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The Arrow Antenna is a design classic: it combines light weight, compact design and functionality in a single package for operating FM dual band satellites such as AO-27, UO-14, SO-41 and SO-50

The purpose of the APRS-Beacon is to provide simple APRS-compatible position beacons for up to three Objects. It is designed to 'stand alone' and does not monitor other traffic on the frequency. It can use a single-port TNC (in 'native' mode), a single- or dual-port TNC in Kiss mode or the AGW Packet Engine in order to transmit on up to four radio ports.(When running with AGWPE, APRS-Beacon will also work with Windows 2000)

A portable dualband dipole robust and compact antenna usable for horizontal and vertical polarisation by ON6MU

Article on the HF dual band antenna with construction details and how to add 160 meters to the HF2V

Dual Band VHF/UHF Slim Jim Antenna project

If you have a computer with word processing software and a printer, you can make your own custom QSL cards, with each card individually printed for the ham you just contacted. WA7S show you how.

FindU.com operates as a robust database archiving **APRS** (Automatic Packet Reporting System) data, including weather, position, telemetry, and message reports. It integrates data from both amateur radio APRS systems and the internet-based Citizen Weather Observer Program. This substantial 58 GB database is hosted on dual servers utilizing data replication, processing approximately 20 new reports per second to provide constantly updated information. The system supports various applications, such as displaying weather reports, tracking position data, and facilitating long-term vehicle tracking. A notable function involves forwarding over 100,000 near-realtime weather observations daily to the National Oceanographic and Atmospheric Administration (NOAA) for accuracy checks and use by NOAA and the National Weather Service. Additionally, it archives APRS reports from the International Space Station. Access to the database is primarily via dynamic web pages, with a comprehensive list of available CGIs detailed on a dedicated server page. While direct URL parameter editing is possible for advanced users, alternative web pages with forms simplify query submission. The platform utilizes **PNG** images for dynamic graphics, a choice made due to past GIF patent issues, ensuring broad browser compatibility.

Engaging in **QRP** operations, where amateur radio transceivers transmit at five watts or less, presents a unique challenge and satisfaction for many radio amateurs. This mode emphasizes efficient antenna systems, keen operating skills, and often, the art of **homebrewing** equipment to maximize performance under power constraints. Operators frequently utilize CW (Morse code) for its superior signal-to-noise ratio, enabling reliable contacts over long distances with minimal power. The VK QRP Club, formally known as the CW Operators' QRP Club Inc., serves as a focal point for Australian amateurs passionate about these low-power pursuits. The club fosters a community where members can share insights on antenna design, circuit construction, and operating techniques specific to QRP. It provides resources such as information on club nets and frequencies, Morse practice materials, and a platform for exchanging ideas among enthusiasts. Membership offers access to a network of like-minded individuals, promoting the continued development and enjoyment of QRP within the amateur radio hobby. The club's activities encourage experimentation and skill refinement, vital aspects of successful low-power communication.

Located in France, DXBeam designs and manufactures a range of monoband, dual band and triband antennas, rotary dipoles, Moxons and Yagis

The FTBVR5K software facilitates comprehensive memory management for the Yaesu VR-5000 scanning receiver, supporting operations such as modifying, moving, adding, deleting, masking, and unmasking individual memories. It allows for importing and exporting memory definitions via CSV files, sorting memories by frequency or name, and identifying duplicate frequencies within the receiver's configuration. The program also supports the creation and modification of bank definitions, management of PMS (Programmable Memory Scan) definitions, and adjustment of PMS scanning ranges. Additionally, users can print detailed reports of memories, banks, PMS definitions, rig settings, and S.CALL details, with visual cues like red highlighting for masked memories and yellow for the priority channel. FTBVR5K provides functionality to alter values within the VR-5000's Set and Config menus, and to change S.CALL station names and frequencies. The application operates on standard Windows PCs, including Windows XP, Vista, 7, 8, and 10, requiring an available COM port for transceiver connection, which can be a conventional serial port or a USB adapter. A minimum screen resolution of 800 x 600 is supported, with 1024 x 768 recommended for optimal usability.

Antenna was designed for SO-50 satellite operation but can be used for any VHF/UHF activity. It's a mix of a Moxon Antenna and a Yagi antenna. It has gains 4 dBd on 2m and 6.5 dBd on 70cm bands and it is fed via single 50 Ohm cable.

Restoring vintage amateur radio gear often presents challenges with accurate dial calibration due to the non-linear characteristics of analog tuning capacitors. This resource details the construction of a 100 kHz crystal calibrator, a crucial tool for precisely setting the frequency of older rigs lacking digital readouts. The design cleverly circumvents the scarcity and cost of 100 kHz crystals by utilizing a readily available 8 MHz microprocessor crystal, such as a _HC49U_ type, in conjunction with common _CMOS ICs_ like the 74HCT00 quad NAND gate and 74HCT393 dual 4-bit binary ripple counter. The circuit employs a two-stage frequency division process: the 8 MHz crystal oscillator output is first divided by 16 to yield 500 kHz, then further divided by 5 to achieve the desired 100 kHz output. A 5.1-volt Zener diode, _1N4733A_, regulates the power supply for the HCT series logic. The article also provides a modification to produce a 50 kHz calibrator by altering the counter reset logic. Installation involves feeding the output to the receiver front end, ensuring it's post-TR relay to prevent RF damage, and incorporating an ON/OFF switch for the 12V supply line.

A dual driven antenna for the 6 meters band.

Dual band vhf uhf dipole antenna by DL7JV

PA5DD version of the dual band yagi antenna for 50 and 70 Mhz

435 MHz double quad antenna by F5WN

OPCLOG provides a straightforward logging solution for amateur radio operators, enabling the systematic recording of contacts. The software primarily focuses on basic QSO management, allowing users to input essential contact details such as callsign, date, time, frequency, and mode. Its core utility lies in its ability to export log data in the _ADIF_ (Amateur Data Interchange Format) standard, which is crucial for interoperability with other ham radio applications and services. This ADIF export functionality facilitates the creation of personalized QSL cards, streamlining the process for operators who prefer custom designs over generic templates. The program's design emphasizes ease of use for individual station logging, rather than complex contest or DXpedition management. It offers a practical tool for maintaining a personal logbook, supporting the fundamental requirements for tracking contacts and preparing for awards. The software's simplicity ensures a low learning curve, making it accessible for operators focused on routine logging tasks.

A 144/440 dual band open stub J-Pole Antenna project by NT1K

glfer is a program for reception and transmission of QRSS/DFCW signals. It is composed of two main parts: the spectrogram window, where you can see the spectrum of the received signal vs. time the transmission functions, to emit cw characters at a slow but precisely controlled speed, using the QRSS (slow CW) or DFCW (Dual Frequency CW) modes

Over 15 years of experience in DXing and contesting informed the development of _DXHeat_, a responsive web DX Cluster and analytics platform. This service delivers real-time DX spots, accessible on both desktop and mobile devices, featuring intuitive filtering capabilities. Users can quickly narrow down spots by band, mode, or specific callsign, streamlining the search for rare DX or contest multipliers. The platform integrates data from various sources, including traditional telnet clusters, the Reverse Beacon Network (_RBN_), and _PSK Reporter_, offering a comprehensive view of propagation and activity. Beyond live spotting, DXHeat provides extensive cluster analytics for individual callsigns, allowing operators to research past activity and propagation trends. This deep dive into historical data can be particularly useful for planning future DXpeditions or optimizing contest strategies. The interface is designed for serious DXers, prioritizing quick access to relevant information and robust data analysis.

On this page is the design for Dual Band 2M / 70cm antenna with 3.2mm elements. The antenna has a 50 ohm designed driver. This Yagi has a unique element called a Open Sleeve

Circuit diagrams drake tr7, Schaltbilder Drake Tr7, antenna tuners, baluns, and home brew power supplies, dual tone ssb test generator, zweiton ssb test generator, zweiton testgenerator, dual tone test generator by DK4DDS

A dual band wire antenna project in Italian

Despite the title referencing the callsigns 3C5J and MW0BRO, the content of this resource focuses entirely on the _Cleddau Computer Clinic_, an IT services company operating in Pembrokeshire since 1999. The site outlines a broad range of computer-related services, including custom-built new PCs starting from £399, sales of used systems, and comprehensive repair and upgrade options for existing units. Services extend to anti-virus and spyware removal, system installation, and broadband connection setup. The clinic also provides tuition for hardware and software applications, website design, and video to DVD transfer. They specialize in both fixed and wireless network solutions, enabling clients to share files and broadband connections efficiently. Repairs can be conducted either in their workshop or at the client's home or office, offering flexibility. For situations where on-site repair is not feasible, the Cleddau Computer Clinic offers a temporary replacement computer service. This includes transferring essential data to minimize disruption, a practical approach for local businesses and individuals in areas like Pembroke, Milford Haven, and Haverfordwest.

A lower power desktop linear with integrated 120vac power supply. This, very compact, dual 811 version will deliver about 300 watts output. Covers all bands including WARC bands.

This online article provides a list of individuals who hold or have held amateur radio callsigns, detailing their public recognition. The resource identifies specific callsigns such as **K1JT** (Joe Taylor, Nobel Prize in Physics), **W6OBB** (Art Bell, syndicated radio personality), and **JY1** (King Hussein of Jordan), linking them to their non-amateur achievements. It also notes operational statuses like _Silent Key_ for deceased operators and _lapsed callsign_ for inactive licenses. The article includes information on callsign changes due to vanity callsign programs and provides examples of individuals involved in specific technical areas, such as Percy L. Spencer (**W1GBE**), inventor of the microwave oven, and Jay Kolinsky (**NE2Q**), inventor of electronic sirens. It also references amateur radio involvement in _space missions_ for individuals like Owen Garriot (**W5LFL**) and Helen Sharman (**GB1MIR**). DXZone Focus: Online Article | Famous Hams | Callsign Status | Vanity Callsigns

Examines various facets of online casino gaming, focusing on security, game selection, and payment solutions. It details the extensive gaming libraries offered by online casinos, which often feature over **4,500 games** from more than _75 top software providers_, including slots, live dealer games, and table games. The resource also covers stringent security standards, such as 256-bit SSL encryption and dual licensing from authorities like the _Malta Gaming Authority_, ensuring player fund segregation and data protection. Furthermore, the content explores diverse financial solutions, including traditional methods like Visa/Mastercard and modern options like Skrill, Neteller, and cryptocurrencies such as Bitcoin, with withdrawal times ranging from **0-6 hours** for e-wallets. It highlights mobile gaming experiences optimized for various devices using HTML5 technology, offering over 4,000 mobile-optimized games. The resource also delves into VIP rewards programs, loyalty benefits, and customer support channels, emphasizing quick response times.

This document details the design and construction of a Vinecom 6N4 dual-band Yagi antenna for the 50MHz (6-meter) and 70MHz (4-meter) amateur radio bands. The antenna features 9 total elements (4 elements for 50MHz, 5 elements for 70MHz) on a 4.236-meter aluminum boom. Computer simulations using MMANA software predict 7.21 dBd gain on both bands with front-to-back ratios of 16.01dB (6m) and 15.37dB (4m). The design uses 12.7mm diameter elements mounted on a 32mm square boom, weighing 5.7kg total. Practical measurements with an MFJ-269 analyzer confirmed good SWR performance across both bands after element length adjustments.

A homemade VHF/UHF vertical antenna made essentially with RG58 coax cable, with a 9 turns choke balun to prevent the shield acting as a RF Radiator.

The Collins TRC-75 autotune linear amplifier, owned by JF2SVU, is presented with a focus on its internal modifications. This QRO amplifier utilizes three 4CX250 tubes in parallel for its final stage, delivering 1 KW output power. Notably, the amplifier achieves full power with only 100 mW of RF input, a characteristic often associated with Collins designs. The original 400 Hz power supply has been converted for easier shack integration, and the entire RF and power supply sections have been rehoused into a compact, clean enclosure. The control unit, positioned above the amplifier, features three meters for individual vacuum tube IP monitoring and a multi-meter on the right. A dedicated 7 MHz receiver, recently completed, is also part of this integrated system. The autotune functionality means the main amplifier unit only requires connections for power, control, and coaxial cables, simplifying its operation. Key components like the 4CX250 tubes and NF capacitors are visible, along with the gearing mechanism for the final tank circuit. A timer and relay system manages high-voltage delay and cooling fan off-delay, although the cooling fan's airflow is noted as somewhat insufficient. A central volume control, which experienced a contact issue, is also highlighted.

The G5RV multiband HF antenna, designed by Louis Varney (G5RV) in 1946, is a popular compromise antenna offering good overall performance on most HF bands when paired with an external antenna tuner. The basic full-size G5RV measures 102 feet across the top for 80 through 10 meter operation and is fed at the center via a 34-foot low-loss feed-stub. This interaction between the radiating section and the feed-stub facilitates matching across 80-10 meters with a standard tuner, often eliminating the need for ladder line directly to the shack. The antenna's design center frequency is 14.150 MHz, configured as a 3/2-wave dipole on 20 meters, with its 102-foot length derived from long-wire antenna formulas. Construction details emphasize the matching section, which can be open wire, ladder line (window-type), or TV twin lead. Each type has a specific velocity factor (VF) affecting its physical length for an electrical half-wave on 14 MHz; for instance, open wire requires 33.7 feet (VF 0.97), ladder line 31.3 feet (VF 0.90), and TV twin lead 28.5 feet (VF 0.82). The article provides formulas for calculating these lengths and discusses the antenna's behavior on individual bands, from 3.5 MHz where it acts as a shortened dipole, to 28 MHz where it functions as two three-half-wave long-wire antennas fed in-phase. Practical construction notes include recommendations for vertical descent of the matching section, sealing the coax junction, providing strain relief, and winding a coaxial choke coil to mitigate common mode current. The resource also presents dimensions for double-size (204 ft) and half-size (51 ft) G5RV versions, along with their corresponding matching section lengths for various line types, making it a versatile reference for hams considering this classic wire antenna.

A VHF UHF 5+5 elements yagi antenna by CE4WJK

Many NDB radio enthusiasts publish their reception logs on the web. A completely separate system designed for individual listeners to make their own logs and obtain statistics on NDBs, DGPS and now Navtex Stations they have received. Log listings can be exported in a multitude of formats and then emailed to the NDB List

The Resonant Feedline Dipole (RFD) HF antenna design utilizes a single piece of coaxial cable and a stranded wire section, forming a 1/4-wavelength radiator. This configuration, based on a 1997 ARRL Handbook design (page 20.17), functions by RF traveling on the inside of the coax shield and returning on the outside, creating the second half of the dipole. A choke wound into the feedline prevents RF current from flowing back down the feedline. Construction details include using RG-58a/u coax for a 75m version, with a 1/4-wavelength section of stranded wire soldered to the center conductor. The document provides choke dimensions for RG-213, RG-8, and RG-58 coax across 3.5 MHz to 28 MHz, specifying cable length and number of turns. Dipole dimensions are also tabulated for frequencies from 3.6 MHz to 28.4 MHz, listing overall length and individual leg lengths. Field tests included deployment near Bryson City at 5 feet off the ground and as a sloper during WCARS Field Day in Asheville, yielding successful local and regional contacts.

Speaker Microphone Pin Out, Dual PTT Switching,Programming Cables, SMA Antenna Connection, Extended Antenna Threads for Baofeng UV 3, UV 5 Series handheld transceivers

The resource presents a detailed schematic for constructing a dual-band vertical antenna, specifically designed for operation on the 2-meter and 70-centimeter amateur radio bands. It illustrates the physical layout, critical dimensions, and component placement necessary for successful replication. Key elements such as the radiating elements, phasing sections, and feed point are clearly depicted, providing a visual guide for radio amateurs undertaking a homebrew antenna project. The diagram specifies the lengths for the VHF and UHF sections, indicating how these elements are integrated to achieve dual-band functionality from a single coaxial feedline. It also implies the use of common materials readily available to most experimenters, focusing on simplicity and effectiveness in its design. The visual format of a GIF image ensures direct access to the construction details without requiring extensive textual interpretation. This schematic serves as a practical reference for hams interested in building a compact, efficient vertical antenna for local and regional FM communications, offering a proven design for immediate implementation.

SecondHandRadio.com provides a platform for the amateur radio community to buy, sell, and swap used, surplus, and obsolete electronics and electrical equipment. The site facilitates transactions for a wide range of items, including ham radio transceivers, test equipment, shortwave receivers, antennas, and vintage radio components like tubes. Users can place classified advertisements with photos at no cost, catering to individuals, radio clubs, and commercial dealers seeking to liquidate or acquire gear. The platform emphasizes ease of use with a straightforward sign-up process and no associated fees or commissions for listing or selling items. It positions itself as a primary resource for used electronics within the USA, fostering a direct connection between sellers and buyers without intermediary charges. The service supports various categories beyond amateur radio, extending to military radios and antique equipment, thus serving a broad spectrum of radio enthusiasts and collectors.

The antenna is a VHF side is a 2m moxon, tuned on 145.825 MHz. The driven element of the moxon couples to a driven element for a 5 element 70cms Yagi, tuned on 436.5 MHz.

Package contain 1x yaesu vx-8r 1x sma dual section antenna 1x hf antenna lithium ion battery pack fnb-101li 1x battery charger nc-86c 1x connector unit

The original project of a dual band yagi antenna for 50 and 70 mhz, published on dubus 2/2007 by YU7EF

The webpage provides guidance on working 6 Meter DX, focusing on effective operating habits, preparation, and knowledge of the band. It emphasizes the importance of monitoring, clear frequencies, and using CW for weak signals. It also mentions the significance of knowing countries and individual stations on the air to increase chances of working DX. The page recommends utilizing resources like newsletters and websites to stay updated on 6-meter activity and offers suggestions for improving operating skills.

Demonstrates the construction and implementation of a **two-element phased vertical array** for 40 meters, utilizing _Christman phasing_ techniques. The author, W4NFR, details the process from building individual 1/4-wave aluminum verticals to integrating them into a phased system. The resource covers antenna spacing of 32 feet, elevated radial design, and the critical steps for tuning each vertical to achieve a 1.1:1 SWR before combining them. It also provides insights into calculating precise coax lengths for feedlines and the phasing delay line, emphasizing the use of an MFJ-269 Antenna Analyzer for verification. The finished system exhibits good front-to-back nulls, with an overall SWR ranging from 1.6:1 to 2.2:1, which is managed by an antenna tuner. The project includes detailed photos of the relay box, showing 12 VDC relays capable of handling 5KV, and the control box in the shack for switching between three different antenna pattern configurations. Static bleed-off chokes are incorporated for protection, and the construction emphasizes robust weatherproofing for outdoor elements.

A 2m 70cm Dual Band J-Pole antenna for 35 USD. An excellent performing J-Pole type antenna, constructed from readily available materials.

The 10-minute, 25-second video demonstrates making a QSO via the VO-52 amateur radio satellite, focusing on real-time Doppler shift correction. It features Simon, 2E0HTS, operating a Yaesu FT-847 transceiver and a homebrew dual-band Yagi antenna, specifically a 10-element 435 MHz Yagi for uplink and an IO Loop for 145 MHz downlink. The video visually details the operator's technique for continuously adjusting the uplink frequency to compensate for the satellite's changing velocity relative to the ground station, a critical aspect of successful satellite communication. The demonstration highlights the practical application of Doppler compensation, showing the operator tuning the transmit frequency to maintain a stable received signal from the satellite. This approach contrasts with systems employing automatic Doppler correction or full-duplex operation, providing insight into manual frequency management for satellite passes. The video serves as a direct, observational guide for hams interested in LEO satellite operations, particularly those using non-tracking, manually tuned setups.

If you can program split-frequency memories in your dual-band radio, or your dual-band radio has two VFOs, you can work an FM satellite

The antenna described here is a direct-connect dual-rectangle beam for use on 70 cm between 440 and 450 MHz

Dual phase coherent Software Defined Radio using two K2 Elecraft receivers and programming in Matlab/Simulink.

VHF UHF half wave flower pot antenna project by VK2ZOI

Crossband repeat operations on the Wouxun KG-UV8D dual band multifunctional two-way radio. This demo explains differences in the cross band repeater functions of the KG-UV8D.

Edwin H. Armstrong's foundational contributions to radio technology are presented, including the _Regenerative Circuit_ (1912), the _Superheterodyne Circuit_ (1918), the Superregenerative Circuit (1922), and the complete FM System (1933). This resource functions as a curated collection of historical documents and artifacts, many previously uncirculated, stemming largely from the _Houck Collection_. The site's purpose is to offer these primary source materials for study and enjoyment, rather than to retell Armstrong's life story, which is covered in works like Lawrence Lessing's "Man of High Fidelity" and Tom Lewis's "Empire of the Air." The collection emphasizes original documents, photographs, and equipment, all sourced from the Houck Collection unless explicitly noted otherwise. The site is structured for browsing chronologically, by selected year, or by highlight, allowing users to explore Armstrong's technical evolution. Document files are intentionally large to preserve readability and detail, while individual pages are kept concise to optimize loading times. The content provides direct insight into the technical development of radio communications.