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A 4 element yagi beam antenna for the 17 meters band with pictures and element dimension and spacing

Amateur radio spectrum management and frequency coordination entity for 219

The VK3UM EME Planner is just a planner and supports several functions useful for EME operations

Using portable generators during emergencies or at field day site, using batteries and how to recharge them, using solar panels.

An information paper by the International Amateur Radio Union, History of 40m allocation, propagation properties of 7 Mhz band

Simulation of the Konni Antennen 5 Element for 50 MHz

This resource provides fundamental guidelines for optimizing mobile amateur radio antenna installations. It addresses critical factors such as achieving an adequate ground plane, minimizing common mode current, and reducing ignition noise. Specific recommendations include mounting antennas on the vehicle's roof for superior radiation patterns and utilizing proper feedline routing to mitigate RF interference within the vehicle's electrical system. The content details the impact of antenna placement on Standing Wave Ratio (SWR) and overall radiated power, emphasizing the importance of a solid electrical connection to the vehicle chassis. It also discusses strategies for noise suppression, such as bonding body panels and employing ferrite chokes on power leads. The information presented is practical for hams seeking to improve their mobile station's efficiency and reduce RF-related operational issues.

ON7YD narrowbands modes on 136 Khz

A 2 elements delta loop antenna for 14 MHz with a MMana simulation file, dimensions, pictures of this aluminium tube based delta loop antenna, and matching system details.

This calculator is designed to give the critical information of a particular beam antenna, in this case a three element Yagi, for the frequency chosen.

A 2 element beam antenna for 80 meter band by ha8rm

For over 15 years, the putnamemergency and amateur repeater league (pearl) has been providingthe citizens of putnam county, n.y. with emergency and public services.

Yaesu FT-817 noise blanker improvement

The Indianapolis Police Scanner on Broadcastify allows users to listen to live police radio transmissions from Indianapolis. The website provides access to emergency communications and public safety broadcasts.

Presents a dedicated logging solution for amateur radio DXpeditions, addressing the unique operational demands of remote or temporary stations. This freeware Windows application provides essential tools for managing QSO data, ensuring accurate record-keeping during high-volume operations. The software supports efficient entry and retrieval of contact information, crucial for verifying DXCC credit and submitting contest logs. It streamlines the process of logging contacts, which is vital when operating from rare entities or during intense pile-ups, helping operators maintain focus on making contacts rather than complex data management. The application aims to simplify the logistical challenges associated with DXpedition logging.

A modification to improve quality of built-in FT-817 Noise Blanker

The page provides circuit improvements for the Kenwood TS-440S transceiver, addressing issues such as distortion in SSB signals, limited transmit frequency coverage, lack of crispness in RX audio, and flat audio response. The fixes include adjusting bias, cutting specific components, and changing capacitors to improve performance.

A Six element antenna for the 50 MHz Amateur Radio Band v4 by DF9CY

Guidelines for optimal speaker placement inside our ham radio shacks

RF Current measurements on a Long Wire W3EDP antenna

Operating the AO-51 amateur radio satellite with a handheld transceiver (HT) presents a practical entry point for newcomers to satellite communications. This resource details the necessary steps and considerations for making basic contacts, focusing on accessible equipment. It covers fundamental concepts such as _Keplerian elements_ for satellite tracking and the importance of understanding Doppler shift effects on both uplink and downlink frequencies. The tutorial outlines a straightforward approach to satellite passes, emphasizing the use of readily available gear. It provides insights into antenna orientation and timing for successful two-way communication. The content aims to demystify satellite operation, enabling operators to achieve their first **AO-51** contacts with minimal specialized equipment. Key aspects include frequency management and basic operational techniques.

Le Club radio-amateur Beziers

The C.A.R.E.N. Club is one of the oldest amateur radio clubs in Arkansas, dating back to the late 1950s. Just as the name implies, the C.A.R.E.N. Club is the state leader in emergency communications, SKYWARN, Amateur Radio Emergency Service (ARES), Radio Amateur Civil Emergency Service (RACES).

2-Element-12,5-Ohm-Yagi with 0,40m-Boom complete description of all details for building this Yagi and stacking to an array

The CES Wireless Technologies website details a range of **GPS fleet tracking** solutions designed for mobile information systems. It highlights offerings such as dispatch and mapping software, Automatic Vehicle Location (AVL) systems, and mobile data display terminals. The platform also mentions support for Automatic Number Identification (ANI) and Continuous Tone-Coded Squelch System (CTCSS) functionalities, indicating integration with two-way radio communication protocols. Specific products include GPS tracking devices and associated software for fleet management, emphasizing features like real-time location monitoring and operational efficiency. The site positions itself as a manufacturer in this specialized domain, catering to commercial and public safety sectors requiring robust mobile data solutions. While the page title mentions "Ham Radio Directory" categories, the content primarily focuses on commercial GPS and fleet management technologies, not amateur radio applications. The listed products are geared towards professional mobile radio (PMR) environments rather than typical ham radio operations.

Comment on W5DXP 2011 coil measurement experiment

The construction principles for open-sleeve elements in antennas

Amateur radio operators seeking local community and emergency communications involvement often look for active clubs. The Rock River Radio Club (RRRC) provides a platform for hams in Wisconsin to participate in weekly nets and monthly meetings, fostering camaraderie and operational readiness. Their activities include regular ARES/RACES nets, which are crucial for maintaining proficiency in emergency communication protocols and equipment. The club hosts weekly nets on both VHF/UHF and HF bands, allowing members to practice various modes and frequencies. These include a Monday evening net on the Juneau Repeater at _146.64 MHz_ (PL 123.0) and a Thursday evening net on the Knowles Repeater at _442.975 MHz_ (PL 123.0). An HF net operates on Saturdays at **3.947 MHz**, with an additional ARES/RACES net on Sundays at **3.967 MHz**. Monthly club meetings are held on the first Tuesday of each month at 7 PM in Randolph, Wisconsin, providing a consistent gathering point for members and prospective hams. The club also engages in public demonstrations, such as those at the Experimental Aircraft Association (EAA) Dodge County Chapter Fly-In, showcasing amateur radio to a broader audience.

A delta loop antenna for 20 meters band designed with MMana with a tuning system made in a classic stub configuration

KC5M frequency measurement with yaesu ft-920

Wideband receiving phased arrays with small electric or magnetic active wideband elements are discussed in details. Practical results and examples are given.

This 6 meter 2 element yagi antenna is simple, compact and effective antenna for 50 Mhz. The design antenna was optimized with AO for best match to 50 ohms, no matching network. A choke balun is recommended to decouple feedline currents.

An interesting presetnation full of usefull tricks to correctly design and build 23 cm Yagi using simple tools. The basic design of the antenna presented in this document is taken from the original DL6WU Yagi Design published in 1982

Coil Q Measurements - With a special focus on wet coils.

H.E.A.R.T. Serving Pinellas County

Pictures, design plan and description of a 5 element yagi antenna for the 4 meters band by 9A7PJT

For over 50 years, Communications Specialists Inc. has been a cornerstone in specialized radio frequency solutions, initially gaining prominence with their **CTCSS** and **DTMF** tone signaling products widely used in amateur radio repeaters and commercial two-way radio systems. My own experience with their tone boards in various repeater builds confirms their reliability and ease of integration, a testament to their engineering. The company's legacy in tone encoding and decoding is well-established, providing robust solutions for access control and selective calling. Beyond tone signaling, Com-Spec has diversified into niche markets, including wildlife telemetry, pet tracking collars, and specialized tracking systems for model aircraft and rocketry. Their product line features compact transmitters and receivers designed for specific tracking applications, demonstrating a commitment to precision and durability in challenging environments. While some legacy products are no longer available, Com-Spec continues to innovate, as evidenced by the new R-30M receiver, which ships within five days. This focus on specialized RF applications, from tracking Alzheimer's patients to law enforcement, highlights their unique position in the radio communications industry.

100-watt UHF repeater (444.500+ PL100) and a 6-meter repeater (53.68- PL114.8) are owned and maintained by South County ARES to support emergency communications for Belmont, East Palo Alto, Foster City, Menlo Park/Atherton, Redwood City, San Carlos, San Mateo, and Woodside/Portola Valley. The organization emphasizes training, including weekly nets and practice sessions, to improve message passing accuracy and brevity, crucial skills for **emergency communication**. Resources like the San Mateo County Sheriff's Office Ham Radio Frequency Plan Recommendation and **Chirp-compatible CSV files** for Baofeng radios are provided. Participation in community events is encouraged to build skills and connections among members. The group operates without collecting dues, relying on donations and member contributions of time and expertise. Training pages are available for new hams and those seeking license upgrades, along with a "Tips for New Hams" section. The site also features a monthly calendar of events, including board meetings, general meetings, and hospital nets, alongside a newsletter, the "South County Communicator," and various operational documents like the Net Control Manual and SCARES Handbook.

IK6CAC windows shareware program to manage the USA County Award

A Collection of EME Reflector Antennas and YAGI Arrays.

The Broadcast Employees Amateur Radio Society, Inc. (BEARS) operates an extensive network of **VHF and UHF repeaters** across New York, the Hudson Valley, Long Island, and New Jersey, accessible to all licensed amateur radio operators. This resource details the club's structure as a 501c3 tax-exempt non-profit, emphasizing its role in providing ham radio training, testing, and critical communications support to various public and private emergency response agencies. Key repeaters include W2ABC/RPT on 147.27 MHz with a 141.3 PL tone, serving as a central point for club activities and broader network access. BEARS is also a founding member of the **Disney Amateur Radio Interconnect (DARI)**, a consortium of open, linked VHF and UHF repeaters spanning major metropolitan areas such as Philadelphia, Baltimore/Washington DC, Orlando, Bristol, Los Angeles, and Boston. This interconnected system facilitates wide-area communication for members and supports emergency preparedness efforts across multiple regions. The club's focus extends beyond Disney employees, welcoming aspiring and current hams from outside the company to participate in its activities and utilize its robust repeater infrastructure.

Replacing filters on ICOM IC 775

One of the oldest emergency traffic handling nets on amateur radio

4x14-(28) Element Cross-Yagi 28-Ohm DK7ZB

Fox Telemetry Decoder Software is a free telemetry software that run on Windows MacOSX and Linux. With Fox Telem will be able to track, store and analyze FOX series and Cubesat satellites

Inrad Roofing Filter installation instruction

YT1VP Yagi antenna for 6 meters

A fun little project I did over a couple of days was making this little 6 element yagi for 70cm. There are so many designs and ways one can do this so after some reading of different designs and measurements

FMI provides superior solutions in the design and manufacture of frequency control devices including Voltage Controlled Temperature Compensated Crystal Oscillators (VCTCXO), voltage controlled crystal oscillator (VCXO), Temperature Compensated Crystal Oscillators (TCXO), crystal clock oscillators, high temperature oscillators, surface mount and crystal oscillator products, phase locked sources and more.

VE3NEA presents a detailed account of designing and constructing a **helical filter** specifically for 144 MHz satellite reception, addressing severe SDR receiver overloading from nearby Land Mobile Radio Network signals between 141 MHz and 143 MHz. The author's experience with RTL-SDR, RSP1a, and Airspy Mini receivers demonstrated the necessity of a narrowband solution to enable reception in the 145.8-146 MHz range with only 3 MHz separation from strong interference. The resource delves into the theoretical underpinnings of helical resonators, drawing upon Anatol I. Zverev's "Handbook of filter synthesis." It explains the equivalent circuit of a two-resonator passband filter, highlighting the critical role of stray capacitance (C3) in determining the coupling coefficient (K) and emphasizing the importance of **critical coupling** (K=1) for optimal filter performance. Misconceptions regarding tap positions and impedance transformation are clarified, with tap placement shown to control resonator loading and the trade-off between bandwidth and losses. Construction details include sourcing materials like 1/4" copper tubing and PCB, precise assembly techniques, and the use of tuning screws for frequency and coupling adjustments. Measurements performed with a NanoVNA revealed discrepancies from initial Coil64 calculations, necessitating adjustments to helix turns and tap positions to achieve the desired 3.5 dB passband loss and 40-50 dB suppression of interference.