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A study on 20m antennas by Kenny Silverman, K2KW

A review of the Superantennas MP-1 portable HF antenna

This article deal with various means to covertly operate radio systems while going unobserved.

Horn Antennas theory and principles

A considerably shortened Magnetic Loop antenna with performance of a single conductor text book magnetic loop.

A review of all possible receiving antennas for top band 160 meters

N5KGL interesting article on portable antennas. Greg report his experience on using several types of portable antennas.

Ultra portable and lightweight folding beam antennas based on G3TXQ design

How manage and quantify ground loss in vertically-polarized antennas by VE3VN

How to build Fan-Dipoles by DK7ZB. Experiences with various band combinations. Not all combinations are working properly. If the frequencies are to close together the impedances will lead to a very bad SWR. This happens with the bands 10-12-15m or 15-17-20m.

WA1ION article on beverage and ewe antennas

In this article you can find solutions to the problem of keeping your ham radio antennas hidden from the CCR Police

HF VHF UHF antenna ideas to be used for field days. All antennas are quick to set up and take down and offer proven performance and flexibility. Presentation offered by Mahoning Country ARES

W3HH wide-band wire antenna Article in French. The W3HH antenna, also known as the Terminated Folded Dipole (T2FD), is a compact, broadband antenna for amateur radio. It operates at an angle of 20 to 40 degrees and covers frequencies from 3 to 30 MHz. The antenna features a total length of one-third of the wavelength at its lowest frequency and is fed using a 1:4 BALUN transformer for impedance matching. A termination resistor around 390 Ω optimizes performance, making it suitable for various amateur radio applications while being easy to construct and install.

Essentially, a choke balun is designed to 'divorce' your antenna from the feed line. if your feed line is coaxial cable then you don't want it to be part of your antenna. you want to be able to deliver all your power to the radiator itself, i.e. 'the antenna'. a choke balun does this admirably

Understanding Amateur Radio NVIS Antennas and Propagation

SPIDERBEAM.US is the exclusive distributor of Spiderbeam antennas, and online shop for USA & CANADA

1:49 UNUN using two stacked FT240-43 cores for end fed halfwave antenna. To match the end fed half wave antenna to the coaxial feeder, it is necessary to have a matching network or transmission line transformer.

Antennas, Transmission Lines, Tuners - Myths, Mysteries and Qualifiers By Don Wilhelm W3FPR

A page describing how to home made a custom 9:1 balun for a common portable wire antenna. The author suggest to use 4C65 or FT140-61 toroids instead of the common Amidon T200-2

Two different ways to create autotransformer for end fed half wave wire antennas, by using ferrite or air core.

A delta loop antenna for 20 meters band designed with MMana with a tuning system made in a classic stub configuration

Australian manufacturer of HF Communications Antenna Systems for Military, Comercial, Mining & Amateur Radio

SPX Communication Technologies, operating under the TCI International brand, presents a range of radio frequency (RF) solutions primarily for government, defense, and commercial sectors. The offerings include advanced systems for spectrum monitoring, communications intelligence (COMINT), and high-frequency (HF) and medium-frequency (MF) broadcasting and communication antenna systems. Specific product lines encompass _Blackbird_ COMINT systems, _Scout_ spectrum monitoring receivers, and various antenna arrays designed for robust performance in challenging RF environments. The resource details the capabilities of these systems, such as wideband signal detection, direction finding (DF), and signal analysis, crucial for intelligence gathering and regulatory compliance. It also highlights the engineering behind their antenna designs, which are optimized for specific frequency ranges and operational requirements, including high-power broadcast applications and secure military communications. The information presented emphasizes the integration of hardware and software for comprehensive RF situational awareness. The company's focus on empowering partners to "Command the Spectrum" underscores its commitment to delivering critical tools for signal interception, analysis, and management across diverse operational landscapes.

Pictures, design plan and description of a 5 element yagi antenna for the 4 meters band by 9A7PJT

The problem originates by improper TXOUT-to-RF timing (RF transmission exists still after a TX-EN prohibition), combined by too long decay of their CW pulses.

An overview of the basics of the horn antenna used in RF microwave applications.

SJ2W Contest Station, antenna for the 160 meter is a 39m vertical. This 160m antenna consist of 29m of WIBE tower sections with an insulated base and 10m top tube.

160 to 40 meters inverted L antennas projects

Summary, tutorial about the basics of what is a waveguide and the basic waveguide theory.

Antenna gain and directivity explained in this article at radio electronics antenna pages

A simple dipole for 40m band feeded with 450-Ohm openwire feedline includes MMANA Gal files to download

A page dedicated to servicing and building a 10 meter band moxon Antenna

Article on Phase-cancellation of noise on 2m band

The collinear antenna, or Marconi-Franklin antenna, is an omnidirectional, high-gain antenna composed of in-phase half-wave dipoles aligned vertically. By using quarter-wave transmission line segments, it maximizes gain at a low horizon angle, outperforming a half-wave dipole. Adding segments increases gain but narrows bandwidth. A popular DIY version, the CoCo antenna, uses half-wave coaxial cable segments connected by non-radiating transmission lines. Built with stable velocity factor cables, a matching quarter-wave sleeve balun, and ferrite rings for attenuation, the antenna achieves performance comparable to commercial models.

Comparison of some popular 432 MHz EME antennas by DF9CY

Which is better a 20m antenna for an island DXpedition: Yagi at 25', or a vertical or two on the beach?

IZ5CML, Enrico Giannerini, obtained his amateur radio license in 1998, achieving DXCC contacts with all entities over 18 years of activity. His station, located in Empoli, Tuscany, Italy, focuses on HF and 50 MHz operations, primarily using SSB, CW, and some RTTY. He emphasizes direct radio communication, preferring "human modes" over digital modes like FT8/4, which he views as detaching the operator from the signal. Enrico's operating interests include DXing, IOTA activations, and major HF contests, where he has participated both individually and with teams like IQ5LV and IO5O. Notable activations include Sao Miguel and Flores (CU8, EU-089) in the Azores in 2005, and Antiparos and Paros (EU-067) in Greece in 2006 and 2014. He also contributes to the Hamradioweb forum, promoting good operating practices and publishing the monthly "Dxschedule" for upcoming DX and contest activities. The website includes a blog with articles on DX, ionospheric propagation, and antennas, reflecting his long-standing passion for radio, sparked by the 1980s film "La Tenda Rossa" and years as an SWL.

Isotron antennas are antennas of reduced size, without tuning. On 40 and 80m band, it is made of two plates into v whose angles are connected by a coil. In this article the description of a home made realization for the 40m band.

How to improve your transmitting antennas for very low solar activity periods, vertically polarized 160 meter antennas, horizontally polarized 80 to 10 meter antennas, single or stacked yagis, multi-tower stations

Antennas manufacturer based in Germany produce portable and wire HF VHF antennas

Antenna Authority Inc. offers a wide assortment of directional, wideband antennas and other equipment specifically engineered for radio direction finding (DFing) and geolocation applications. Their product line includes _log periodic_, _cavity-backed spirals_, and _Yagi_ antennas, alongside covert antenna solutions for various operational requirements. The company emphasizes its expertise in designing and manufacturing specialized antennas for both overt and covert operations. Beyond standard offerings, Antenna Authority Inc. provides custom design services to meet specific client needs, focusing on tailored RF directional products. Their capabilities extend to developing antennas for vehicles and optimizing their operational performance in diverse scenarios. The firm is located at 3381 W. County Line Road, Douglasville, Ga. 30135-1145. Ferrel Bentley is associated with Antenna Authority Inc., which has been operating since at least 2005, as indicated by the copyright notice.

Slim Jim Antennas are great for apartments and hotels. VHF UHF Antennas

Main High Frequency Antennas from the 2009 LARC FARL Field Day, Ford Amateur Radio League. A document comparing antenna performances and flexibility among a G5RV an Carolina Windom and a Cushcraft R7 vertical antenna.

Distributed Antenna Systems technology used for gaining better coverage and using a lower power.

A dual band dipole antenna for 40 and 80 meters band. Total lenght of 26 meters, foreseen two coils at aprox 11 meters distance from center feed.

Smart antennas or the adaptive antenna array and smart antenna technology used with SDR, cognitive radio, MIMO, and other new technologies.

Extending The Bandwidth of 80 Meter Dipoles

FA-Kleinanzeigen is a dedicated platform for amateur radio enthusiasts in Germany to buy and sell equipment. The site features a wide range of classified ads, including HF and VHF radios, antennas, and accessories. Users can post their listings for free, making it an accessible resource for both seasoned operators and newcomers looking for second-hand gear. The platform categorizes listings into various sections, such as QRP technology, military radios, and even antique equipment, catering to diverse interests within the ham radio community. In addition to equipment sales, FA-Kleinanzeigen also allows users to search for specific items, making it easier to find rare or specialized gear. The site emphasizes user engagement, encouraging individuals to create accounts for posting ads and interacting with other members. With a focus on the German market, it serves as a valuable resource for local hams seeking to expand their stations or offload surplus equipment. Whether you're looking for a new transceiver or just browsing for interesting finds, FA-Kleinanzeigen is a go-to destination for amateur radio classifieds.

Relevance of a proper ground systems on short HF vertical antennas, with an analysis on a vertical antenna for 160 meter band