser (VNA)

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.

RF amplifier products from NP Technologies, Inc. encompass a wide array of specialized designs, including highly linear Class A broadband amplifiers, crucial for maintaining signal integrity across various frequencies. Their portfolio also features cell band amplifiers, specifically engineered for cellular communication infrastructure, and pulse amplifiers, which are vital in applications requiring high-power, short-duration signal bursts. The company's manufacturing capabilities extend to AM and FM broadcast amplifiers, supporting radio transmission systems, and military VHF amplifiers, designed to meet rigorous defense specifications for robust and reliable communications. NP Technologies, Inc. emphasizes comprehensive development, design, manufacturing, and testing processes for all its RF amplifier offerings. This integrated approach ensures that each product, from initial concept to final deployment, adheres to stringent performance and reliability standards. The company's expertise in these areas allows for the creation of custom solutions tailored to specific client requirements, addressing complex RF challenges in diverse operational environments. Their product range demonstrates a commitment to serving multiple sectors, including commercial broadcasting, telecommunications, and defense. The focus on specialized amplifier types underscores their technical depth in RF engineering.

Not a project yet, but very theoretical thoughts about very practical amplifiers!

The MiniPA Linear Amplifier for HF page discusses the popularity of QRP for HF among ham radio operators, such as those using the Yaesu FT818 or low power SDR transceivers. It explores the use of cheap kits from eBay or Chinese suppliers to build a 70-100W SSB amplifier using IRF530 MOSFET transistors. The article provides a review of the MiniPA design, including its features, components, and assembly process. It also highlights the importance of using a heatsink and forced air cooling for optimal performance. This page is useful for hams looking to enhance their HF rig with a budget-friendly amplifier.

The Olivia digital mode, a **Multi-Frequency Shift Keying (MFSK)** radioteletype protocol, is specifically engineered for robust communication under difficult propagation conditions on shortwave radio bands from 3 MHz to 30 MHz. Developed by Pawel Jalocha in 2003, Olivia signals can be decoded even when the noise amplitude exceeds the digital signal by over ten times, making it highly effective for transmitting ASCII characters across noisy channels with significant fading and propagation phasing. Early on-the-air tests by Fred OH/DK4ZC and Les VK2DSG on the Europe-Australia 20-meter path demonstrated intercontinental contacts with as little as one-watt RF power under favorable conditions. Common Olivia modes are designated as X/Y, where X represents the number of tones and Y is the bandwidth in Hertz, with examples including 8/250, 16/500, and 32/1000. The resource clarifies that Olivia, unlike some other digital modes, produces a constant envelope, allowing RF power amplifiers to achieve greater conversion efficiencies and making it less prone to non-linearity. Operators are advised that **Automatic Level Control (ALC)** can be set higher than no meter movement for MFSK modulation, as long as it's not driven past its high limit, contrary to common misinformation about other digital modes. The Olivia community encourages voluntary channelization on suggested calling frequencies, such as 14.0725 MHz for 8/250, to facilitate initial contacts, especially for signals below the noise floor. The Olivia Digital DXers Club provides links to Groups.io, Facebook, and Discord for community engagement and offers details on QSO parties.