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Topic regarding a new 1KW HF power amplifier with 2x GI7B -
This resource, "Transistor Audio Preamplifier Circuits," offers comprehensive design guidelines for constructing **bipolar transistor** audio preamplifiers. It delves into critical aspects such as quiescent current setting, voltage gain calculation, and the impact of various component choices on circuit performance. The content provides several _schematic diagrams_ illustrating different preamplifier configurations, including single-stage common emitter and two-stage designs, alongside explanations of their operational characteristics and practical implementation considerations. The analysis extends to frequency response, noise performance, and distortion, providing insights into optimizing these parameters for specific audio applications. The resource presents calculated gain figures for various stages, demonstrating how to achieve desired amplification levels. It also discusses the importance of proper power supply decoupling and input/output impedance matching, crucial for integrating these preamplifiers into larger audio systems or ham radio transceivers. The practical application of these designs is evident in their suitability for microphone preamplifiers or general-purpose audio amplification. -
Some unarranged docs about yaesu VX-5R, including EVE software. -
Over 15 years of experience in DXing and contesting informed the development of _DXHeat_, a responsive web DX Cluster and analytics platform. This service delivers real-time DX spots, accessible on both desktop and mobile devices, featuring intuitive filtering capabilities. Users can quickly narrow down spots by band, mode, or specific callsign, streamlining the search for rare DX or contest multipliers. The platform integrates data from various sources, including traditional telnet clusters, the Reverse Beacon Network (_RBN_), and _PSK Reporter_, offering a comprehensive view of propagation and activity. Beyond live spotting, DXHeat provides extensive cluster analytics for individual callsigns, allowing operators to research past activity and propagation trends. This deep dive into historical data can be particularly useful for planning future DXpeditions or optimizing contest strategies. The interface is designed for serious DXers, prioritizing quick access to relevant information and robust data analysis. -
Power supplies, rf power amplifiers, dummy loads, frequency counters, repeaters antennas manufacturer based in Italy -
Ham Radio online store dealer for Yaesu Kenwood Icom LDG Microham and many more ham radio related brands, based in Holland -
The **HFRadioSales.au** resource provides a commercial outlet for amateur and commercial radio operators seeking HF SSB equipment and related services. It focuses on the Australian market, offering new and refurbished transceivers, antennas, tuners, and a wide array of spare parts for brands like Codan, Barrett, and Qmac. The site details its role as a licensed dealer for new Barrett Communications and Codan radio and antenna systems, including specific models such as the Barrett 4050, 2050, and 950, and Codan Envoy and NGT series. This platform supports various applications, including vehicle, 4WD, outback, marine, and base station setups, catering to networks like HF Radio Club, VKS737, and RFDS. It also features commercial-grade antennas from Bushcomm, such as the BBA100C and SWC100, available for fast shipping from their Queensland warehouse. The site includes an FAQ section with general information on mobile HF communications in Australia and timelines for specific transceiver models. -
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Fractal Quad Yagi Antenna by KF7BS published on 73 magazine October 99 -
Whether we are tuning up homebrew equipment, checking antenna VSWR, adjusting a linear amplifier, or just monitoring output power during a contest, almost all aspects of ham operation can use a power meter. Paul Wade W1GHZ -
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Based on original G2BCX design this J-Pole antenna for the six meter band is made with a homemade ribbon cable. The antenna shown in this article includes a coaxial cable choke feed to remove RF currents from flowing on the outer of the cable. -
IK1PML Tipolitografia Bevione QSL Printer in Italy -
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HF Weather Fax lets you receive marine weather radiofascimile transmissions on your iPad, iPhone and iPod Touch. Just connect it to a shortwave radio tune in a weather fax frequency, and watch the images come in. -
Quad and loop antennas comparisons, evaluating the impedance and gain of both antennas and considerationso n horizontal loop antennas for low bands by PA0FRI -
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Antan is a homemade antenna analyzer project by F6BQU -
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HM-151 microphone shipped with the IC-7000 has inadequate audio output level -
Serving Tarrant, Parker, Wise counties, and city of Fort Worth, Azle, Springtown, Boyd, Weatherford, Saginaw -
Arduino uno universal VFO/BFO with Si5351 and TFT touch screen for BITX like txcvr -
Propagation forecasting software for the Macintosh -
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An Eprom Eraser with UV-Ray for 27Cxx Eprom (and similar, common in TNC) with a timer -
Picture and specifications -
Demonstrates the design and construction of a compact, portable multi-band mini-delta loop antenna, specifically optimized for /P (portable) operations from remote locations like Scottish islands. The resource covers the theoretical underpinnings of half-wave loops, contrasting closed and open configurations, and then details the application of a folded dipole principle to achieve a 50-ohm match for direct coax feed. It presents empirical formulas for calculating element lengths, considering the velocity factor of common wire types, and provides a detailed example for a 20m (14.175 MHz) version. The article includes a comprehensive table of dimensions and allowances for a five-band (20m, 17m, 15m, 12m, 10m) mini-delta beam, along with construction hints for the central support and balun. It specifies a 1:1 trifilar balun wound on a ferrite rod and describes the antenna adjustment process using an _MFJ-259B Antenna Analyser_. Initial test results indicate an SWR of 1:1 at resonance and a bandwidth of approximately 240 kHz on 20m, even at a low height of five feet above ground. The distinctive utility lies in its focus on a practical, easily deployable beam antenna for portable DXing, offering a viable alternative to more complex or larger arrays. -
Will we ever be able to dispel the myths? Steve Katz, WB2WIK/6 -
The array consists of 7 vertical antennas arranged as 6 verticals in a hexagon shape plus 1 additional vertical in the center of the hexagon -
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Huge amount of relevant information you should know before building a tower -
List of modifications for the kenwood TS-50 -
Converting a ZETAGI B303 power amplifier for 50 MHz usage -
This grid locator map uses Google map apis to find your QTH locator by simply clicking on the map. You can either enter your QTH locator and find the calculated distance and bearing between your QTH and another grid square. -
The Japanese Amateur Radio Teleprinter Society (JARTS) serves as a central hub for RTTY and PSK31 enthusiasts in Japan, providing essential information regarding its annual JARTS RTTY Contest. The resource outlines contest rules, exchange parameters, and scoring specifics, enabling participants to prepare effectively for the event. It also offers insights into the club's broader activities and its role in promoting digital mode operations within the amateur radio community. The site details the contest's operational periods and categories, which typically include single-operator, multi-operator, and SWL entries, often with power output classifications. Participants can find guidelines for log submission and result publication, ensuring adherence to the contest's administrative requirements. The JARTS RTTY Contest is a significant event for digital mode operators, drawing participation from across Asia and beyond. Beyond contest specifics, the resource provides historical context for JARTS, highlighting its foundational role in Japanese amateur radio digital communications. It serves as a primary point of contact for members and prospective participants, fostering engagement in RTTY and PSK31 modes. -
An Attic version for limited space applications by NW9T -
Website dedicated to Coastal Radio Stations, includes frequency lists for memdium frequencies maritime stations -
How to Increase your CW speed article by George Allison, K1IG as published on QST -
Small & practical DIY inverted U antenna. This design worked very well during the 2017 CQWW 160M SSB contest. -
Two modes of propagation at 50MHz E-layer & Sporadic-E by Ken G4IGO -
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Free programming software for the Wouxun KG-UVD1P, KG-UV2D, and similar radios. -
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A simple accurate power splitter for the 70cm uplink to Oscar 13 -
GW4ALG's _136 kHz Pages_ document the evolution of vertical antennas for the 2200m band, starting with a prototype mounted on a house wall. This initial design, despite achieving the first **395 km** GM-GW QSO, suffered from significant insulation breakdown, high RF losses due to proximity to the house, and difficult tuning adjustments. The author details the challenges of maintaining resonance and matching with a variometer in the loft, noting that adding three earth spikes offered no measurable improvement over a simple water tap connection. The subsequent experimental 12m vertical, relocated away from the house, significantly reduced dielectric losses and proved far more effective. This antenna enabled GW4ALG to set a world DX record on 136 kHz with a **1916 km** QSO to OH1TN, and an intra-UK record of **703 km** to GM3YXM/P. The resource further explores the use of helium-filled balloons to extend the vertical radiator, achieving heights up to 27m, typically 20m, for enhanced low-band performance. Practical advice on balloon types, inflation, and critical insulation between the wire and balloon is provided, emphasizing safety and avoiding arcing. -
Electronically controlled HF antennas. General coverage. Top features on all ham bands. Very advanced materials and state of the art technology.