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High Voltage Supply for GS 35B Amplifier

Low power VHF RF amplifier with VMP1 Mosfet by IZ1BTS IK1XPD

A folded wire antenna for 160 meters as appeared on 73 amateur radio magazine june 1997

A vertical antenna project than can present low swr from 40 to 10 meters by using a balun in french

ARRL comparison of HF transceivers, including Elekraft, TenTec,Icom, Yaesu and Kenwood recent transceivers based on QST product reviews

This program displays solar-terrestrial data for radio waves propagation that is provided by the N0NBH web-service.

IC‐2300 MARS/CAP mod expanded frequency range 136‐174 MHz

This project was published in the April 2004 issue of the Australian magazine Amateur Radio, and has been designed using parts which are very readily available.

Ari Milano draw and keep updated these pdf files representing the "radioamatori" bandplan, with notes in italian

Diagram and sample ferrite balaun for 1.8-30 MHz

Understanding high-frequency (HF) skywave propagation is crucial for amateur radio operators seeking to optimize long-distance communications. This resource details the fundamental principles of HF radio propagation, including the properties of electromagnetic waves, the characteristics of various HF bands, and distinct propagation modes such as skywave, ground wave, and line-of-sight. It places significant emphasis on the ionosphere's pivotal role in refracting HF waves, explaining how solar activity directly influences ionospheric conditions and, consequently, propagation paths. The resource integrates real-time monitoring capabilities, featuring dynamic charts and data from DX clusters, WSPRnet, and the Reverse Beacon Network, which allow users to track current band activity and propagation conditions globally. It also delves into advanced topics like Near Vertical Incidence Skywave (NVIS) and gray line propagation, providing insights into ionosonde data and various propagation prediction models. The site presents a detailed analysis of solar-terrestrial interactions, geomagnetic indices, and space weather phenomena, illustrating their direct impact on HF communication reliability. Practical tools and applications are highlighted, including real-time QSO planners, online Maximum Usable Frequency (MUF) maps, and alerts for solar flares or geomagnetic storms. The guide systematically breaks down complex concepts into accessible chapters, offering a structured approach to learning about ionospheric regions, diurnal and seasonal effects, and the interpretation of propagation indicators like foF2, MUF, and Lowest Usable Frequency (LUF). This makes it a robust reference for hams aiming to deepen their technical understanding and improve operational effectiveness.

Plans and drawings of common amateur radio antennas, like jpoles, copper cactus, super jpole, omnidirectionals and quads

This is the report of a MFJ-259B analysis of two 100 ohm / 5 watts resistors in parallel partially in italian

A 67 feet long dipole doublet antenna

All Band HF Doublet for operation over all HF bands including 160m.

Planning and modelling Delta Loop antennas for all the ham radio HF bands include calculated wire lengths at each mid-band

Transverter for 70MHz, a project by G3XBM

For radio amateurs seeking compact and efficient antenna solutions, particularly for restricted spaces or noise reduction, HF loop antennas present a viable option. This resource compiles several articles from the ARRL, detailing the theory, design considerations, and practical construction of various loop configurations. Topics include small transmitting loops, receiving loops, and multi-band designs, often emphasizing their performance characteristics such as directivity, bandwidth, and impedance matching. The collected articles provide insights into the comparative performance of different loop geometries, such as circular versus square loops, and discuss the impact of conductor size and tuning methods on efficiency. Practical applications are explored, including their use in portable operations, stealth installations, and urban environments where noise mitigation is critical. The content often includes construction diagrams, parts lists, and performance data derived from modeling or field tests, enabling hams to replicate or adapt the designs for their specific operating conditions.

Fractal antenna for 28 Mhz band by AG1LE

Working priciple of OSJ and jpole anntennas by PY4ZBZ

A multiband quarter wave vertical antenna that works on 5 bands.

A VHF power amplifier made with two cheap RF transistors, 2N3924 as driver and a BFS22A for final stage, giving an unexpected output power of 7-8 watts maximum

A comprehensive guide to receive Weather Satellites signals in wefax mode

Yaesu FT-857 features and specifications

The page discusses Axial-Mode Helical Antennas, focusing on turning helical antennas over perfect ground and modeling helices in NEC-2 for optimized design. It covers topics such as high-gain performance, broadband, impedance matching, radiation pattern, feedline, balun, near field, far field, and DIY applications.

The aim of the project is test if fractal antennas can work acceptably on HF bands.

G3TPW CobWebb Antenna for the 14, 18, 21, 24 and 28 MHz Bands

About HF Wire Antennas for field day or any day a basic wire antenna article

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

Demonstrates the product line of _LZ Antenna Ltd._, a Bulgarian manufacturer specializing in amateur radio antennas and custom electronic devices. The company focuses on robust, high-quality HF multiband Yagi and vertical antennas, leveraging over 20 years of experience from founder Georgi Georgiev in radio amateur development. Featured models include the LZA 8-4, LZA-10-3, and the LZA-7-3A WRTC 2022, alongside various rotary dipoles like the LZA1 40/30m. Provides specifications for several Yagi antennas, such as the LZA-9-5, LZA-13-7, and LZA-6-3 (a 6-element, 3-band design). The company emphasizes applying "leading edge technology" to high-frequency communication equipment production, with products designed for durability and performance. The LZA-10-5 Yagi offers **12.5 dBi** gain on 10m, while the LZA-13-7 provides **13.2 dBi** on 20m, showcasing competitive gain figures for DXing and contesting.

By Guy, de ON6MU, At VHF, both the 1/4-wavelength monopole and the 5/8-wavelength monopole antennas are widely used.

Olivia MFSK digital communications are becoming popular in amateur radio because Olivia is one of the most robust methods of text keyboarding, that can perform superbly for long distance communications. Olivia frequencies, format and software

IC-718 tech. specifications

The HF ham bands can be mysterious. Some work at night, some during the day. Some seem to be good for long distance contacts while some are better for nearby contacts. Even worse, they change tremendously from hour to hour and day to day. An overview on operating on HF amateur radio bands

Images of VHF UHF antennas

Compact and efficient magnetic loop antenna that cover from 40 to 10 meters project by G8ODE published by RSARS

A vertical portable antenna system by W0SJS that will work on 40, 30, 20, 17 and 15 meters

The page is about the 144 Mhz Dirty Beacon project, a VHF beacon keyer by 9A4QV. It provides technical information, project details, and resources for amateur radio operators interested in beacon keyers. The content is useful for those looking to build or learn about VHF beacon keyers.

Drake Radio Repairs by Jeff WA8SAJ

The Yaesu FT-100 is a miniature mobile transceiver that provides coverage of the 160 to 6 meter bands plus the 144 MHz and 430 MHz bands

The **HFRadioSales.au** resource provides a commercial outlet for amateur and commercial radio operators seeking HF SSB equipment and related services. It focuses on the Australian market, offering new and refurbished transceivers, antennas, tuners, and a wide array of spare parts for brands like Codan, Barrett, and Qmac. The site details its role as a licensed dealer for new Barrett Communications and Codan radio and antenna systems, including specific models such as the Barrett 4050, 2050, and 950, and Codan Envoy and NGT series. This platform supports various applications, including vehicle, 4WD, outback, marine, and base station setups, catering to networks like HF Radio Club, VKS737, and RFDS. It also features commercial-grade antennas from Bushcomm, such as the BBA100C and SWC100, available for fast shipping from their Queensland warehouse. The site includes an FAQ section with general information on mobile HF communications in Australia and timelines for specific transceiver models.

An interesting project about an Arduino-based frequency counter fot the Kenwood TS-520S

Topic regarding a new 1KW HF power amplifier with 2x GI7B

HF Weather Fax lets you receive marine weather radiofascimile transmissions on your iPad, iPhone and iPod Touch. Just connect it to a shortwave radio tune in a weather fax frequency, and watch the images come in.

AA5TB homemade balun article

An easily transportable vertical antenna for 20 meters collapsible to 4 feet

Demonstrates the construction and measurement of a single-turn HF receiving loop antenna, built from common materials like electrical conduit and lamp cord. The resource details the physical dimensions, including a 4-meter circumference, and calculates the theoretical inductance at approximately _6.4 uH_. It outlines a method for determining resonant frequencies across the 4-17 MHz range using a _C Jig_ and a _VR-500 receiver_, coupling the loop with a ferrite ring. The article also discusses the impact of receiver coupling on the loop's Q factor, noting a degradation in sharpness due to the transformer's reflected impedance. Analyzes the observed resonant frequency patterns, highlighting an unexpected rise in the loop's effective inductance at higher frequencies, particularly above 13 MHz. While some increase is attributed to distributed capacitance, the rate of rise suggests further investigation. The experimental setup provides practical insights into the challenges of maintaining high Q in simple receiving loops and offers a comparative reference for other homebrew antenna projects, such as those by _VK2TPM_.

Official Icom comparison chart for IC 756 PRO III, IC-7600, IC-7700 and IC-7800

A triband VHF Yagi antenna for 6 m, 4 m and 2 m with one feed-point by DK7ZB