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The page provides guidance on building a mobile antenna for HF bands using a cheap CB-mobile whip antenna base. It discusses the importance of high efficiency antenna systems with a slim profile for low wind resistance, along with physical constraints and design considerations. The author shares instructions, tips on mounting the antenna, grounding, and band switching. The page includes a graphic illustrating the antenna's principle of operation and a table with reference lengths for different bands.

The Pfeiffer Maltese Quad Antenna System presents a unique approach to traditional quad antennas by utilizing a linear loading technique. This method effectively reduces the overall size of the antenna while maintaining its performance capabilities. Designed by Andrew Pfeiffer, the antenna's configuration resembles a Maltese cross, which not only enhances its structural integrity but also allows it to withstand challenging environmental conditions. This system is adaptable, offering various configurations from a 4-spreader Maltese Quad to a 16-spreader Maltese Quadruple-Cross, making it suitable for operators looking to optimize their setup without sacrificing efficiency. This antenna system is particularly versatile, covering multiple bands including 40, 20, 17, 12, and 10 meters. The design focuses on minimizing the physical footprint while ensuring effective signal transmission and reception. Amateur radio operators can benefit from the detailed plans available in the accompanying PDF, which outlines the construction process and specifications. Whether you're a seasoned DXer or a newcomer to the hobby, the Pfeiffer Maltese Quad Antenna System offers a practical solution for enhancing your station's capabilities.

A new, revolutionary design allows the construction of small HF antennas, which provide the same efficiency as large antennas. This antenna can be built for all HF bands, from 10 to 80 m.

This Vertical antenna design by David Reid for lower bands focuses on achieving effective DX communication by optimizing the antenna low-angle radiation for long-distance contacts. The design incorporates techniques like linear loading and capacity hats to reduce the antenna's height while maintaining performance, especially on 40m and 80m bands. Building a solid ground plane and using quality materials ensure efficiency and durability. Although vertical antennas can be complex to build, this project simplifies the process, making it accessible for ham operators seeking strong, reliable signals.

The resource provides detailed information about a five-band indoor magnetic loop antenna designed for amateur radio operators. This antenna is capable of operating on the 20, 17, 15, 12, and 10 meter bands, making it a versatile choice for various HF communications. Constructed from a single 3-meter length of 22 mm copper tube, the design emphasizes compactness and efficiency, which is particularly beneficial for operators with limited space. The page includes insights into the construction process, tuning, and operational tips, catering to both novice and experienced users. In addition to the technical specifications, the resource also discusses the advantages of using a magnetic loop antenna indoors, such as reduced interference and improved performance in urban environments. It serves as a practical guide for those interested in building their own antenna, offering a straightforward approach to antenna design and construction. Overall, this resource is a valuable addition to the toolkit of amateur radio enthusiasts looking to enhance their station with an effective indoor antenna solution.

Effective HF Mobile Antennas Keith WB2VUO, explains difficulties on gaining antennas efficiency on lower bands with mobile antennas.

A large jpeg DX World map that include ITU Zones, grid squares and prefixes. This high-resolution DX World Map is an essential tool for amateur radio operators. It clearly displays ITU zones, CQ zones, grid squares (Maidenhead Locator), and DXCC prefixes, helping you to plan QSOs, track propagation paths, and participate in global contests. Whether you are a seasoned DXer or a beginner, this map provides a clear, detailed view of the radio world, improving your station's efficiency and geographic awareness. Available in JPEG format, it's perfect for display

MMVARI is a multi-Mode SoundCard Ham (Amateur) Radio program for receiving and transmitting the RTTY-PSK-FSK-MFSK modes. The program was written to experiment with the efficiency of transmitting Japanese and East Asian languages (HL/BV/BY) using the VARICODE

Ham Radio Antenna Tuners--Full Legal Power--Patented Circuit--Outstanding Efficiency and Power Capability

Mobile antennas, loading coil current, and loaded antennas. efficiency and electrical rules. Loading inductors used in mobile HF antennas.

A High Efficiency Extended Length Mobile Antenna The antenna itself is 3.42 meters or 11 feet 2 inches long from the top of the mounting spring to the tip.

The Crossed Field Antenna (CFA) is one of the applications of Correction of Maxwell's Equations which was used over 150 years ago which was proved these days that the Magnetic Field Source is only the Displacement Current not the Conduction Current . These Corrections was made by an Egyptian Doctor Engineer Fathi Kabbary , who reached the New Correct Theory which shows that the height and efficiency of the antenna doesn't depend on the wavelength

This group has been created to promote discussion relating to the EH Antenna. There should be many with experience with the EH Antenna, so don't be shy about asking questions on construction and efficiency.

Very compact and high efficiency antenna ,very low radiation angle even at low height.

Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency

This calculator is designed to give the efficiency loss of a given antenna, based on the input of VSWR (voltage standing wave ratio) and other subsequent factors

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

Although a magnetic loop antenna(aka small loop antenna) is very compact, its efficiency is close to a half-wavelength dipole if carefully built.

RF and Microwave Power Amplifier and Transmitter Technologies, amplifierlinearity, efficiency and available RF power devices.

Solartech Power Inc. manufactures, distributes and sells high efficiency solar panels and wind power turbines.

An Experimental, High-efficiency, Graphic-Tunable Magnetic Loop antenna and loop controller in a 52 pages PDF presentation with drawings and pictures

Guide to ground mounting antennas, notes on efficiency, elevated installations, metal towers and masts, other mounting schemas, moble homes and rv, lightning protections, artiche by Bencher

Two Delta-Loops in phase. The purpose of this article is to propose an antenna with a high gain, a high efficiency and a very low price that is easy to build for any frequency.

Various configurations of the Z Match Tuner are tested for power efficiency over a wide range of antenna load conditions

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.

Octagonal magentic loop antennas that work from 20 to 10 meters with pictures and efficiency reports by G1KEA

Iambic Keying, Debunking the Myth by Marshall G. Emm, N1FN. A keying system controls transmitter activation, ranging from basic switches to electronic keyers that generate Morse code based on paddle input. Iambic keyers, introduced in the late 1950s, respond to simultaneous paddle closures with alternating dots and dashes. Despite touted efficiency, actual benefits are modest, offering about a 5% improvement in keystrokes, diminishing at higher speeds. Iambic keying's practical value is limited and may restrict sending speeds.

This calculator estimates the efficiency of a T match tuner using a simple loss model.

If you want to design vertical antennas you can find all theory and formulas used to model a vertical aerial calculating capacitance, reactance, building the inductor and calculating resistances. Includes an excel spreadsheet to calculate efficiency.

It is our purpose to further the exchange of information and cooperation between members, to promote radio knowledge, fraternalism and individual operating efficiency

The Radio Operators Association of Dallas (ROADS) Club exist to promote interest in amateur radio communication and experimentation, fostering of education in electronic communications as it applies to amateur radio, development of individual efficiency, cooperation among members. and furtherance of the public welfare.

The Bristol Amateur Radio Club's purpose is to: Facilitate the exchange of information and general cooperation between members to promote amateur radio knowledge, fraternalism and individual operating efficiency

In this article, author examine stresses placed on common-mode chokes (aka baluns) as hams use/abuse them, examine the efficiency of simple dipole multi- band antennas and their feed systems. Stressing a Balun.

Article appeared on 10/05 issue of QEX about the impact of load SWR on the efficiency of Power Amplifiers, PDF File by K9LA

Article on antenna feed impedance and the importance of matching RF andtennas to feeders, including notes on Radiation resistance, loss resistance, and efficiency are also detailed.

A classic document originally presented in Proceedings of the Institute of Radio Engineers in 1937 and is, still today, the standard referenced by the FCC, text books and many amateur radio publications.

Effect of radials on the efficiency of antennas.

Ultra High Efficiency Alternative Energy System Controllers

This article is about two excellent small helical antennas for the two meters band. With performance close to that of full sized antennas, these small helical antennas are low in profile but high in efficiency.

An article by CT1BOH about recording amateur radio contests. Recording contests is a great tool to detect problems and improve operating efficiency

This is a Solid State Amplifier Project. It uses 4 MRF150 MosFet Power Transistors. The Power Supply Voltage is 50 VDC at 21.5 Amp. The max power available is 1,075 Watts. The Efficiency is about 65% +/- and runs Class AB Solid State.

Basic magnetic loop antenna examples and loop aerials theory explained. This article inclued some interesting tricks on building magnetic loop antennas and an usefull excell sheet to help compute magneti loop antennas calculating power efficiency from 10 to 40 meters band

Hytera, a leading designer and manufacturer of professional mobile radio communication equipment, offers complete and customized communication solutions to government, public security, utility, transportation, enterprise & business for higher organizational efficiency.

High quality RF coax cables designed for ham radio use featuring high efficiency screening attenuation and transfer impedance.

The Terminated End Fed Vee Antenna (TEFV) is a travelling wave antenna with constant current distribution. Unlike traditional resonant antennas, TEFV operates without standing waves, using a terminating resistor for broadband efficiency. With a combination of vertical and horizontal polarization, it offers wide bandwidth from 1.8 MHz to 30 MHz, eliminating the need for a tuner. Key components include a 9:1 unun transformer and a 500-ohm terminating resistor. Grounding and counterpoise enhance performance, and it can handle power losses of up to 30%. TEFV provides an effective, versatile antenna solution for amateur radio and broadcast applications.

F5NPV introduces a variant of the W8JK antenna design, employing the MOXON principle. With extended monopoles, it outperforms the Open-Folded W8JK, yielding a 1dbd gain improvement, enhanced performance on 30m and 10m bands, bi-directionality, and lower side attenuation. The design's focus on higher radiation impedance results in increased antenna efficiency and reduced losses. Despite these improvements, the bill of materials remains unchanged.

Not a project yet, but very theoretical thoughts about very practical amplifiers!

You can bend the wires in a half-wave dipole so that it takes up less space, with minimal loss of efficiency.It is advisable to get the ends of the antenna as high as possible, especially if children and animals are kept in the area around the antenna, as there are very high tensions on the ends of the antenna during transmission! In Norwegian

In pursuit of enhanced station efficiency, the author describes crafting an Arduino-based smart antenna switcher for an SO2R setup. Faced with manual antenna switching challenges during contests, the project utilizes a Logos Electromechanical 4x4 Driver Shield and a Power Screw shield for seamless functionality. Despite its raw appearance, the automatic switcher proves indispensable in contest scenarios, prompting considerations for future improvements and standardization of station control protocols.

In this post by N6CTA, discover the conversion of the Yaesu ATAS-120A screwdriver antenna for portable use. The author details the creation of two sets of radials, 16 and 32 in 16ft lengths, aiming to optimize the efficiency of ground-mounted antennas. Additionally, insights are shared on attaching male quick disconnect blade tabs, with potential plans for a radial plate kit.