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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.

Vapex Tech offers over **150 different battery products** tailored for diverse applications, including specific models for Icom, Kenwood, and Yaesu handheld transceivers. The product catalog details specifications for NiMH, LiPo, and LiFePO4 chemistries, providing crucial data on voltage, capacity, and discharge rates. Customers can browse by application, such as _Airsoft Batteries_ or _Model Control Batteries_, or directly by consumer battery types like AA and AAA cells. The resource presents a structured e-commerce platform where users can filter products by category, view detailed item descriptions, and proceed with online purchases. Each product listing includes high-resolution images and key technical parameters, enabling informed selection for specific radio equipment. Operational hours are clearly stated as 9am-5pm Mon-Fri and 9am-12pm Sat, with contact information including a sales email and phone number for direct inquiries. The site also features a "Latest News" section, indicating ongoing updates regarding product availability or company information.

The _Nomenclature Française_ offers an online callbook service specifically for French amateur radio operators and SWLs. This resource facilitates searching for stations by various criteria, including callsign, operator name, city, and postal code. Search results typically display the operator's identity, full address, email contact, and personal website link, if available and publicly listed. The platform serves as a central database for the French amateur radio community, maintained by the _REF Union_. It provides a direct mechanism for operators to request modifications or new insertions of their data into the online nomenclature, ensuring current and accurate listings. The service is a fundamental tool for QSLing, locating fellow hams, and verifying contact information within France. Authored by _F6BIG_, the callbook is a key utility for French hams.