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Operating under the callsigns G1ORC, G4ORC, and M5ORC, the Oldham Amateur Radio Club (OARC) serves as a local hub for radio enthusiasts in Royton, Oldham, England. This RSGB-affiliated organization welcomes individuals with an interest in any facet of radio communication, fostering a community environment for learning and on-air activity. The club maintains an active calendar, detailing upcoming amateur radio events and specific courses hosted by OARC, providing a structured approach to engagement for its members. Club activities are centered at the No.1855 (Royton) Squadron Air Training Corps on Park Lane, a consistent meeting point for members. This physical location facilitates hands-on learning, equipment demonstrations, and social interaction among hams. OARC's commitment to the hobby is evident through its multiple transmitting licenses, enabling diverse operational experiences for its members across various bands and modes.

The Tararua Amateur Radio Club, Branch 06 of the New Zealand Association of Radio Transmitters (NZART) is an incorporated society for Radio Amateurs and interested persons.

Hong Kong Amateur Radio Transmitting Society

A magnetic loop antenna designed for 14 MHz. This kind of antennas is also known as STL, small transmitting loop and can be an excellent solution when you are not allowed to put antennas on your roof

The Coulsdon Amateur Transmitting Society (CATS) website provides information on meeting schedules and an informational flyer. The content is concise and objective, catering to radio amateurs and technical users.

PSK Reporter provides a real-time visualization of amateur radio digital mode reception reports, aggregating data from a global network of monitoring stations. This platform is particularly useful for operators utilizing modes such as FT8, FT4, and PSK, allowing them to observe signal propagation paths and assess their station's reach. The interactive maps display reception reports, enabling hams to analyze band conditions and optimize antenna performance for various frequencies and times of day, aiding in understanding ionospheric conditions. Operators can filter reports by callsign, band, mode, and time, gaining insights into specific propagation events or evaluating the effectiveness of their transmit setup. The data collected helps in predicting optimal operating windows for DX contacts across various digital modes. Philip Gladstone is the contact person for comments and discussions regarding the system.

QSK 2500 enhances HF amplifiers by enabling full break-in (_QSK_) operation, allowing for seamless communication during CW transmissions. This device supports **all** HF transceivers that are QSK-compatible, ensuring versatility across various setups. The QSK 2500 facilitates quick switching between transmit and receive modes, which is crucial for effective DXing and contesting. With its straightforward installation, operators can achieve **improved** responsiveness in their communications without the need for extensive modifications to their existing amplifiers. This project is particularly beneficial for those engaged in high-speed CW operations, where timing is critical.

On the field comparison among C-Pole antenna, an EFHW vertical antenna and an Inverter V dipole antenna. Test is done using two identical WSPRLite beacons that transmit with 200mW on the WSPR frequency and analyzing spotted results.

Active RDF club in California

Illustrates the fundamental principles of radio repeaters, detailing their role in extending communication range beyond line-of-sight limitations. It begins by defining _simplex communication_ as a direct radio-to-radio link, effective only when no obstructions impede the signal path. The resource then introduces the concept of a repeater (or base station) strategically positioned on elevated terrain, such as a mountain, to overcome geographical barriers. The article clarifies the repeater's operational mechanism: it receives a signal on one frequency and simultaneously re-transmits it on a different frequency, enabling users on opposite sides of an obstruction to communicate. This _duplex operation_ is likened to satellite communication for VHF propagation, but with a fixed terrestrial station. Specific examples of signal paths are provided, showing how a handheld radio transmits up to the repeater, which then relays the message down to another user, effectively bypassing obstacles like hills or large buildings.

Identity of wwff/svff while having a qso with a svff expedition you are welcome to transmit also and two figures

The Meteor-M N2 is a polar orbiting Russian weather satellite that was launched on July 8, 2014. Its main missions are weather forecasting, climate change monitoring, sea water monitoring/forecasting and space weather analysis/prediction. Meteor-M N2 transmits images using the digital LRPT protocol at around 137.1 MHz with can be received with an RTL-SDR.

Operating as FY/F5UII, Christian F5UII conducted a DXpedition to French Guiana (FY) from January 13 to 30, 2013. The primary operation utilized the FY5KE radio club station in Kourou, with activity focused on voice modes during specific weekday hours. The resource details the operator's intent to transmit before 12:00z and after 22:00z, or as availability permitted, from the mainland. A significant aspect of this operation involved a dedicated weekend activation of the Salut Islands, specifically **IOTA SA-020**, from January 19-20, 2013. This segment of the DXpedition was conducted from Royal Island (Ile Royale), part of a group including Devil's Island (Ile du Diable) and St. Joseph Island (Ile Saint Joseph), located 14 km offshore from Kourou. The station setup for the IOTA activation included 100 Watts of power, a GPA-030 vertical antenna for 10m, 15m, and 20m, and dipole antennas for 17m and 40m, with antenna deployment contingent on site conditions and propagation. The operator anticipated strong interest for the SA-020 entity.

This transmitter covers the 160, 80, 40 and 20 metre bands and provides both SSB and properly generated CW. The CW side of this transmitter is not compromised and produces excellent CW. On SSB the audio has been tailored to provide a rising response to 3 KHz, with a sharp drop above that frequency. There is RF speech clipping to both provide more "punch" and to limit the peak output.

DXSPOTS is a Telnet connection program. It allows radio amateurs with a lot of DX traffic to know instantly the status of the bands and to know which DX are currently on the air. Following the Packet-Clusters where data was transmitted on VHF/UHF via dedicated relays and sometimes on HF at a very low speed (300Bds on HF), the Internet has taken over and is now transmitting DX information via the computers in most shacks. Translated with www.DeepL.com/Translator (free version)

This is a small collection of K9YC info and my experiences. Problems by feed lines of 1/2 lambda length. CMCs in transmitting and receiving systems. Antenna unbalance, Maximal allowed power, Choke winding tips.

Explore two magnetic loop antenna constructions, utilizing a 6-foot and a 12-foot square loop. Accompanied by a detailed description, the 6-foot loop features a built-in stepper motor control circuit, while the 12-foot loop incorporates a separate loop controller. Efficiency, tuning ranges, and the innovative autotuning solution using a microcontroller are discussed, offering insights into overcoming the antenna's narrowband limitations.

This blog article introduces an updated repeater controller project utilizing the Arduino UNO. It includes a CW identifier, and the ID message can be customized using hex codes. The author offers a Windows command line program for easier message coding and provides a link for download. The controller features three adjustable timers for IDer, Timer-out, and Squelch-tail. The article also mentions the use of an audio switch to control audio levels between the receiver and transmitter. Detailed instructions and code files are available on the author's website for both version 1 and version 2 of the Arduino repeater controller. The project aims to enhance repeater functionality and audio management in ham radio operations.

Basic information on code plugs. What code plugs is, how to set up a code plug, transmit talk groups and configuring zones.

Explains the fundamental purpose of a repeater, detailing how these automated relay stations overcome distance and terrain limitations for VHF/UHF communications. It traces the historical development from early Bell Telephone Labs "relay" stations in 1922 to Art Gentry, W6MEP's, pioneering K6MYK amateur radio repeater in the mid-1950s, which remains active today. The resource clarifies the distinction between simplex and duplex operation, including the unique function of a "parrot repeater" for single-frequency recording and playback. Delving into the internal workings, the guide breaks down a repeater into its core components: the antenna system, feedline (often _Heliax_ or hardline for minimal loss), duplexer, receiver, transmitter, and controller. It emphasizes the critical role of the duplexer in preventing receiver desensitization by isolating transmit and receive signals, even with distinct frequencies. The discussion highlights the importance of high-performance, durable antennas and low-loss feedlines, citing examples of equipment installed in the 1960s and 1970s that are still in perfect working order. Operating a repeater is also covered, with an explanation of frequency offset (e.g., the 600 kHz standard for 2 meters) and the function of _CTCSS_ (PL tone) for access. It outlines standard input/output offsets for various bands, from 6 meters to 23 centimeters, while noting regional variations. The guide also touches on features like autopatch and Digital Voice Recorders (DVRs), providing a solid foundation for understanding repeater technology and usage.

This article introduces an Arduino-based QRP CW Transceiver designed for lower HF bands. The journey begins with the Wotduino, evolving from a keyer to a multi-mode beacon. The development includes a QRP transmitter and culminates in a receiver inspired by Roy Lewallen design. The transceiver, controlled through a control bus features a signal path, modulation, filtering, and adjustable frequency settings. Despite initial testing intentions, successful QSOs on 80 and 40 meters showcase its functional capabilities.

The video showcases the setup of a 300 MHz oscillator, a 100W radiofrequency amplifier, and a dipole antenna for transmitting radio waves, leading to the fluorescence of a nearby light bulb. It demonstrates the presence of standing waves on the dipole antenna and how intensity varies along its length. Additionally, the usage of a copper pipe as a receiving antenna is explored, showing changes in intensity depending on alignment and proximity to the transmitter. Finally, a B field antenna sensitive to magnetic fields is introduced, revealing brightness variations in different orientations. The video offers insightful observations on radio wave transmission and reception phenomena.

Home made 40 meter transceiver project. The receiver is a Progressive Receiver with a few modifications. The Transmitter is a modified MFJ Cub circuit. Includes schematic and circuit diagrams for Receive Input Filter, 3-Pole 500 Hz Cohn Filter and 7 MHz Double Tuned Bandpass Filter

Review of Yaesu VX-3R 2 m/70 cm FM transceiver. Receives 0.5-999Mhz AM/FMN/FMW, Transmits 144-148 and 430-450Mhz VHF/UHF FM.

The _G3TSO_ Mobile Antenna Page details construction and tuning methods for mobile antennas operating across **10 to 160 metres**. The content describes a Hustler-based design, optimized for RF performance and vehicle speeds, featuring centre loading. For optimal operation on various bands, the loading coil placement requires clearance from the vehicle body. Antenna resonance is critical for efficient mobile operation. A mobile antenna's base impedance may be as low as 27 ohms, requiring specific matching to achieve maximum radiation, as a minimum SWR at the transmitter does not always indicate resonance or maximum output. Tuning involves physical adjustment of antenna length to achieve resonance at the operating frequency. The _G3TSO_ page outlines a tuning procedure utilizing a low-power signal source and a field strength meter to identify maximum radiation before impedance matching. Loading coil placement, either at the base, center, or top of the antenna, influences radiation efficiency and mechanical stability for mobile installations. Centre-loaded whips, such as the Hustler design, offer a compromise between efficiency and stability, often for single-band operation. Helically wound antennas, including those for **28 MHz**, may present base impedances around 17 ohms, resulting in a 3:1 SWR at resonance. Low resistance grounding at the antenna base is also specified for optimizing performance and minimizing RFI during mobile operation. DXZone Focus: Mobile | Any | Antenna Tuning | HF

In the field of RTTY transmissions with audio boards, you can transmit either in FSK or AFSK mode. Which is better: FSK or AFSK? Advantages and Disadvantages of both methods

The 1 watt 20 meter QRP transmitter with VXO. This is a nice QRP transmitter that can be used in combination of one of the simple receivers.

The weather station described here uses a TTGO v3 1.6.2 module and various sensors. It displays the data on an OLED screen and transmits them among a choice of protocols to the APRS, APRS-IS, Wunderground servers or via an MQTT broker. APRS data is transmitted on 433.775 MHz (can be changed) using the LoRa protocol. APRS beacons picked up by iGate gateways are then transmitted to APRS servers.

About LoRa, wireless communication technology designed to transmit data over long distances. LoRa provides a means for wireless data transmission over long distances with low power consumption. Practical applications of LoRa in amateur radio

Learn about the practical design and construction of Yagi antennas for ham radio operators. This post explores the benefits of Yagi antennas in receiving and transmitting RF signals, concentrating signal energy in one direction for long-distance communication. Discover the theory behind Yagi antennae, the importance of element size and spacing, and the resources available for sizing and construction. Whether you're interested in OTA television or amateur radio communication, understanding Yagi antenna design can enhance your signal reception and transmission capabilities.

This document details the construction, programming, and operation of a modular WSPR transmitter. The transmitter utilizes an ESP8266 NodeMCU, an SI5351 synthesizer with a TCXO for stability, and selectable low pass filters. Construction involves soldering headers, components, and assembling filter module. The ESP8266 is programmed via the Arduino IDE, requiring library installations and code modifications, including network credentials, callsign, and frequency . The transmitter is powered by USB or Vin terminals and its frequency is selected by jumpers and software settings. The document also covers FCC restrictions and how to use the WSPR network

Vertical antenna tests at the Sonten-Rancabali tea resort in Ciwidey, West Java. The assembly, led by Mr. Dian Kurniawan and the team, took just 20 minutes. Mrs. Mita performed the transmit check-in test, which was received across various regions in Indonesia, including Sulawesi, East Java, and Bangka Belitung. The team will release a video of the test soon and has thanked colleagues YB3HRY and YB0BAW for their reports.

Presents two distinct hardware modifications for the Icom IC-7300 transceiver, detailing the necessary steps for each. The first modification, a _MARS_ transmit expansion, involves the physical removal of specific surface-mount diodes (D422) from the main board, enabling transmit capabilities across a broader frequency range, including out-of-band frequencies. It specifies the diode location on US versions of the IC-7300 and suggests using small diagonal cutters if a soldering iron is not preferred or available. The second modification focuses on the internal antenna tuner, aiming to provide wider impedance matching capabilities. This involves adding a **100k ohm** resistor to a designated point within the tuner circuit. The resource also briefly mentions a microphone modification for the _HM219_ and a general power increase, though without specific instructions for the latter two. It emphasizes safety precautions, such as disconnecting power and inspecting the work area.

1-watt 17-meter cw transmitter that was originally done about 10 years ago as a club project for RAMS, the Radio Amateur Megacycle Society. It uses a VXO, rather novel at the time. It also uses a bandpass filter at the output rather than the usual lowpass

On this page, you will find one of my designs; An Audio Selection Panel (ASP). The Audio Selection Panel allows you to control 4 Transceivers and hear the audio through the built-in loudspeaker and on an external boomset (combination Microphone/ headset). On or more transceivers can be selected at a time to transmit and/ or receiv

Cavity is often required at a busy site to not only prevent its receiver from being overloaded by off-frequency signals, but also be a good neighbour and prevent low-level signals from your transmitter from getting into other users receivers - not to mention the preventing of those other signal from getting back into your transmitter to generate spurious signals in its own right.

Visualizes real-time amateur radio propagation spots using data from the PSK Reporter MQTT stream, providing immediate situational awareness for radio operators. The platform displays spots from various modes, including CW, WSPR, and JT65, in addition to the dominant FT8 digital protocol. FT8 Live focuses exclusively on live data streams, prioritizing current signal activity over historical archiving, which differentiates it from the official PSK Reporter map. A key feature is its integration with the Summits on the Air (SOTA) API, facilitating SOTA chasing by cross-referencing transmitting callsigns with SOTA alerts; a station is identified as an activator if the spot correlates with a scheduled alert within an eight-hour window. The user interface was developed by Arron (ZL1AN), with core data from Philip Gladstone (N1DQ), and stream delivery managed by Tom Stanton (M0LTE).

Ribbit is a novel digital text messaging mode for VHF/UHF communications for recreational and emergency use which radically increases the density of information transmitted by spectrum used. It leverages the computing power of the modern smartphone to increase the capabilities of any Handy Talkie without requiring any additional hardware or cable. A Ribbit message is fixed in duration at 1250 milliseconds. It is sent over audio modulation with a 2kHz bandwidth centered on 1.5kHz. It is preceded by 400ms of white noise to open analog squelch circuits.

Due to the nature of PSK it is imperative that you maintain a very clean signal. In this page you will find examples of a clean PSK signal and one with excessive splatter, and a short guide on how to properly adjust your transmitter to assure a clean trace

Worldwide Map of shortwave transmitters. Based on shortwave schedule database, this website let you serarch using filters for broadcasts schedule and at the same time to diplay the transmitter map.

Explaining ARRL Technical Reviews of Radios a brief tutorial on radio testing. The ARRL Lab tests radio equipment according to standardized test procedures, using calibrated professional test equipment. Info on transmitter and receiver tests

A 70cm / 432 MHz Transverter Project transverter circuit is an electronic device that converts a radio signal from the 2 meter to the 70 centimeter band and vice versa, allowing a single transmitter/receiver to be used for both bands. It consists of an IF stage, local oscillator, frequency multiplier, and amplifier. The circuit must be designed for minimal signal loss, noise and intermodulation distortion.

A simple 2-tone-generator for testing the linearity of SSB transmitters. This device is as simple as useful. With 2 transistors and an oscilloscope, it is fairly easy to test the linearity of your SSB transmitter. The 2-tone-method is a standardized test method that can be used to determine the maximum output and the amplification characteristics of a sideband transmitter.

A transmitting antenna 2x15m, about 100 foot doublet antenna fed by a ladder line of about 600 Ohm. Article in Polish and English,

Reviving the spirit of early ham radio experimentation, the CW Flea is a contemporary Morse code transmitter. Utilizing an Arduino Nano, Si5351 clock generator, and innovative design, this open-source project offers simplicity, flexibility, and easy tuning for aspiring radio enthusiasts.

The 222 MHz Transverter project, based on Zack Lau's (W1VT) original July 1993 QEX magazine design, provides an IF of 28 MHz for both transmit and receive paths. Rick Bandla (VE3CVG) contributed supplemental notes and construction details, including modifications to achieve 10 mW output power from an initial 4 mW PEP. The design incorporates three distinct boards: a Local Oscillator (LO), a Transmitter (Tx), and a Receiver (Rx), with an estimated parts cost of just over $150 CDN, significantly less than commercial kits. Construction involves both through-hole and surface-mount components, with specific guidance on mounting MAV and MAR devices, grounding techniques, and component selection. The project details include parts lists, schematics for the LO, Tx, and Rx, and board layouts. Troubleshooting advice emphasizes sequential testing, starting with the LO, then Tx, and finally Rx, using a 194 MHz and 222.100 MHz capable FM handheld for signal tracing. Further enhancements are discussed, such as an optional Tx driver stage to boost output to 100 mW and the potential modification of a Motorola Maxor 80 PA for 222 MHz SSB/CW operation. The resource also covers practical aspects like power attenuation pads for IF radios (e.g., FT817) and considerations for enclosure design, including repurposing a Maxor 80 case. Performance reports indicate successful 70 km contacts with only 4 mW output.

This page offers an online antenna designer to calculate the dimensions for a collinear dipole antenna at a specified frequency. The collinear dipole antenna is constructed with multiple 1/2 wavelength sections separated by a 1/4 wave phasing stub in the form of a coil. It requires a ground-plane to operate and can be used for both receiving and transmitting purposes. The antenna can be made from common copper wire, with thicker wire providing a wider bandwidth. The calculations are based on radio waves traveling at the speed of light. Ideal for ham radio operators looking to build their own antenna for improved reception and transmission.

The document details the construction and performance of a rotatable flag antenna designed for a small lot. The 7x14 feet flag, built with fiberglass poles and an aluminum hub, shows improved reception compared to the author's previous transmit antenna. Key components include a conventional transformer for impedance matching and a variable resistance termination system to optimize performance. Despite challenges like nearby objects affecting signal patterns, the antenna consistently provides better signal-to-noise ratios, making it a valuable addition for low-band listening in suburban areas.

The Score Distributor facilitates real-time score forwarding for amateur radio contests, automatically transmitting data from various logging software to multiple online scoreboards. By configuring logging applications to send score data to the Distributor, operators ensure their current score is simultaneously represented on platforms like the _Contest Online ScoreBoard_ (COSB) and the Live Contest Score Server by R4WW. This system eliminates the need to choose a single scoreboard, providing broader visibility for participants. This utility enhances the competitive experience by allowing contesters to monitor their performance against other stations throughout an event. Observing real-time standings can provide significant motivation, particularly during periods of challenging propagation or when striving to maintain pace with club members or peers. The platform supports almost all major contest logging software, simplifying integration for a wide range of operators. Developed by WA7BNM, the Score Distributor was last revised on June 14, 2023. It aggregates score data, offering a unified point of submission that then disseminates the information, ensuring a **single point of entry** for broad scoreboard coverage and improving the dynamic feedback loop for participants.

Exploring digital radio modes, the author rethinks how to adjust transmit and receive levels in WSJT-X. Despite effective communication using Yaesu's settings, a new procedure aims for better performance. For RX, set audio device levels to 100%, disable AGC, and adjust RF gain. For TX, enable "Remember power settings" and adjust power output to avoid ALC engagement. This method ensures reliable communication without signal degradation, enhancing dynamic range and minimizing noise.