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Freeware windows RTTY PSK31 software decoder that allow logging, award tracking and qsl printing. By SQ1FTB

Online calculator for Cantenna special antenna for 802.11 Wi-Fi bands

Lets you automatically record your favorite radio programs from Web Radio broadcasts, and then listen to them later on your PC, MP3 player or Pocket PC.

Forum thread about possibility to extend VX-6R to freeband and 6 meters

A small antenna for all amateur bands, including 80 meters, and in a small garden without the compromise. An ideal replacement for those half size antennas such as the 1/2 size G5RV and Windom 40

Home made bazooka antenna for 2 meters band

Search for call sign and display maps and dxcc info

Calculate dimension for discone antennas online

IC 706 modifications collected by mods.dk

KGKSDR is my attempt at some SDR decoding software. I'm putting this software together purely as a learning exercise, to better understand the mathematics behind SDR in general.

A list of all IOTA reference numbers and IOTA groups for the Islands On The Air award, personalised to your own QTH

The Voice Keyer is a free Windows based voice keyer. It is very easy to use and it handles up to seven messages. By connecting your computer soundcard to your radio it's possible to just press a button and the computer will CQ for you, to spare your voice. It can also PTT your radio via the LPT port by SM3WMV

Modifications for Icom IC-2100H by mods.dk

Official IARU Region 1 band plan

Write down grid squares of your QSOs and this nice online tool will create a World map with all contacts QTH linked to your home QTH. The QSO map picture can be downloaded for resharing.

An online audio signal generator application capable to reproduce different waveforms with variable frequency range

Search the online log of VP8PJ DX pedition to South Orkney Feb. 21, 2020 - Mar. 6, 2020 Log search offered by M0URX.

Calculate dimension for HB9CV directional antennas

VX-5R Loose antenna cure, Vx-5r Free Band, VX 5 R modification for German, VX-5R expanded frequency mod, VX-5R MARS/CAP & freeband mod

Calculates precise dimensions for **Moxon rectangle** HF antennas, enabling hams to design antennas by inputting desired resonant frequency and wire diameter. This web-based tool, version 0.5, is a PHP front-end developed by W4/VP9KF, based on a public domain BASIC program originally authored by L. B. Cebik, W4RNL. It generates critical measurements for the driven element and reflector, ensuring proper spacing and element lengths for optimal performance. User feedback confirms the calculator's accuracy, with one user reporting resonance within 50 Hz of the design frequency for an 18 MHz antenna, eliminating the need for SWR adjustments. This contrasts with other online tools that resulted in significant frequency discrepancies. The tool's precision facilitates building **directional antennas** for specific bands, contributing to effective DXing and contesting operations.

The PIC-MORSE is an electronic iambic keyer, integrating a generator of Morse code and a sidetone. It is built with a microcontroller PIC16C711. In French

Ideal for QRP operations on 10 meters band in french

Software for radiomonitoring, radio spectrum analysis. MDS is designed for the real time radio spectrum analysis. It performs real time activity analysis, signal search and collects spectrum data for post time analysis.

Constructing a compact UHF Moxon antenna for portable radio or TV applications demands a small, easily transportable aerial. This project focuses on a straightforward build method rather than a specific frequency design, leveraging _MoxGen_ software by AC6LA to derive precise dimensions. The author's approach utilizes an epoxy printed circuit board as the support, with traces drawn by a special felt-tip pen for soldering the antenna elements after an etching bath. For high-frequency work, particularly in the GHz range, the choice of insulating material is critical; the article emphasizes the necessity of quality UHF or SHF-grade insulation. A standard SMA connector is integrated, with one element making electrical contact via the nut and the other soldered to the central pin. This ensures a robust feedpoint for the coaxial cable. The coaxial cable, fitted with its connector, is threaded through a 12mm PVC tube that functions as a mini-mast. This tube also defines the antenna's forward direction, which should be aimed at the target signal. A sanitary clamp at the base of the tube secures it to a photographic tripod via its 7mm thread, providing a stable and portable mounting solution.

This page is a short description of the four phased verticals system i've build and used. It is primarily intendend to be used on the lower bands 160m, 80m, 40m.

Overview, summary, tutorial about the dipole antenna or dipole aerial that is widely used on its own and as the basis for other antenna designs.

List of italian airport frequencies

Modifications collected by mods.dk

Click on the map and the QTH locator will be calculated

A 46ft multi-band antenna for small gardens that works on 80m. An excellent DX performer and is an ideal replacement for your half size G5RV by G7FEK

A project for a portable antenna for amateur radio satellite reception, for 2 meters and 70 centimeters bands

G4URH calculations to design your own antennas, ground plane, half wave antennas, Quad Antennas and 5/8 verticals

modifications collected about Yaesu VX-150 by mods.dk

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.

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

Overview, summary, tutorial about the log periodic antenna or aerial used for wideband RF antenna applications

Yaesu VX-6R mods

Simple implementation of the ARRL Antenna Book design equations for the axial-mode helical antenna.

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

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.

Online Yagi Uda antenna calculator

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).

Mods for the yaesu FT-950

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