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This resource details the computer-optimized design of the _ZS6BKW_ multiband dipole, an evolution of the classic _G5RV_ antenna. It begins by referencing the original 1958 RSGB Bulletin article by Louis Varney G5RV, explaining the operational principles of the G5RV's flat-top and open-wire feedline on 20m and 40m, noting its impedance transformation characteristics for valve amplifiers of that era. The article then transitions to the rationale for optimizing the design for contemporary solid-state transceivers requiring a 50 Ohm match. The core of the project involves using computer modeling to determine optimal lengths for the flat-top and matching section, aiming for a VSWR of less than 2:1 on multiple HF bands. It discusses the process of calculating feedpoint impedance based on antenna length and frequency, referencing professional literature from Professor R.W.P. King at Harvard University. The analysis also considers the characteristic impedance (Z(O)) of the open-wire line, identifying a broad peak of adequate values between 275 and 400 Ohms. Specific design parameters for the improved ZS6BKW are presented, including a shorter flat-top and a longer matching section compared to the original G5RV, with a velocity factor of 0.85 for the 300 Ohm tape. The article confirms acceptable matches on 7, 14, 18, 24, and 28 MHz bands when erected horizontally at 13m, and also discusses performance in an inverted-V configuration, noting frequency shifts. The author, Brian Austin ZS6BKW, emphasizes the antenna's suitability for modern 50 Ohm coaxial cable without a balun. -
Overview, summary, tutorial about the log periodic antenna or aerial used for wideband RF antenna applications -
Simple implementation of the ARRL Antenna Book design equations for the axial-mode helical antenna. -
TH F6A service menu, On TH-F6 transceiver, the Service Menu is accessible only by opening the transceiver -
F5RDH project of a transverter, that can receive input in HF and convert output to 144 Mhz in french -
Midland GXT-900 FRS/GMRS 30-Mile Range Two-Way Radio product review -
IC-2100H mods by ham.dmz.ro -
LogView is a free post-contest log-visualisation tool, for analysing contest performance. It plots the QSOs in a Cabrillo-format contest-log on to one of 8 different maps by finding the position of each QSO from an online database of about 970,000 W/VE callsigns. -
MMMonVHF maintains the data for 6m, 2m, 70cm and 23cm bands in collaboration to LA0BY. This site allow display of a beacon map and latest beacon spots. -
Display solar activity forecast for next 27 days, display A-index, Sunspot Numbers and Flux forecast including graphs for solar activity and geomagnetic forecast. All forecasts are updated daily. -
The TU2T DXpedition log provides a critical resource for verifying contacts made during the 2011 operation from _Ivory Coast_. This online tool allows operators to quickly confirm their QSOs, which is essential for QSLing and award applications. Users can typically search by callsign, date, or band to locate specific entries, ensuring accuracy for their personal logbooks. Such online logs are indispensable for DXers pursuing awards like **DXCC**, as they offer immediate confirmation of rare or distant contacts. The ability to verify a QSO without waiting for a physical QSL card significantly streamlines the award application process. This particular log facilitates the confirmation of contacts with the TU2T operation, a highly sought-after entity. -
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Morse Tutor is a DOS based program written in C++. It can be used to practice morse code. Various options are available. Morse tutor with Complete Source Code and Binary is available for Download (32KB). -
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yaesu radios community talk, impressions and comments about yaesu vx7r -
Win-EQF provides a comprehensive logging solution for amateur radio operators, integrating station control and DX resource management within a single application. It supports various operating modes and offers features for efficient logbook management, essential for contesters and DXers alike. The software is designed to streamline the process of recording contacts and managing station operations, which is crucial for achieving awards like **DXCC** or **WAZ**. Operators can utilize Win-EQF to maintain detailed records of their QSOs, track award progress, and interface with other station hardware. Its robust logging capabilities ensure accurate data capture for every contact, from basic information to specific contest exchanges. The program also facilitates the use of external DX resources, helping operators identify and pursue rare DX entities. This tool is particularly useful for those seeking to optimize their station workflow and enhance their overall operating experience. -
A project to build a cross band repeater using a pair of Baofeng UV5R handheld transceivers. -
The U.S. Amateur Radio Callsign Lookup service, hosted by the University of Arkansas at Little Rock (UALR), offers a direct interface for querying the FCC's amateur radio license database. This resource is specifically designed for rapid retrieval of licensee information, including callsign, name, address, license class, and expiration date, all critical data points for QSLing and contact verification. The underlying database is refreshed daily, ensuring that the presented information reflects the most current FCC licensing records available. This service distinguishes itself by its direct reliance on official FCC data, processed and maintained by a university institution, which lends a degree of authoritative accuracy to its lookups. Users can input a specific callsign to instantly access detailed license particulars, facilitating efficient station identification and record-keeping for DXers and contesters alike. The daily update cycle minimizes discrepancies often found in less frequently synchronized callbook services. The UALR callsign lookup functions as a straightforward, no-frills utility, prioritizing data integrity and accessibility for the amateur radio community. Its operational simplicity and consistent data refresh schedule make it a reliable reference for verifying U.S. amateur radio licenses. -
RemAud is a Voice over IP (VoIP) application primarily designed for two-way amateur radio remote control over the Internet. RemAud uses streaming-audio technology in a client-server architecture. It features high radio sound quality, low latency, low bandwidth and very low CPU usage by DF3CB -
This online tool will convert any street address into latitude and longitude and vice-versa by executing queries to several online mapping services like googlemap geocoder maporama terraserver and more by Stephen P. Morse -
DF3CB site, contesting, and software BV is a professional freeware software for the QSL Management and Label/QSL Printing under Windows developed and distributed by Bernd Koch, DF3CB, since 1989. It is mainly designed for the contester and QSL manager with high QSL quantities but useful for all other QSL'ing purposes as well. Includes logging features -
Are you experiencing very high SWR with the 10M Modification to Ameritron AL-811 amplifier ? This is a good forum topic to fix this problem. -
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This database contains data on thousands of tubes -
IC-2720H modifications and links to manuals -
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A vertical antenna specifically designed to work with the 80 meter CW beacon keyer -
The ICOM 746-Pro has acquired a history of NEC 1678G (IC-151) MMIC and driver transistor 2SK2975 failures. The failure of IC-151 appears to be a combination of ESD damage from electrostatic charge on the antenna entering IC-151, and perhaps thermal heat. -
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The 60 Watt linear amplifier is simple all solid state circuit using power mosfet IRF840. -
A vertical antenna project than can present low swr from 40 to 10 meters by using a balun in french -
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A simple online folded dipole antenna calculator -
Remotely controlled antenna switch that can switch between 5 antennas -
Calculate design for a quadrifilar helicoidal antenna -
This free program by SP7DQR is designed to print QSL Cards using Mail Merge Tool in MS Word from ADIF file. -
Online log for 5V7TT Togo dxpedition 2010. Offer QSL request service. -
MSDOS astronomical clock and celestial tracking program with navigation features -
The page provides a utility to record QSOs for amateur radio operators, allowing them to send the recorded signal back to the other station. It addresses challenges with VOX capability in radios and offers solutions for different radio models. -
Mods and informations about yaesu VX-5R -
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Online helix antenna designer, calculate size of helix antennas online -
Enables users to convert plain text into _Morse Code_ and, conversely, decode Morse sequences back into readable text. This web-based utility provides a straightforward interface for rapid translation, proving useful for both learning and practical application. It processes input efficiently, displaying the corresponding Morse or text output instantly. Operators can leverage this tool for generating practice copy or for deciphering received CW signals, making it a handy resource for those honing their code skills. The translator handles various character inputs, converting them into standard International Morse Code elements. This simple utility supports quick lookups and real-time conversions, facilitating a better understanding of CW structure and timing. It operates entirely online, requiring no software installation. -
Discussion on how properly drive and tune athe Ameritron AL-811 power amplifier -
A solid state linear based on EB104 Motorola Engineering Bulletin by Helge Granberg. It uses 4 MRF150 FETs in push-pull parallel to acheive 600 Watts from about 6 Watts drive -
Tuning the Solarcon Antron A-99 antenna for 20 meters band -
A project of a vertical and wires that generate a multiband antenna for 28 14 10 and 7 Mhz in french -
Info about Yaesu VX-8R by APRS Wiki -
