Search results

The Martello Tower Group is an amateur radio group which was originally formed in the late 1980s under the name ClackPak.

Pigeon Island,Reef Islands,Temotu Province,Solomon Islands 7-22 October 2010

Review of the excellent ICOM IC-R8600 Wide Band SDR communications receiver. Featuring Direct Sampling SDR below 30 MHz Hybrid Superhet / SDR above 30 MHz.

KA4RRU/B Ten Meter Beacon

An original amateur radio blog in Esperanto lenguage, all about ham radio, DX, antenna.

Remote viewing can be useful for Hams, in example remotely viewing antennas during a storm.

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

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.

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

The Icom IC-7700 spectrum scope feature a minimum resolution bandwidth of just 100 Hz and provide also an accurate vertical amplitude tracking permitting to use the 7700 as a bench spectrum analyser.

Official web site of the VP6D DXPedition to Ducie Island 20th October - 3rd November 2018 IOTA OC-182

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.

Large collection of 1900's antique Radios for sale,Floor model, Cathedral, table top, Novelty, Battery, police and broadcast band image gallery

A multi section article on learning the morse code for beginners. The article include a list of tips the author consider to be uesful when someone want to begin the trip to learn the morse code.

A Magnetic Loop Controller project details the construction and operation of an automatic tuning system for magnetic loop antennas, which are resonant circuits using an oversized inductor and an adjustable capacitor. The system employs a stepper motor to precisely adjust the variable capacitor, maintaining optimal resonance across the HF bands. It integrates with various transceivers, including _Icom_, _Kenwood_, and _Yaesu_ models, by monitoring the VFO frequency and adjusting the loop's tuning accordingly. The project provides comprehensive building instructions, a PowerPoint-style presentation, and the full source code for the controller's firmware, enabling hams to replicate and customize the design. The controller's firmware offers diverse functionality, including automatic frequency tracking, manual tuning, and SWR monitoring, significantly enhancing the operational efficiency of magnetic loop antennas, particularly for QRP and portable operations. The design emphasizes accurate capacitor positioning, crucial for achieving low SWR and maximum radiated power. Comparisons with manual tuning methods highlight the benefits of real-time adjustment, especially when operating across different bands or making frequent QSYs. The project's detailed documentation and available source code facilitate experimentation and modification by advanced builders, allowing for tailored performance characteristics.

About Continuous Tone Coded Squelch System. In the amateur radio community CTCSS encode is referred to as Tone in radio programming and CTCSS decode is referred to as tone squelch

July 2017 DXpedition to Miquelon SSB, CW, RTTY - 80M - 10M

FreePCB is a free, open-source PCB editor for Microsoft Windows, released under the GNU General Public License. It was designed to be easy to learn and easy to use, yet capable of professional-quality work.

Schemaric diagram for a 80m, 40m, 30m, 20m EFHW Antenna Antenna Tuner. The tuner has been designed for an antenna length of 41m and the counterpoise 7.5m.

Make your own dipole for 40 and 80 meters band, assembling standard product parts like 40 meter traps, the 1:1 balun and insulators

Notes on installing the miniVNA PRO software, making a calibration standard, a trap tuning loop.

A simple and cheap solution to monitor temperature of your repeater implementing a Raspberry Pi device with a set of popular tools made in python a database and RRD tool

The UniBalun is a PCB for building a lightweight antenna transformer (Balun) or impedance converter (UnUn) for low power radios. By soldering jumpers and a toroid core, you can create a 1:1, 1:4 Balun or 1:49, 1:9 UnUn. The latest revision (1.2) includes improved pads and supports both BNC and SMA connectors. Build instructions are available for German speakers.

This page details the restoration of an early production Collins 75A-4 Amateur Band Receiver that had previously been vandalized.

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.

Common issue on the TYT MD-390 when the speaker start sounding like it is broken, but it depends by the external mic cover.

The document discusses the classifications of sunspots and their potential for solar flare activity, categorizing them into Alpha, Beta, and Delta groups based on their magnetic field characteristics. It explains how these classifications relate to the likelihood of solar flares, ranging from minor to extreme events. The report also outlines the geomagnetic indices and conditions that affect high-frequency (HF) radio propagation, emphasizing the effects of solar flares on radio communication and geomagnetic storms. The information is geared towards amateur radio operators, providing insights into how solar activity influences HF radio operations.

The Washington County Amateur Radio Club (WCARC) was formally established on June 26, 2014, serving amateur radio operators and enthusiasts in Washington County, Texas. The club provides a local community for hams to gather, share knowledge, and participate in various radio activities. Its formation date indicates a relatively recent establishment within the amateur radio landscape. The WCARC aims to foster interest in amateur radio, offering a welcoming environment for both licensed operators and individuals new to the hobby. Membership is open to anyone with an interest in amateur radio, promoting engagement across different experience levels. The club's activities likely include regular meetings, field operations, and support for emergency communications within the local area.

Antique and Vintage Speaker Restorations for over 35 years. Grunow,Atwater Kent,Fairbanks Morse,McMurdo, Stewart Warner,to name a few.

A project for a 5-over-5 stack on 10 meters

In this article we share a useful and simple project to convert an unneeded car power cable to an Anderson PowerPole adapter.

This project taps into the NMEA stream and provides both a visual display with an LCD and also LED indicators and a sounder. The LCD outputs include 3D Lock, 2D Lock and NO Lock while the UTC time is also displayed to screen.

For this project, I decided to try my hand at building a Z-Match tuner from scratch. This type of tuner has been around for a while. While the Z-match can take on several variations, what distinguishes it from other circuits is that it is a resonant circuit that uses a fixed inductor.

Originally designed by John Kraus, W8JK in about 1940, this antenna has some interesting properties. The W8JK antenna is 2 (Two) centre-fed double-dipole fed by a pair of anti-phase signals. Small size, simple antenna, offer nice performance but need a tuner. Tested in this project from 30m to 6m bands

Personal page of the Dutch Amateur Radio Station PA1CW

Operating within the low-frequency spectrum, transformers serve critical roles in antenna systems, particularly for 160m applications. The resource details the construction and performance of 1:1 transformers built on BN-73-202 cores, emphasizing their use as hybrid combiners or phase inverters for RX antenna arrays. Measurements reveal that these transformers exhibit minimal losses, around 0.12 dB at 1.8 MHz, with variations based on wire type and number of turns. The analysis includes comparative data on transformer performance, highlighting the impact of different winding techniques on frequency response. Notably, the use of coaxial cable for winding improves bandwidth while maintaining low-frequency efficiency. The resource also discusses braid breaker transformers, which minimize inter-winding capacitance, achieving low losses around 0.21 dB at 1.8 MHz. These insights are crucial for optimizing low-band antenna systems, allowing operators to make informed decisions regarding transformer design and implementation.

Vanuatu YJ0X, DX pedition 3-14 October 2014

A coaxial cable trap is a fundamental component in multiband antenna design, enabling a single radiator to resonate efficiently on multiple frequencies by electrically shortening or lengthening the antenna element. This project focuses on constructing such a trap for a vertical antenna operating on the 10 MHz (30m) and 14 MHz (20m) amateur bands, providing practical insights into its fabrication and integration. The article outlines the specific dimensions and winding techniques for the coaxial trap, emphasizing the use of readily available materials. It details the physical construction of the vertical element, including the mast and radiating sections, to achieve optimal performance across both target bands. The author shares personal experiences with similar trap designs, noting their effectiveness in previous horizontal dipole configurations. Key construction steps are illustrated with _original photos_, showing the assembly of the trap and its incorporation into the overall antenna structure. The design aims for a compact footprint, making it suitable for limited space installations while still delivering effective DX capabilities on the **30-meter** and **20-meter** bands.

RDF Equipment Ideas for VHF Foxhunting and Radio-Orienteering. This information is primarily for the Amateur Radio two-meter band

H44MS is call of DL2GAC during DX vacations in Solomon Islands 1.Febr. to 30.April 2015

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.

An article on amplitude modulation (AM) operation on VHF bands.

Raspberry Pi Telemetry Station project by Burns Fisher, WB1FJ , Chris Thompson G0KLA/AC2CZ. A step by step guide on Building a Fox-In-A-Box The Easy Way, A Prebuilt SD Card Image or from scratch.

This is a Bourne Shell script that will automagically download the FCC Amateur Radio license database, parse it, and populate a MySQL database. The database can be searched using the command line and is very fast.

Web site and blog that reviews equipment, goes over safety, and display projects being built. Includes Yaesu FT-891 and Ameritron RCS-10 Review, a 555 Morse Code Practice Oscillator, and and arduino based Morse Code Practice Oscillator

Since 1992, MATsolutions has delivered the assurance our clients need when acquiring, maintaining, and managing high-quality test and measurement equipment. Used Electronic Test & Measurement Equipment Sales, Calibration, Repair & Services

Construct the Peaberry, a SoftRock-compatible SDR transceiver. This project is aimed to build an amateur radio transceiver that operates on the medium or short wave bands

There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the VNA measurements, and in the process discovered how to build better transformers and be able to predict what they will do

Probemaster manufacturers probes of all kinds, including oscilloscope probes, differential probes, test leads and much more, all proudly made in the USA

Creating a 2m Fm Repeater with a Raspberry Pi (B) and a RTL dongle.