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FreeDV plus Video adds simultaneous digital voice (FreeDV) to ZL2AFP's OFDM TV (see OFDM TV page listed under Software/SSTV and FreeDV page listed under Software/Digital Voice). An older version of OFDM TV is used, modified for compatibility with FreeDV. The video is 1 frame/sec, 36-lines, with full color. Total bandwidth is 3.5 kHz.

Documents the OC1I and OC6I IOTA DXpeditions to Peru, specifically highlighting operations from SA-098 (Isla La Leona) and SA-076 (Isla Lobos de Afuera). The OC1I team logged over **8000 QSOs** from SA-076, while OC6I made 1400 QSOs from SA-098, despite challenging propagation conditions. The resource details the equipment used, including an _IC-7000_, an IC-706mkIIG, and a TS-440SAT, along with various antennas such as a 160m dipole, FD4, G5RV, and a multi-band vertical for 17m, 20m, 30m, and 40m. The DXpedition dates are specified: OC6I operated from SA-098 between December 28 and December 30, while OC1I was active from SA-076 from January 2 to January 7. Both operations are confirmed as valid for IOTA credit. The page also includes a video link for the OC6I operation and a photo gallery from the DXpedition. Feedback is welcomed, and the webmaster is identified as Bodo Fritsche, DL3OCH.

A summary, overview or tutorial covering the basics of Meteor Scatter or Meteor Burst Communications, a form of radio signal propagation often used at VHF.

Near Vertical Incidence Skywave propagation is a form of radio wave propagation used on the MF and HF bands to provide radio communications and broadcasting coverage over short distances, especially where the terrain contains obstacles.

Display your current Maidenhead locator with 10 digit precision. It also computes bearing and distance to a set of target locations using locator or latitude / longitude. Useful to align antennas in VHF / UHF / microwave DX activities. No network or fancy maps usage, so it can be used even in remote locations.

The basics of radio receiver dynamic range performance used for specifying the performance of radio receivers used in radio communications systems.

Abbreviations used in CW operation

Next Generation Beacon hardware platform encompasses both analog and digital modes, i.e. CW FSK and MGM in a mixed mode configuration. The advantage of the mixed mode is that humans can decode the CW FSK by ear and the MGM can be decoded by computers way below what is audible. Therefore the MGM can be used for pre-human-conditions or early warning monitoring.

This versatile broadband amplifier is used in several DX Lab projects.

Brugtgrej presents a Danish online classifieds platform specifically for amateur radio operators and electronics enthusiasts. The platform facilitates the buying and selling of used equipment, including transceivers like the Icom IC-7410, various components such as X'TAL FILTER FMT-15A and TRANSISTOR 2SC3019, and accessories like Sadelta microphone capsules and SMA to SMA extenders. Users can post free advertisements for items they wish to sell or acquire, covering categories beyond amateur radio, including antique radios, military radios, and radio tubes. The site lists active advertisements, with 3136 online ads and 167 online users at the time of analysis, indicating a dynamic marketplace. It also features a forum for community interaction, discussing topics like repeater rings on 1297 MHz and FT8 activity. The platform's structure supports both 'Sælges' (for sale) and 'Købes' (wanted) listings across its various sections. Specific items observed include a Miniwatt pentode 4689, various capacitors and coils, and general electronic components, demonstrating the breadth of offerings available to the amateur radio community.

Presents a personal blog, "QSL, maraca!", maintained by Luiz Belem, PY1UR, detailing his amateur radio endeavors. The content includes posts on station setup, operating experiences, and general ham radio topics, reflecting the perspective of an active DXer and contester. The blog serves as a digital logbook and platform for sharing insights with the amateur radio community. Documents PY1UR's participation in various on-air activities, showcasing his QSL card collection and providing narratives behind specific contacts. It offers practical insights into antenna configurations and radio equipment used, demonstrating effective strategies for achieving **DX contacts** and improving station performance. The blog's entries provide a historical record of PY1UR's _amateur radio journey_.

This resource is an online tutorial focused on setting up the Raspberry Pi for amateur radio applications. It covers the installation and configuration of various software packages tailored for digital communications and protocols, including _Packet Radio_ with Hamlib and Direwolf, as well as data modes like FLDigi and WSJT-X. The guide also details the integration of hardware components such as GPS clocks for time synchronization and real-time clocks for enhanced functionality. Users will find instructions for installing software like GPredict for satellite tracking and GQRX for software-defined radio (SDR) applications. The tutorial emphasizes practical steps, including the use of command-line inputs in the Raspberry Pi OS terminal, and provides troubleshooting tips for common issues such as faulty SD cards or insufficient power supplies. Operators are encouraged to explore various applications, including APRS iGates and WSPR beacons, to enhance their ham radio experience. The material is designed for licensed amateur radio operators with basic knowledge of electronics and computing.

A linear regulated power supply 2A, 20 V designed mainly to get used to soldering and have something usefull as final result.

The antenna almost repeat the design of the Car Antenna however instead of aluminum tubes it was used copper wire in plastic insulation in diameter of 2- mm (12 AWG).

There are many many abbreviations used for words on CW, ranging from commonly used abbreviations like B4 for Before or TU for Thank You to very obscure abbreviations known only to the one using them.

The details of the spark gap transmitter and its history: how it was invented, developed and used.

Article on propagation basics. The ground wave used for radio communications signal propagation on the long, and medium wave bands for local radio communications

PilotMORSE is a great home solution for private pilots or aspiring professionals who want to hone their Morse code skills used to identify VORTACs, localizers, and marker beacons. PilotMORSE takes you through the alphabet with an advanced neural network algorithm that adjusts the pace of presentation based on your responses.

An improved version of the audio interface commonly used to connect a computer soundcard to a transceiver\'s receive and transmit audio circuits

IC706_BKT CAT is used to control the transceiver Icom IC-706, IC-706MKII IC-706MKII/G and IC-718 from the personal computer. Works on Windows and is available in free and free donation version

The _Touch CPO_ circuit offers a unique method for Morse Code practice, eliminating the need for a physical key. It leverages the versatile IC555 timer, configured as an astable multivibrator, to generate an audio tone. Users can adjust the tone's frequency by manipulating a 100 K variable resistor connected between pins 7 and 6 of the IC555, providing flexibility in the practice experience. Volume control is achieved via a 10 K variable resistor, while a 1 K Ohms preset at pin 4 of the IC555 allows for fine-tuning the touch plate's sensitivity. The design connects the touch plate to the base of a BC147B transistor, a configuration noted for its flexibility regarding the length of wire between the transistor and the touch plate. The author's prototype successfully used a 9 cm wire with a 3 x 6 cm aluminum plate. This project also suggests an alternative application as a touch-operated doorbell, demonstrating the circuit's adaptability. The design emphasizes simplicity and ease of construction, making it accessible for hams interested in DIY electronics.

Wondering whether human body could be used as an antenna.

All the essentials about the Dip Meter or Grid Dip Oscillator used for many RF measurements including detecting resonance, locating RF emissions, and making many RF measurements.

An article by microHam about guidelined to eliminate problems caused by RFI

Electronic keyer by pressure sensor. SEN-09673 is used for detecting touch.

Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia.

Articles on the correct placement of ferrite noise suppressors are common, but little has been written about the different options and where to buy them. This page contains an interesting comparison of several ferrite types used to reduce RFI.

This circuit stores a morse code message as bits in an EPROM chip, the message controls a relay that keys a CW morse code transmitter. An Arduino processor can also be used in place of this circuit, that eliminates the need to build the circuit and program an EPROM.

A tutorial on how to setup a receiver capable to decode SSTV signals with a small RaspberryPi version 2 and a RTL-SDR dongle. The author explains how to install the needed software to interface the RTL-SDR and a step by step guide to install the QSSTV software used to decode the signals.

Description of the beacon hardware and DDS frequency source used for G4JNT personal beacon

Alpha 87a Communication can be used either stand alone to control the Alpha 87a amplifier or together with several CAT-Control programs by HB9ZS

Build a SPDT coaxial relay that can be used as a main Transmit/Receive relay or an A-B switch to select between two different 6m antennas

NEC models are used to explore the GR5V and ZS8BKW optimizations. A third optimization is also rediscovered. The effect of fixed lengths of 75 ohm coax are explored. A link to the NEC model is provided.

Approximately 524,475 Brazilian amateur radio operators are cataloged within this resource, offering a comprehensive database for the South American region. Each entry includes geographical coordinates, enabling users to visualize station locations directly within Google Earth. This functionality supports DXers in identifying potential contacts and understanding propagation paths relative to specific Brazilian QTHs. The platform serves as a digital callbook, primarily focused on the Brazilian amateur radio community. It facilitates the lookup of callsigns and associated location data, which is crucial for award tracking, contest planning, and general operational awareness. The integration with mapping services provides a visual dimension to traditional callsign databases, enhancing the utility for operators interested in geographical aspects of radio communication.

The P4 Aruba Callbook, last updated in 2010, serves as a directory for amateur radio operators active from the Caribbean island of Aruba. It meticulously categorizes P4 callsigns into several types: **P41-** for special resident calls valid for one month, **P43-** for permanent resident calls renewable annually, **P49-** for permanent visitor calls also renewable annually, and **P40-** for temporary visitor calls valid for one month, often used in contests. The resource notes that obtaining a permanent visitor callsign requires passing a local examination. The callbook lists numerous specific callsigns, including their QSL routes, operator names, and sometimes addresses or activation dates. For instance, P41A routes via P43A, and P40HQ was used by P43ARC via I2MQP for IARU contests. The entries include both active and Silent Key (SK) operators, with dates of passing where known, such as P43ADA (SK, Sep 2014) and P43JB (SK Jan 2012). This detailed listing assists DXers and contesters in verifying contacts and ensuring proper QSLing for Aruba operations.

The prototype for this amplifier was originally designed for 70cm and was used on the 2004 3B9C Dx-pedition to Rodriguez Island for satellite and EME. It had a noise figure of 0.49dB with an associated gain of 20dB.

Sort of similar to the one of the 6m omni. Instead of using twin-lead, this design makes use of a more or less regular double bazooka antenna (coaxial dipole). Your attention shall be drawn to the available standart literature, such as Rothammel. In order to "compute" the dimension, Karl Rothammel mentioned that the total length of the dipole shall be 95% of the free-space wavelength. The short-circuit bridges (closing the folded dipole) are to be placed at a distance-fraction being equal to the velocity factor of the coax cable used, which will be 66% using RG-58 or RG174.

Focused on technology to serve emergency response in clackamas county, oregon.

Are you confused when it comes to using toroids? The tips given in this article may simplify your next project. Comprehensive article about choosing the proper toroid.

This paper discusses the sources of feed line currents and the methods used to control them.

This is a page to detail how I remotely operate my Elecraft K2 HF transceiver via my home network. The method used should apply to pretty much any amateur transceiver that can be controlled by serial port.

Operating Free DV, the open source digital voice codec for HF, allows any SSB radio to be used for low bit rate digital voice.

An overview about the UHF connectors often referred to as the PL259 plug and SO239 socket used for many RF applications. Limitations, history and soldering properly UHF Connectors

Designer and manufacturer of RF amplifiers used in a variety of custom applications in many diverse industries - from Scientific, Medical, Industrial, and Communications and Broadcast.

This is a standard calculation method that can help you while tuning dipole antennas, by adjusting wire lengths. This method can be used also when you need to add lenght to your wires, and can be additionally used to quarter waves vertical antennas

Removing noise caused by ignition and injection systems

Sound recordings of meteors and things reflecting TV station video carriers , frequencies used are analog TV video carrier frequencies offset by 1 kHz SSB

Grid Calculator allows you to calculate either a grid square locator or the latitude and longitude of a location. Grid Calculator can be used to calculate a Great Circle bearing and distance between two stations in statute miles, nautical miles, and kilometers.

A simple portable dipole antenna for the 40 meter band using a total lenght of 18 meter. It can be used for 80 to 10 meters coverage using a antenna tuner.

Ham shack located in a caravan and run by solar power. This page describes VK5SW experience of converting an old, disused and rundown caravan, to a fully functional solar powered Ham Radio shack.