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In this article K3DAV show a very simple way to make an RF choke coil that will remove your RF feedback troubles

How to build a lightweight amplifier that can be backpacked around.

KJ4WLH homemade dipole for 50 Mhz

This handy and cheap portable dipole can be folded and backpacked, carried in use, and adjusted to a very wide range of frequencies by KV5R

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.

Green that aluminum into something useful right in your own backyard by WB2CQM

Negative feedback is often referred to as shunt feedback in conjunction with emitter degeneration.

Examines the Icom IC-2100H 2-meter mobile transceiver, detailing its operational characteristics and user experience. The review highlights the clear, easy-to-read display with internal labels, the button-filled microphone's functionality, and the rig's physical construction, including its weighty heat-sink and lack of a cooling fan. It also discusses memory programming, the unique amber-to-green backlight color options, and the radio's performance against _intermodulation_ in urban environments, noting it performs "pretty darn good" compared to other rigs. The analysis delves into a significant low-voltage cutoff problem, where the microphone ceases to function below approximately **12.6 VDC**, rendering the radio receive-only or causing it to stick in transmit. The author describes testing the voltage cutoff, observing it fluctuate from _12.38 VDC_ to 12.69 VDC. An update from Icom involved a "factory update" to the CPU's control code, which is strongly recommended for early-serial number units to prevent operational failure in low-power emergency scenarios.

Specialist in the design and supply of Radio Communications Equipment and Systems. West Sussex England. Antennas, traps and baluns inline isolators, Outbacker Antennas, Mobile Mounts and Accessories

The County Hunting software, version **6.1**, is designed for amateur radio operators focused on USA-CA Award tracking and logging. This application supports _Windows_ environments and facilitates the import and export of ADIF files, enhancing QSL management by integrating electronic confirmations via LoTW and e-QSL. The software has been updated to align with the new award rules managed by MARAC, following the discontinuation of CQ magazine's involvement. Users can visualize QSLs post-scanning and benefit from enhanced ADIF import functionality. Version 5.4 introduced accelerated county searches via FCC databases, with filters for QSL confirmations and e-QSL enhancements. The software also includes a feature for backing up and restoring QSOs by LoTW confirmations. Visual County tools have been refined, offering improved map interactions and the addition of county flags. The software supports various digital modes including FT8, FT4, and SSTV, and includes functionality for PSK250 and 60m bands. The application is multilingual, with support for Italian, English, French, and Spanish, and provides automated updates and web-based county searches. DXZone Focus: County Hunting | ADIF | Windows | LoTW

In his back office section, ON4SKY, initiates in a few articles the beginners in the art of QSLing and award chasing.

Largest Capacity of 200,000 MT for Towers & market leader in India with backward integrated rolling & manufacturers of Shelters, V/UHF, Patch Panel Antennas, DIAS & DWDM Equipment

Dealer for Alpha Delta hf antennas, switeches, Outbacker and super antennas, morse code keys, coax cable and military products, managed by W8GEG from Medina Ohio

This page presents a curated list of individuals who have made significant contributions across various fields while also being active amateur radio operators. For instance, Dr. Joseph H. Taylor, co-winner of the 1993 Nobel Prize in Physics for the discovery of binary pulsars, is recognized for developing the _WSPR_ and _WSJT_ weak signal mode software. Similarly, Wilson Greatbatch, inventor of the cardiac pacemaker with over **150 patents**, is featured. The resource details the diverse backgrounds of these hams, from Professor Donald H. Menzel, an astrophysicist at Harvard, to Hiram Percy Maxim, often called "The Father of Amateur Radio," who also pioneered in the automobile and aviation industries. King Hussein of Jordan, JY1, is noted for his active participation on 20 meters, engaging with fellow amateurs like Pat Kilroy, WD8LAQ. Other entries include Arthur M. Young, designer of Bell Helicopter's first model, and Marlon Brando, KE6PZH/FO5GJ, known for operating from his private island in French Polynesia. Peggy Sue Gerron-Rackham, K5PSG, gained her license after a special event station, demonstrating the hobby's broad appeal.

The North East Weak Signal Group (N.E.W.S.) website serves as the digital hub for an ARRL-affiliated regional club dedicated to _weak signal_ work across the VHF, UHF, and SHF spectrum, from 50 MHz up to light. It provides essential information for members and prospective enthusiasts, including the club's constitution and by-laws, details on officers and the board of directors, and a calendar of meetings and events. The site also features an application for membership, information on dues, and a membership roster, fostering a sense of community among its over 100 members. A significant feature of the site is its extensive archive of conference papers, including proceedings from the _Eastern VHF/UHF/Microwave Conference_ dating back to 2009. These papers cover a wide array of technical topics relevant to weak signal operations. The site also lists _50 MHz Beacons_ and _144 MHz and up Beacons_, along with links to other VHF and above resources, providing practical tools and knowledge for operators interested in pushing the boundaries of amateur radio communication.

Lightweight keys and paddles may be great for backbacking, but what if all you want is the darn thing to stay reasonably still on the desk?

Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.

One hundred and fifty words per minute (WPM) is a configurable speed setting in this online Morse code translator, which facilitates bidirectional conversion between plain text and **Continuous Wave (CW)**. Users can input text to generate corresponding Morse code, or enter Morse code using dots and dashes to receive a text translation. The tool supports various alphabets, including Latin, Cyrillic, Ukrainian, Hebrew, and Arabic, broadening its utility for international communication. The platform offers multiple output methods for the generated Morse code, including audible playback, visual flashing, and device vibration. Advanced configuration options allow for precise control over the sound's pitch (frequency), volume, and overall speed, including a **Farnsworth speed** setting. This flexibility enables users to customize the learning or communication experience to their specific needs. Additional features include the ability to save the generated Morse code audio as a WAV file and to create shareable links for messages, which can be sent with or without the accompanying text. The interface is entirely web-based, built with HTML5 and JavaScript, ensuring broad compatibility across modern browsers.

My Top Five Backyard Multi-Band Wire HF Antennas. A selection of the top 5 HF wire antennas for the backyard and for multi-band operation

Call Book Log 3.0 is a web-based logging solution for amateur radio operators, designed for self-hosting on a web server with MySQL/MariaDB and PHP 7+ support. It provides a mobile-friendly interface for viewing, adding, editing, deleting, backing up, and restoring QSO logs. The software features a streamlined setup process, allowing users to quickly deploy a personal logging system accessible via any web browser. Key functionalities include displaying the last **5** contact dates for previously worked stations, enhancing log management by providing immediate historical context during QSO entry. The system also includes a central administrative section for authenticated users to manage log entries. The 3.0 version represents a significant code overhaul, focusing on improved performance and a more *visually appealing* user experience compared to earlier iterations. Enhancements include better pagination, a redesigned menu with icons, and color-changing rows for improved readability. The add log page now incorporates a one-click time update feature, addressing user feedback regarding time synchronization during rapid QSO entry. This iteration builds upon previous versions like 2.1, which corrected an automatic _UTC date_ bug, and 2.0, which featured a full rewrite to resolve browser quirks and optimize search functions. The software's evolution demonstrates a commitment to functional stability and user interface refinement.

ECONCO has been rebuilding vacuum tubes for more than 30 years. Our commitment to quality, and concern for the environment has won us the acclaim of clients worldwide.

This resource provides a detailed historical record of satellite downlink frequencies, systematically organized by both frequency range and the satellite's launch year. It presents extensive listings covering segments from 8 MHz to 9000 MHz, including specific breakdowns like 136-137 MHz and 1600-2200 MHz. The data is segmented into distinct frequency blocks, offering granular information for various bands. The content delineates frequencies for satellites launched across several decades, with specific sections for years such as 2004, 1999, and extending back to 1967. This chronological organization allows for tracking the evolution of satellite communication frequencies over time. The resource serves as a reference for identifying operational downlink frequencies of historical space assets, which is particularly useful for satellite enthusiasts and those interested in _space tracking_ or _vintage satellite_ communications. The utility of this compilation lies in its specific historical data, providing a unique perspective on past satellite operations and frequency allocations.

Noise eliminating products. Remove unwanted background noise and interference leaving only the speech. Clear communications, listen stress free. Dsp noise cancellation solutions.

Accurate frequency measurement is crucial for amateur radio operators, particularly when building or troubleshooting transceivers and test equipment. This resource details the construction of a _PIC microcontroller_-based frequency counter, providing a practical solution for precise frequency display. The design incorporates an LCD readout, offering clear visual feedback of measured frequencies. The counter can operate as a standalone unit, useful for general bench testing, or be integrated directly into a receiver. Its built-in offset functionality allows for seamless integration, enabling the display of the received signal frequency rather than the intermediate frequency. The project focuses on accessible components and construction techniques, making it suitable for homebrew enthusiasts. Key features include a measurement range up to **50 MHz** and a compact form factor.

VE1FQ, has a long history dating back to 1932 and may be the oldest Amateur Radio club in Canada.

This resource presents a domain name for sale, specifically _Kl7aa.com_, for $995, with an option for a 24-month payment plan at $41.46 per month. The page details the purchasing process, including immediate domain access, zero percent financing, and secure shopping. It also outlines the transfer process to other registrars like _GoDaddy_, clarifies what is included with the domain purchase (only the domain name, not hosting or web design), and explains how to maintain WhoIs privacy protection. The content includes testimonials from buyers like Dann Berg and Greg Shepard, highlighting smooth transactions and quick domain delivery. It also provides information on HugeDomains' 30-day money-back guarantee and frequently asked questions regarding domain transfers, access post-purchase, and payment plans. The page emphasizes the importance of a web address and lists other similar domains for sale, such as _Kl35.com_, alongside quick stats about the domain's length and structure.

The K-Com website, originally intended for RFI rejection products, currently hosts content for a Nigerian football betting platform. The site promotes wagering on live EPL, NPFL, and UCL matches, offering competitive odds and instant OPay and bank payouts. It highlights features such as a **99 sign-up bonus** for new players, daily deposit rewards, and VIP cashback, alongside a mobile-friendly interface and NLRC licensing. The platform provides a demo hall with _1,000,000 demo credits_ for guest players to test strategies without registration. It emphasizes secure and reliable gameplay, instant withdrawals, and multi-game access, claiming over 100,000 active players. The content includes user testimonials and an FAQ section addressing game access, registration, promotions, and mobile compatibility, but contains no information related to amateur radio or RFI filters.

This resource presents a domain name for sale, Grandicelli.com, which was previously associated with an HF-VHF-UHF-SHF digital monitoring site, Wavecom Decoder tools, Winradio and DRM decoders, a WD3000 Direction Finding System, Radioraft software, and a PFSL3000 Integrated HF-VHF-UHF signal monitoring system. The current page functions as a sales portal, providing information on the domain's price of $695, with an option for a 24-month payment plan at $28.96 per month with 0% interest. The page outlines the purchasing process, including quick delivery of the domain within one to two hours, and details the transfer procedure to registrars like GoDaddy. It also highlights customer testimonials regarding the ease and speed of domain acquisition through HugeDomains, emphasizing the 30-day money-back guarantee and secure shopping experience. The resource clarifies that only the domain name is included, with hosting and web design services needing to be sourced separately.

Restoration and sale of quality antique radios that work, backed by professional testing, restoration, and warranty. vintage hi-fi included.

Pictures and description of a SteppIr vertical antenna setup in a small backyard using DX Engineering radial plates.

This resource provides a unique historical audio archive of 50 MHz DX contacts, documenting significant F2 and Es propagation events experienced by PA2S (formerly PA2HJS) since 1978. The collection includes recordings of beacons and two-way QSOs with stations across North America, South America, Asia, Australia, Europe, and Africa. Specific entries detail contacts with rare DX entities such as ZS6PW, VE1AVX, C5AEH, J52US, TR8CA, LU8MBL, VK8ZLX, and various Japanese stations, often noting the mode (SSB or CW) and propagation type. The archive also highlights challenging pile-up situations and frustrating near-misses during major openings. The recordings, initially in RealAudio format for solar cycles 21 and 22 and later in MP3 for cycle 23, offer a practical illustration of 6-meter band conditions over several solar cycles. The content allows hams to listen to actual signals from different continents, observing signal characteristics like typical TEP fading from 5H3RA or strong F2 backscatter from OZ1BVW. It provides a comparative perspective on propagation effectiveness between solar cycles, noting that cycle 23, while not as robust as previous cycles, still yielded interesting openings. The archive serves as a valuable educational tool for understanding real-world 50 MHz DXing and propagation phenomena.

An SSB radio for the HF bands will be presented. Featuring 12 to 20 Watts of output power (depending on DC supply), full DDS frequency generation, covering 6 major frequency bands (1.8, 3.5, 7, 14, 21 and 28 MHz) within the short wave amateur radio spectrum. The rig also features colored LCD and front panel backlight.

The NB6Zep Antenna, an electrically shortened 80-meter end-fed wire, addresses space constraints for low-band operation by integrating two loading coils into a 37-foot wire. This design, modeled with _EZNEC_, explores configurations like the quarter-wave sloper and inverted-L, with the latter providing a more vertical radiation pattern and practical backyard deployment. The resource details specific coil construction, recommending 21 uH coils made from _BW coil stock #3026_ or similar, and outlines wire segment lengths for optimal tuning. Performance analysis indicates a radiating efficiency of approximately 27% with good ground conductivity, resulting in a signal typically 3-4 dB down compared to a full-size quarter-wave vertical. The antenna exhibits a narrow bandwidth, around 50 kHz, due to its high Q, necessitating a tuner for broader band operation. Feedpoint impedance is low, with ground resistance playing a critical role in achieving a usable SWR. The article emphasizes the importance of an effective ground rod at the feedpoint for proper operation and tuning, suggesting an antenna analyzer for precise adjustments. It confirms the antenna's suitability for DX, citing successful contacts from Oregon to the East Coast and Hawaii on a 160-meter variant, making it a viable option for urban operators seeking low-angle radiation on 80 meters.

Six elements yagi antenna for 6 meters band. This antenna design is based on the QuickYagi 4 software by WA7RAI, uses a 6.5 m boom, feature 12.0 dBi gain and 35dB front/back

A no ground antenna solution for backpackers, balconies or plastic car bodies, like RV or other portables uses where is difficult to find a good counterpoise by PD7MAA

How to modify a Sky mini-dish so it will work effectivly at 2.4Ghz.

Super Antenna Systems for HF - VHF - UHF Portable Stealth Mobile Base Backpack EmComm Ham Radio antennas

Demonstrating the construction of a short dipole antenna tailored for the 60 meter band, this resource provides detailed instructions for radio enthusiasts with limited space. The design incorporates inductive loading using two inductors (L1/L2) made from PVC tubes, allowing for effective operation on 5 MHz. The antenna consists of 12 meters of wire, divided into four sections, with specific dimensions and materials outlined for optimal performance. Results from users indicate that this antenna can significantly enhance DXing capabilities on the 60 meter band. Feedback from operators suggests that while the design is effective, adjustments may be necessary based on individual setups, such as coil diameter and wire gauge. Many users report successful construction and operation, with some experimenting with variations to improve resonance. The practical application of this antenna design has led to successful contacts and improved signal quality, making it a popular choice among 60 meter band operators.

Practival project that contains two isolation transformers, one for AF from the tranciever to the line in on a soundcard, and one from the audio out of the soundcard back to the mic / data input of the radio. Both of which are variable inside the interface via two preset resistors.

Oakcallsigns.com specializes in custom-crafted oak call signs, presenting various designs for amateur radio shacks. The resource showcases different styles, including standard call sign plaques and options featuring iconic ham radio silhouettes like the _D-104_ microphone. Each item is described with pricing, ranging from $15.00 to **$25.00**, and includes details on shipping and seller reputation. The platform highlights the craftsmanship involved, emphasizing personalized scroll-saw work on each oak piece. It details the seller's positive feedback rating of **99.4%** from over 10,000 transactions, indicating a reliable source for these unique accessories. The site also provides information on the number of units sold for specific designs, such as 2,338 for the standard call sign gift and 554 for the smaller personalized version. This commercial offering focuses on decorative and personalized items for the ham radio enthusiast, distinct from operational equipment. It serves as a direct retail channel for custom shack adornments.

Taking the Raspberry Pi 2 for a Test Drive with GNU Radio. Installing GNU Radio and receiving aircraft radar with a USB TV tuner

Optimizing weak signal reception on the HF bands, particularly in the presence of strong local QRM, often necessitates specialized receiving antenna systems. This resource details the _HI-Z Antennas_ product line, focusing on phased vertical arrays designed for superior noise rejection and directivity. It covers components such as the 4-Square and 8-Element array controllers, which allow for rapid switching of receive patterns, and dedicated low-noise preamplifiers to improve system sensitivity. The site also presents various bandpass filters, crucial for mitigating out-of-band interference and enhancing the dynamic range of the receiver. The HI-Z systems are engineered to provide significant front-to-back and side rejection, often yielding **20-30 dB** of attenuation to unwanted signals, which is critical for DXing and contesting. Users can achieve a notable reduction in local noise, allowing for the discernment of signals that would otherwise be buried. The array controllers facilitate quick pattern changes, enabling operators to null out interference or peak weak signals from distant stations, effectively extending the reach of their receive capabilities by improving the signal-to-noise ratio.

Solar Power for Your Ham Station, It is Easier Than You Think QST article April 96 by KE0OG via Repeater-Builider.com

Presents the Scranton Pocono Amateur Radio Club (SPARK), K3CSG, highlighting its status as one of Pennsylvania's most senior ARRL-affiliated clubs. The club, also known as the Abington Amateur Radio Club, maintains a consistent presence in the local amateur radio community. It provides a platform for radio enthusiasts to engage in various aspects of the hobby, including operating events and technical discussions. The resource details the club's historical background and its ongoing commitment to fostering amateur radio interest and skill development among its members. The club's activities often encompass participation in field days, local nets, and support for emergency communications. Members frequently operate on HF and VHF/UHF bands, utilizing various modes for local and DX contacts. The club's callsign, K3CSG, is regularly active during club events and contests, representing its collective efforts in amateur radio.

Southeast New Hampshire W1SRA / 147.000Mhz / Negative Offset / 100.0 PL Tone Welcome to the Sunday Night Net each Sunday evening at 8:00 PM.

This handy and cheap portable dipole can be folded and backpacked, carried in use, and adjusted to a very wide range of frequencies.

Getting squeaks and squawks from your H-T? Are pagers crunching your mobile rig's front end? Here's how intermod happens--and how to fight back!

Presents the VHFDX.EU web cluster, a specialized resource for VHF, UHF, and microwave DX spotting. It details the cluster's functionality, including real-time spot aggregation and a DXCluster Map interface for visualizing activity. The resource highlights its integration with the MMMonVHF backbone, ensuring a robust data flow for monitoring band openings and propagation events across higher frequencies. It also references reviews of the ON4KST and N0UK chat systems, which are frequently used in conjunction with VHF DX operations. The platform offers a mobile-optimized view for on-the-go access to DX spots, catering to portable and mobile operators. It further provides daily ES (Sporadic E) spot summaries, a critical feature for VHF operators tracking this specific propagation mode. The cluster serves as a central point for operators to share and receive information on rare grid squares, contest activity, and general band conditions above 50 MHz.

Audio Repeater is a windows application tha allows you to transfer, transmit, sounds from an input audio endpoint or device to an output one Playback. Audio transfer can be performed in any PCM audio format supported by Windows. KS version communicates directly with audio driver, bypassing all additional Windows audio processing

Tape measurement yagi. The longest part is 530 mm, easy fit to your backpack. Very easy and fast deploy. Great for SOTA and portable operation. Can be used in horizontal or vertical polarization. Based on DK7ZB design