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Excellent guide to build your own G5RV antenna by Lombry

Some tens of very special audio files recorded during amateur radio activities like aurora traffic, meteor scatter, communications with ISS crew and the sound of various transmission modes that you can hear on HF and VHF bands

Theory, Modeling, and Practical Applications By W5JCK, presentation in PDF File. This presentation focuses on Near-Vertical Incidence Skywave (NVIS) antennas, which are crucial for short-range radio communications, particularly in military and emergency contexts. It explores NVIS theory, antenna models, and installation criteria while debunking common myths about reflectors. Key topics include usable frequency bands, optimal installation heights, and the impact of soil quality on performance. The presentation outlines the best bands for daytime and nighttime use, emphasizing the importance of understanding propagation characteristics to enhance communication effectiveness within 200 to 300 miles.

Excel sheet containing technical comparisons of commercial HF portable antennas compiled by ON4SKY. Includes pictures, manufacturer, db gain, band coverage, F/B ratio, price, weight and dimensions.

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.

Modify an Analogue Sky TV Offset Fed Dish for AO-40 S-Band

Near Vertical Incidence Skywave (NVIS) and the 40 meter Novice Sub-band.

Deploying robust antenna infrastructure for both fixed and portable operations often requires specialized support structures capable of withstanding environmental stresses while providing optimal radiating element placement. SMC offers a range of solutions, including pneumatic masts and push-up masts, designed to facilitate rapid deployment and reliable long-term support for various antenna types. Their product line encompasses antenna mounts, poles, and complete antenna systems, addressing the critical need for stable and efficient RF communication. The company's offerings extend to HF antennas, including dipoles and _NVIS_ (Near Vertical Incidence Skywave) antennas, which are crucial for short-range regional communications on bands like 80m and 40m. These systems are engineered for durability and performance, ensuring signal integrity across diverse operating conditions. With over **65 years** of experience, SMC has established itself as a global manufacturer in this niche. Their product portfolio also includes antenna support towers, catering to more permanent installations requiring significant height and load capacity for multiple arrays.

A Wire resonant loop antenna for 160 meters band article by N4KC

This is a computer program for Amateur Radio transmission and reception using a computer and radio transceiver The program equips your computer with a one sentence at a time chat-mode for operation on the HF bands. You use it in the same way as you would Skype or cell-phone TXTing. This facilitates rapid-fire QSOs and especially makes nets easier by ZL2AFP

Comparing many antennas for 50 MHz band

Near Vertical Incidence Skywave propagation is a form of radio wave propagation used on the MF and HF bands to provide radio communications and broadcasting coverage over short distances, especially where the terrain contains obstacles.

Making EME contacts on six meter band. An US Experience using a pair of 8 yagi arrays for the 50 Mhz.

This website explains signal variations on a local radio net by tracking the foF2, a measure of ionosphere's ability to reflect radio waves. The website shows daily foF2 variations and how it affects Near Vertical Incidence Skywave (NVIS) propagation for local nets. It also considers D-layer absorption affecting lower bands and F2 MUF distance for long-distance communication. Additionally, the website tracks foEs for E-layer propagation and an EPI index for predicting Es chances.

This is a theoretical look at propagation on 630-Meters and 2200-Meters using ray tracing software. It expands on the brief discussion in the ARRL Handbooks. The Earth's magnetic field affects 630-Meter and 2200-Meter band propagation. Lower ionization reduces absorption, aiding low-frequency propagation. Differences exist between bands, limited daytime sky-wave propagation. Sunrise/sunset show promise, yet mechanisms are unclear. Ducting possible at night in specific conditions. Negative ions enhance propagation. Inefficient antennas and high man-made noise are anticipated. Groundwave propagation is significant on 2200-Meters.