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Repairing and restoring a Yaesu FL-2100Z amplifier

An Offset Attenuator for fox hunts.

Repairt a Heathkit SB-220 Linear Amplifier with a bad Plate Voltage meter

Antenna model for a diamond loop wire antenna for the 40 meter band

Presents the _K7AR DX NorthWest Web Cluster_, an online service for amateur radio operators to access real-time DX spots. The resource functions as a web-based interface, enabling users to monitor current band activity, identify rare DX stations, and track propagation conditions across various amateur bands. It aggregates spotting data, making it accessible without requiring a dedicated telnet client, thus simplifying access for many hams. The cluster integrates with the broader DX spotting network, offering a continuous stream of reported contacts. While specific performance metrics are not detailed, such web clusters typically update spots within **seconds** of submission, providing timely information crucial for DXing and contesting. Its utility lies in offering a quick, browser-based overview of the airwaves, comparable to traditional telnet clusters but with enhanced accessibility.

A simple 50 ohm dummy load to test transmitters. includes a simple RF diode detector to measure the peak voltage, and calculate the power

An homebrew project for a 4 elements yagi monoband antenna for the 10 meters by 9M2MSO

low-noise amplifier for HF reception, amplifies signals 80 to 100 times between 0.15 MHz and 30 MHz. It will let you hear more signals with your RTL-SDR plus Ham-It-Up setup

Examining the _Angle of Radiation_ and its impact on amateur radio operations, the resource provides insights into optimizing antenna performance for DX and local contacts. It features a design for SPOTTO, a direct conversion high-performance universal DSB transceiver, detailing its construction and operational characteristics for homebrew enthusiasts. Additionally, the site presents a 7-element VHF high-gain antenna design, offering practical schematics and expected performance metrics for those seeking enhanced gain on VHF bands. The resource also covers the development and popularity of the _FT8_ digital mode, highlighting its effectiveness in weak-signal conditions and its role in special event operations like the FT8DMC anniversary. It includes information on Hamfest India 2023 and the Lamakaan Amateur Radio Convention, providing dates and organizational details for significant Indian amateur radio gatherings. Technical articles on Direct Digital Synthesizers (DDS) VFOs and low-cost multifunctional frequency counters offer practical project ideas for radio amateurs.

A review of the Yaesu FT-857D mobile transceiver by yo3hjv

An omnidirectional and horizontally polarized VHF antenna by EA4EOZ

Delta loop antennas for 40 meters plans and comparison of some models

Installing a classic G5RV Antenna in Slopinv-V mode by AI4WM

HF DX Web Cluster from JAPAN show spots by JA stations

The HF horizontal loop has been around for many years now. This article includes a YouTube video and discusses the reasons for looking at this antenna, its design, and its installation. There are some on-air comparisons against three regular double bazooka (coax) dipoles and the Par SWL End-Fed antenna.

This is a one for all antenna tuner with wide range tuning on all the HF bands. The tuner is based on a G3WQW design. DIY project by PD7MAA

The NG7M Web Cluster, maintained by W7CT and NG7M, offers real-time DX spotting information crucial for amateur radio operators engaged in DXing and contesting activities. This service aggregates DX spots from various sources, presenting them in a user-friendly format accessible via both web interface and traditional telnet protocols. Operators can monitor band conditions, identify rare DX entities, and track propagation paths across multiple amateur radio bands. This cluster supports a wide range of operating modes and bands, facilitating efficient station operation for both casual DX chasers and serious contesters. The system integrates data from the Reverse Beacon Network (RBN) and PSK Reporter, enhancing its utility by providing automated CW and digital mode spots alongside manually entered voice spots. Access methods include a direct web interface for graphical display and a telnet connection for command-line interaction, catering to different operational preferences. The cluster's data stream is continuously updated, ensuring timely information for making critical operating decisions.

Heathkit SB 220 mods, replacing the Zener ZD1, replacing the plate-voltage voltage divider, adding a keying circuit for solid state transceivers

The Speaky HF SSB transceiver and other homebrew projects Homebrew of radio equipment, antennas, tuner, etc.

A post about the construction and measurements of a Resonant Feedline Dipole cut for the 10M band

The page discusses the concept of a 2-element Parasitic Ground Plane antenna for the 40-meter band. It includes a conversation between amateur radio operators discussing modeling results and design considerations for the antenna. The author shares insights on radial configurations and the impact on antenna efficiency and pattern.

Shortwave listener blog from near Rome Italy

Improve the stability of your Yaesu G-250 rotator.

A morse keyer project made on Arduino, inlcudes the main program script by m0xpd

Personal SWL log with various information from SWL tips and tricks to Frequecy Logs to general SWL information.

Presents construction details for Moxon antennas, specifically focusing on 10-meter and 17-meter band configurations. It covers practical aspects of building these directional wire arrays, including element spacing, feedpoint considerations, and material choices for optimal performance. The resource emphasizes homebrewing techniques suitable for amateur radio operators. Discusses the advantages of the Moxon rectangle design, such as its compact footprint compared to a full-size Yagi and its favorable front-to-back ratio. It provides insights into achieving proper impedance matching and structural integrity for portable or fixed installations. The content includes photographic examples of constructed antennas. Explains the iterative process of tuning and optimizing Moxon antennas for specific frequency segments within the 10m and 17m bands. It offers guidance on minimizing SWR and maximizing gain, drawing from real-world building experiences to assist constructors in replicating successful designs.

Notes about generating RF sweep signals on the Arduino for filter testing, a digital version of the old Wobbulator concept

This circuit enables fair copy of strong 444 MHz signals, off a local repeater, using a 2m rig and a 1/4λ 70 cm indoor ground plane antenna.

Cushcraft A3S HF antenna 1:1 balun repair.

Operating magnetic loop antennas requires careful consideration of RF safety, particularly regarding near-field magnetic field intensity. This resource presents calculations for magnetic field strength (H-field) at various distances from a magnetic loop, emphasizing that the H-field is significantly higher than the E-field in the near-field region due to the inductive nature of the radiating element. It provides specific formulas and examples for determining safe operating distances based on power levels and loop dimensions, crucial for compliance with RF exposure limits. The analysis compares calculated H-field values against FCC and ICNIRP maximum permissible exposure (MPE) limits for controlled and uncontrolled environments. It demonstrates that even at QRP power levels (e.g., 5W), the H-field can exceed MPE limits within a few feet of the antenna, necessitating greater separation distances than often assumed for electric field considerations. The practical application of these calculations helps amateur radio operators configure their stations to ensure personnel safety and regulatory compliance when deploying compact, high-Q magnetic loop antennas.

Sporadic-E clouds location and estimated MUF real time map

Articles about Amateur Radio, own writings and translations: history, DXpeditions, contesting and DXing ethics, Codes of Conduct, Suggestions for Pile-ups, Suggestions for Contesters, the most wanted DXCC entities.

This antenna article is geared towards new Hams and antenna builders looking for a very inexpensive 6 band antenna that can be efficiently fed with 50 ohm coax without a tune

Adam Brown's Blog from Latitude 80.19 South Longitude 81.16 West

Presents the Holy Cluster, a contemporary DX cluster service offering real-time amateur radio spot data. This platform integrates a dynamic graphical map to visualize current contacts, enhancing situational awareness for DXers and contesters. Developed by an Israeli group of developers and supported by the Israeli Association of Radio Communication (IARC), the Holy Cluster aggregates DX spots from various sources, including traditional telnet clusters, the Reverse Beacon Network (RBN), and PSK Reporter, providing a comprehensive view of band activity. The cluster's design emphasizes a user-friendly interface for monitoring DX activity across multiple bands, including dedicated support for JOTA (Jamboree On The Air) operations. Its aggregation capabilities allow operators to quickly identify propagation openings and active stations, streamlining the process of making two-way radio contacts. The integration of RBN and PSK Reporter data offers insights into propagation conditions and station reception reports, which can be invaluable for optimizing antenna direction and operating strategies.

A fully equipped amateur radio mobile radio shack by VE6AB

Stop common-mode current when transmitting with an end-fed antenna. Unbalanced antennas are very prone to currents on the outside of the coax.

How to receive JT-65 signals using a cheap RTL-SDR dongle with the 820T2 tuner chip

PZTLog is a freeware amateur radio logging application designed for Windows operating systems, facilitating rapid **QSO entry** and management. It integrates features such as DXCC statistics tracking, a built-in DX Cluster client, and support for various digital modes including PSK31, PSK63, PSK125, and RTTY. The software provides a straightforward interface for inputting essential contact details and supports real-time interaction with DX spotting networks, enhancing the operator's situational awareness during operating sessions. The application's utility extends to contest logging, offering a streamlined approach for competitive operating. PZTLog's capability to manage **DXCC awards** and integrate with digital mode operations positions it as a versatile tool for general logging and specific contest scenarios. Its design prioritizes ease of use for quick data entry, making it suitable for operators who require efficient logging without extensive configuration.

Presents the construction of a 2-meter **Skeleton Slot Yagi** stack, detailing the design process and practical considerations for VHF operation. The author shares insights from building and testing this antenna, emphasizing its performance characteristics for local and extended range contacts. The project outlines the specific dimensions and materials used, providing a clear path for other radio amateurs to replicate or adapt the design for their own stations. The resource covers the unique aspects of the Skeleton Slot radiator, explaining how its geometry contributes to gain and pattern control. It includes discussions on impedance matching and feedline considerations crucial for optimizing power transfer and minimizing SWR. The article draws on real-world testing, offering practical results that validate the theoretical design. This project serves as a valuable reference for those interested in custom VHF antenna solutions.

The latest info on the world of radio including:world,shortwave,pirate,digital,mw,lw news,links.

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

An homebrew project of a full wave delta loop antenna for the 40 meters band with dimensione, picture and assembling instructions in Indonesian

KD8KSB realization of the CJU satellite antenna that allow similar performance to the arrow antennas.

Pictures and description of a homemade 1.3 GHz and 2.4 GHz RF Signal Source

A wire antenna feeded with an unsymmetrical feed and a 1:4 balun can be tuned from 6 to 80 meters band but can be noisier than a dipole and cause RF in the shack

Monitoring real-time amateur radio activity is essential for DXers and contesters seeking rare contacts or tracking propagation. This online service aggregates DX spots from various **DX Cluster** networks, presenting them visually on a world map. Users can observe new spots as they appear, facilitating quick identification of active stations and potential openings. The platform offers filtering capabilities, allowing operators to narrow down displayed spots by specific bands such as 160m, 80m, 40m, 20m, 10m, and even VHF/UHF segments like 70cm and 23cm. Further refinement is possible by selecting the source continent of the spotter or the continent of the DX station, which assists in strategic operating. The service also includes a "Hot Now" list, highlighting currently active stations with recent spots. This dynamic display supports informed decision-making for pursuing **DX contacts** across different bands and geographical regions.

An comprehensive article on 40 meters antenna comparing vertical height to the resulting gain

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

Homebrewing dummy load by M0XPD