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

Sommerkamp FT 250 Shortwave Transceiver (YAESU FT 200)

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

Information about RF driven lamps

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

The Mobileer group is for California Amateur Radio (Ham) operators to discuss family mobile radio caravan and camping trips.

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

This online project guide details the construction of a homebrew boom microphone system. It details the assembly of a microphone shell from a 3/4" PVC pipe section and an end cap, requiring a drilled hole for a snug fit of the electret or condenser mic element. The internal wiring schematic specifies a **2.2 K** resistor and a **47 uF** polar capacitor for signal conditioning, with a circuit diagram provided for integration with IC-706 series transceivers. The guide outlines the use of CAT-5 cable for internal connections, incorporating strain relief at the rear of the mic shell, and an inline 3.5 mm jack to facilitate an external _PTT_ line, designed for a foot-mounted switch. Further construction involves fabricating a microphone shock mount from a 2-inch PVC connector, detailing the creation of four "fingers" and the insertion of screw-eyes for attaching elastic bands, which are twisted 180 degrees for tensioning and vibration isolation. A foam wind screen is also incorporated into the microphone assembly, secured with adhesive. The boom arm itself is repurposed from an articulated architect lamp, with the original lamp assembly converted into a **60 watt** resistive load for testing power sources. Microphone cabling is secured to the boom arm using wire ties, ensuring sufficient slack at hinge points to maintain articulation. The boom base is mounted to a bookshelf, requiring specific positioning to achieve proper microphone placement in front of the operator. Performance evaluation of the microphone system is conducted through on-air audio signal reports from other amateur radio operators. DXZone Focus: Online Project Guide | Boom Microphone Construction | Electret Mic Element | PTT Line

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.

Located in the northeastern corner of New York State Between the shores of Lake Champlain and the foot hills of the Adirondacks

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.

The SETI League, Inc., founded in 1994, focused on participatory science, developing technology to seek definitive answers to the question of extraterrestrial intelligence. The organization operated in five dozen countries across all seven continents, maintaining the quest for cosmic companions through the efforts of its 1500 members. Although the organization shuttered its virtual doors after thirty years in 2024, the website remains for educational and historical purposes, documenting past research and activities. Key technical resources include the _SETI League Mini-Manual_ for constructing a 12 GHz radio telescope under $200, and software like _SETIFox for Windows_ and _Radio Eyes_ for radio astronomy sky viewing. The site also features _Project Argus_ detections, moonbounce signal detections, and space probe signal detections, providing concrete examples of amateur radio astronomy applications. Publications such as the quarterly newsletter _SearchLites_ and various articles by Dr. SETI (H. Paul Shuch, Ph.D.) are available, alongside information on the Third Penn State SETI Symposium in 2025. The site also offers insights into hydrogen line emission observations, presented in time domain, frequency domain, waterfall, and surface plot formats.

715 days, 6 hours, 58 minutes, and 29 seconds of uptime are reported for the YSFReflector-Dashboard by DG9VH, which monitors the IT C4FM SUD / ITALY-SUD reflector. This dashboard, compiled on December 1, 2017, provides real-time operational statistics for the reflector, including system information, disk usage, and connected YSFGateways. The dashboard also features a "Last Heard List" and an "All Heard List," displaying callsigns, durations, and timestamps (Europe/Rome) of stations active on the reflector. These lists offer a quick overview of recent activity, which can be useful for tracking **C4FM** traffic. While the resource is titled "IZ7AUH-6 DX Web Cluster," the primary content displayed is a **YSFReflector** dashboard. This suggests the platform might serve a dual purpose, offering both traditional DX cluster services and monitoring for Yaesu System Fusion reflectors.

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

QSL Printer shop, products include Photo QSL cards, Eyeball cards, and State QSL Cards, based in Hampstead, MD USA

Common causes of failues, due to wrong clamps. About Guy Anchors

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

A 200 Watt amplifier for 23 cm band

This is multi multi radio amateur contest station oh2u which have won three european champions

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 simple, cheap and easy to build 26 feet long vertical antenna that works DX on 20 - 10 meters including WARC Bands, it is designed for portability for field days, camping, or permanent installation, cost, and to achieve at least 1/2 wavelength on the WARC bands.

Solar activity can aid or hamper HF propagation beyond line-of-sight range, WA1SVF and N6BV answers to questions about Sun influence on radio signals propagation

A collection of audio amplifier projects by N1HFX

160-10 Meters 1500 Watt Amp - W4NFR

A postage-stamp-sized DSP microcontroller imbedded in the TNC-X eliminates the dedicated laptop or PC.

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

G0KYA MMANA-GAL presentation and samples

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.

D.I.C. Diploma Isole Campane from Italy

Windows program to divide one big ADIF file to many shorter ADIF files, based on qso numers, in example to send it to LoTW.

Servicing the University Park campus of The Pennsylvania State University, and the Penn State Amateur Radio Club.

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.

Storm Products Company provides high-value, interconnect products, subsystems, and services to electronics, communications, and instrumentation markets worldwide. Products include Electronic and Microwave cable assemblies, components, and test products.

1KW 70cm LDMOS amplifier project

Wideband receiving phased arrays with small electric or magnetic active wideband elements are discussed in details. Practical results and examples are given.

Sommerkamp FTDX500 - Yaesu FTDX400 restoration

Improving the reception on 70 MHz for the yaesu FT-847

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

2009 IARU HF World Championship Contest Rules

Yaesu FL-110 160-10m HF linear ampflifier as ideal power amp for the FT-817 by N2CHK