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Tait Digital Mobile Radio (DMR) is an affordable digital communications platform that delivers a range of workforce efficiencies and operational benefits for mission critical users.

Alcatel Amateur Radio Association

The Crossroads of America Amateur Radio Ladies Association is an association of female amateur radio operators from Terre Haute, IN, and the surrounding area.

Although most Preselectors are designed with an internal T/R relay, theoretically enabling direct insertion between the transceiver and the antenna, there is a problem when running CW, especially when running full QSK. The switching time of the internal relay is too slow to follow full QSK. The best way to avoid this problem altogether is to insert the Preselector directly into the transceiver’s RX antenna line, thus avoiding entirely the need to switch the Preselector in and out.

Schematic diagram circuit to build a RS232 serial interface for the Yaesu FT 1000D, works also as CW Keyer control with Log-EQF software. May be used with other Yaesu HF Transceivers.

Asociaicon de Radioaficionados Minusvalidos Invidentes de Catalunya

A review of the dual band FT-8800R transceiver by the jeep expedition group

A dedicaed vertical antenna for 80 meters band based on a 40 meter vertical experiment

This article will cover gathering some software tools used for RFI location and removal.

Operating on Airplane scattering. Scattering of radio signals by airplanes. An introduction to operating ariplane scattering, using aircraft to redirect RF that would otherwise be lost in space. Antenna Pointing, Doppler Shift/Digital Modes, using digital modes to operate airscatter.

The Icom IC-PW1 is a 1000 watt linear amplifier with built-in power supply

A non profit 501(c)3 Public Charity Corporation supported by user donations

Aircraft Scatter Sharp is a windows application to calculate and assist airscatter operations. Real-time capture and display of plane position data derived from internet plane servers, highlighting of aircraft near the ideal position for scatter, Real-time estimation of Doppler shift and its rate of change.

The Icom IC-7300 is a popular SDR transceiver known for its excellent performance in ham bands. However, users have reported issues with reception reliability outside these bands due to ADC aliasing. This phenomenon occurs when the sampling rate of the radio interacts with frequencies outside the intended range, leading to unwanted signals being received. For instance, when tuned between 30 to 36 MHz, users may inadvertently pick up WFM broadcast signals or PMR communications due to aliasing effects. This guide outlines modifications to improve the IC-7300's performance by addressing the low-pass filter design, which is crucial for reducing interference from these unwanted signals. The proposed modifications involve adjusting the low-pass filter on the PA unit to better attenuate frequencies that cause aliasing. Measurements indicate that the original filter design allows significant signal leakage, leading to false receptions. By implementing the suggested changes, users can achieve a notable reduction in unwanted signals, enhancing the overall functionality of the IC-7300. While the modification requires careful soldering, the benefits in performance make it a worthwhile endeavor for serious operators looking to optimize their SDR experience.

The Salvation Army Team Emergency Radio Network (SATERN) is a vital resource for amateur radio operators involved in emergency communications. This network facilitates the coordination of communication during disasters, ensuring that vital information can be relayed effectively. SATERN operates through a series of nets that connect operators across various regions, allowing for real-time updates and support during emergencies. Participation in SATERN not only enhances your skills as an amateur radio operator but also contributes to community resilience. Operators are trained to handle emergency traffic and provide assistance to those in need. By joining SATERN, you become part of a dedicated team that prioritizes safety and communication in times of crisis. The network encourages regular participation in drills and training sessions to ensure readiness when real emergencies arise.

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.

GridLocW is a free Lat/Long to Maidenhead converter for Windows - with optional GPS support, includes the formula to calculate geodesic distance (in m) between two points specified by latitude/longitude.

The Utica Shelby Emergency Communication Association is a group of over 150 hams from all over the Metro-Detroit area

V63XG will be on the air from 4th December 2012

xCAT is an helper application for the FlexRadio 6000 series running on macOS computers to control via CAT protocol tranceivers, while xDAX purpose is to provide a way for Digital Mode Software like Fldigi, WSJT-X to access the digital audio data (DAX) of the FlexRadioTM

The Delta Amateur Radio Club (DARC) serves as a community organization for amateur radio operators in the Memphis, Tennessee area, providing resources and activities centered around two-way radio communication. The club maintains the W4BS repeater system, which operates on 147.060 MHz with a +600 kHz offset and a 100 Hz PL tone, facilitating local VHF communications. DARC actively supports the Amateur Radio Emergency Service (ARES), preparing members for public service and disaster response through training and coordinated drills. The club also hosts regular meetings and events, fostering camaraderie and technical skill development among its members. Membership in the Delta Amateur Radio Club offers opportunities for participation in various amateur radio activities, including field day operations and local nets. The W4BS repeater provides reliable coverage across the Memphis metropolitan area, serving as a critical asset for both daily ragchewing and emergency traffic handling. DARC's affiliation with the Amateur Radio Relay League (ARRL) ensures access to national resources and advocacy, reinforcing the club's commitment to promoting amateur radio and public service within the community. The club's focus on emergency communications strengthens local preparedness.

Map of locators of ecuador

Small company based in Santa Maria, California, designing and manufacturing electronic products for amateur radio, education, and commercial users. Product line includes APRS devices for real-time vehicle tracking, weather monitoring, and remote telemetry, as well as the ADS-SR1 Simplex Repeater, the ADS-WS1 Weather Station, the SSTVCAM slow-scan TV camera, and GTRANS protocol translator for Garmin FMI.

Map of locators of Uruguay

Picture and technical specifications of the Yaesu FT-8800R dual band transceiver

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.

DCI MotoTRBO IPSC Amateur Radio Group Our mission is to connect to and converse with the wider DMR Ham community by openly sharing our network resources and talkgroups to enable dynamic connections to all radio amateur DMR groups.

This article taken from the IARU Region 1 VHF handbook, is about the history of the original Locator System named QRA-Locator consisted of just five-character code, two capital letters, a two-digit number and a lower-case letter, like inf example CM72j

The Hurricane Watch Net (HWN) is an amateur radio organization dedicated to serving the National Hurricane Center and the public since 1965. It plays a crucial role in disseminating real-time tropical weather information for the Atlantic and Eastern Pacific regions. The HWN operates during hurricane events, providing updates and facilitating communication among amateur radio operators and emergency services. This network is essential for ensuring that communities are informed and prepared for severe weather conditions. In addition to its operational role, the HWN offers educational resources and outreach programs aimed at enhancing public awareness about hurricane preparedness. This includes providing access to tracking maps, storm surge information, and safety guidelines. The HWN encourages amateur radio operators to participate in its activities, fostering a spirit of community and collaboration in the face of natural disasters. By subscribing to their email updates, individuals can stay informed about active storms and receive vital safety information.

I have RFI, now what– Locating it. This article is the first of a three parts article, that covers the problem of locating the RFI source. Author make use of an SDR receiver to locate RFI emissions. Ai interesting RFI location process diagrams helps on following the various phases, permitting the discovery of almost 75% of the RFI issues.

Map of locators of Bolivia

Results or performance test using an harpin antenna for the 7 MHz

Aircraft scatter is easily seen on the spectrogram window of digital communication apps, when you know what to look for. Examples of real aircraft scatter usage on six meters band

Modifying the Collins KWM-2 for Serious CW Operation, Make this old SSB workhorse perform like it should on CW.

Procedure for foreign ham radio licensees to establish a station in Japan

Alpha 87A Amplifier Fault 1 and the downlevel amplifier

Online HF Communication prediction system provided by the Australian Governament Buerau of Metereology allow to predict usable frequency rage for radiocommunications between two stations allowing to specify frequency and date range. This tool allow calculation with different methods and algorithms

This page provides a list of scanner frequencies for hams in the UK. It offers a comprehensive guide for ham radio operators looking to find and tune into various frequencies for communication. The page is useful for hams who want to explore different channels and connect with fellow operators in the UK. Whether you are a beginner or an experienced ham radio enthusiast, this resource can help you discover new frequencies and expand your communication network.

These frequencies have been adopted into the bandplans of each IARU region to be a focus for emergency communications in their areas. They are not absolute frequencies but instead are centres of activity and emergency communications may be found around 20kHz from these centres. Some countries may maintain other emergency frequencies in their own bandplans due to local requirements, QRM etc

The Utica Shelby Emergency Communication Association is a group of over 150 hams from all over the Metro-Detroit area. This club is the largest and most active club in southeast Michigan.

Reflected power and VSWR Metering on Yaesu FT-817, and proper interpretation of real values. The power output meter it is a relative indicator of the antenna match that the radio is experiencing. Reference table and how correctly read the values of the Yaesu internal meter.

The U01 emergency communications antenna is a versatile, multiband antenna designed for 80/60/40/20/17/15/10m bands, known for its reliability and compact size. It features a broadband transformer wound on various core options like FT82-43, FT114-43, or FT140-43, with the latter capable of handling up to 100W. The antenna incorporates a PCB with options for SMA and BNC connectors, and a weather-proofed design for durability. The lightweight construction, using materials like DX Wire UL and Polyester rope, makes it highly portable. The antenna's design has been tested and proven within the DARC Chapter U01, with multiple build options and detailed documentation available for DIY enthusiasts.

QSO Procedure for Airplane Reflections, Reporting system and procedure, confirmation procedure and requirements for a complete QSO

Aircraft can also be used to increase communications range, by using Aircraft Scatter

You can use this tool to calculate the maidenhead square by entering the longitude and latitude.

IOTA DXpedition will happen from 9th till 18th of April 2018 OC-265

Showing aircraft scatter reception in action.

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.

This page provides a fully customizable band plan. You can easily customize the frequency limits, scale, define custom windows for modes and activities, adding or removing bands. You can tehn Export to PDF or print the bandplan to distribute the document to help hams operating within the designated spectrum efficiently. Useful for both new and experienced hams looking to produce their custom bandplan.