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QTH.COM offers a comprehensive platform for amateur radio enthusiasts to buy, sell, and trade equipment. This online service is designed to facilitate transactions between hams, allowing users to list their gear for free. Whether you're looking for HF or VHF equipment, antennas, or even vintage radios, QTH.COM serves as a hub for all your ham radio needs. The site is user-friendly and accessible, making it easy for both seasoned operators and newcomers to navigate the listings. In addition to individual sellers, QTH.COM also attracts dealers and manufacturers looking to reach a wider audience. With a diverse range of categories, including military radios and radio tubes, users can find unique items that may not be available elsewhere. The platform's commitment to providing a free service ensures that all hams can participate in the marketplace without financial barriers. Join the community at QTH.COM and discover the best deals in the ham radio world.

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.

For over 20 years, bhi Ltd has specialized in digital signal processing (DSP) technology to mitigate noise and interference across various radio channels. Their product line, including the _ParaPro EQ20 Audio DSP_ units, focuses on enhancing receive audio quality, even for operators without significant noise issues, by offering precise parametric equalization to suit individual hearing preferences. The core offerings are noise-cancelling speakers and in-line modules, specifically engineered for amateur radio applications, but also adapted for commercial, PMR, and marine radio systems. The company provides audio demonstrations, such as a 20m SSB example and a 14MHz band filter comparison, allowing users to hear the effectiveness of their DSP units against common QRM sources like plasma TV interference or diesel engine noise. Located in Burgess Hill, West Sussex, UK, bhi Ltd emphasizes clear voice communications, aiming to remove unwanted noise and leave only intelligible speech.

Manually programming D-Star handheld transceivers like the _Icom ID-51A_ and _ID-31A_ can be a straightforward process, enabling operators to configure repeaters, simplex frequencies, and D-Star specific settings without relying on computer software. This method is particularly useful for field operations or when quick adjustments are needed, allowing hams to set up callsign routing, DR mode, and reflector links directly from the radio's interface. Understanding the menu structure and key sequences is crucial for efficient on-the-fly programming. Operators often find manual programming invaluable for activating new D-Star repeaters encountered during travel or for participating in local nets where specific G2 or G3 gateway configurations are required. While software like _CS-51_ offers convenience for bulk programming, the ability to manually input frequencies and D-Star parameters ensures operational flexibility. This approach also helps hams troubleshoot connectivity issues by verifying individual settings directly on the transceiver, ensuring proper D-Star registration and gateway access.

Marshall G. Emm, N1FN, meticulously examines iambic keying, dissecting its historical introduction in the late 1950s with transistorized electronic keyers and its purported advantages. The resource defines keying systems, electronic keyers, and various paddle types, including single-lever and dual-lever paddles, clarifying the distinction between iambic keyers and the iambic sending technique itself. It details the two main types of squeeze keying: true squeeze for alternating dot-dash strings and character insertion for specific elements within a character. N1FN critically evaluates the actual efficiency gains of iambic keying, referencing Chuck Adams, K7QO's, keystroke analysis. While a straight key to bug transition yields a 34.1% reduction and a bug to non-iambic keyer offers 16.1%, iambic keying provides only an 11% theoretical improvement. However, considering typical QSO text and Morse code's inherent optimization for common letters, the practical efficiency gain is estimated at a modest 4-6%. The article also highlights how iambic keying's reliance on precise timing gates can impose a speed limit, making it less effective above 40 WPM, where many operators revert to non-iambic methods or single-lever paddles.

715 days, 6 hours, 58 minutes, and 29 seconds of uptime are reported for the YSFReflector-Dashboard by DG9VH, which monitors the IT C4FM SUD / ITALY-SUD reflector. This dashboard, compiled on December 1, 2017, provides real-time operational statistics for the reflector, including system information, disk usage, and connected YSFGateways. The dashboard also features a "Last Heard List" and an "All Heard List," displaying callsigns, durations, and timestamps (Europe/Rome) of stations active on the reflector. These lists offer a quick overview of recent activity, which can be useful for tracking **C4FM** traffic. While the resource is titled "IZ7AUH-6 DX Web Cluster," the primary content displayed is a **YSFReflector** dashboard. This suggests the platform might serve a dual purpose, offering both traditional DX cluster services and monitoring for Yaesu System Fusion reflectors.

Approximately 100 MeshCom nodes are visualized in real-time on a geographical map, providing a dynamic overview of the LoRa mesh network. This resource, hosted by _OE1KFR_, details node positions, telemetry data, and message traffic. Users can measure distances between two selected nodes, view text messages with callsign, destination, and gateway information, and access position data including latitude, longitude, and altitude. The platform supports filtering by regions such as Europe, USA, and Asia, allowing operators to focus on specific geographical areas. The detailed node list table presents comprehensive status information for each node, including gateway callsign, firmware version, hardware type, and environmental telemetry like temperature, pressure, humidity, and CO2 levels. This granular data enables operators to monitor network health and individual node performance, facilitating troubleshooting and optimization of MeshCom deployments. The map interface enhances situational awareness for those engaged in LoRa mesh networking.

The **5-Port 12 Volt DC Power Strip Kit (Rev 4)** offers a practical solution for managing shack power distribution, providing one input and five fused outputs. All connections utilize the ubiquitous Anderson PowerPole connectors, a standard for many amateur radio operators, ensuring a clean, organized, and safe way to power multiple 12 VDC transceivers and accessories from a single source. This design mitigates the common issue of tangled wires and overloaded connections in a typical ham shack. Rated for a maximum current of 20 Amps at 12 VDC, the strip incorporates an integrated LED to indicate when external power is applied. Each output is individually fused, a critical safety feature that protects connected equipment from overcurrent conditions without affecting other devices on the strip. This level of protection is essential for preserving sensitive radio gear during operation. Assembly requires basic soldering skills and hand tools, with a high-power soldering iron and wide chisel tip specifically recommended for best results. The kit's compact dimensions of 4.13" x 1.78" allow for flexible mounting via screw holes, making it suitable for various shack configurations and portable operations.

The project aims to create a remote control system for the VK5RSE beacons located near Millicent, South Australia. The beacons on 144.550, 432.550, and 1296.550 MHz can interfere with nearby amateur radio operations, particularly for EME work on 1296 MHz. The remote control system uses a DTMF decoder and PIC microcontroller to allow turning the beacons on and off individually or in combination. The system is housed in a diecast box and powered from 5-8V. The password-protected control allows authorized users to manage the beacon operations remotely, helping mitigate interference issues for local amateurs.