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Horn Antennas theory and principles

Here you will be able to access all of the information regarding our amateur radio disaster relief communications organization, its divisions and volunteer members

Antennas are influenced by the effect of the ground and by the type of conductors from which they are constructed. Effects of various types of grounds on a 1.825 MHz horizontal 0.5 wave dipole

VHF Broadcast Passband Filter (88 108 MHz) by DF9CY

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.

Mullard Radio Astronomy Observatory

Comment on W5DXP 2011 coil measurement experiment

The Central Arizona DX Association is an ARRL-affiliated club.

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

The Las Cumbres Amateur Radio Club "From the Sierra to the Sea, this is K6FB repeater"

A DX and Contest Minded Amateur Radio Club Serving the California Coast North of the Golden Gate Bridge

K8qik amateur radio club

Yaesu ATAS 120 Autotune Antenna Repair

Moxon is a rectangle shaped directional antenna, originally designed by Les Moxon G6XN. There are couple of advantages of using this antenna. It is small in size, Easy to mast, Balanced to 50 Ohms, Near 1:1 SWR, Excellent Front to Back (F/B) ratio, Large bandwidth

Dxpedition information site has dates, frequencies, operators etc. Planning a searchable data base for logs.

Newsletter of the Silverado Amateur Radio Society Napa California

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

Homebrewing portable antennas for field day operations

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

WA1ION article on beverage and ewe antennas

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

Homebrew Amateur Radio 440Mhz Interdigital Bandpass Filter

A collection of audio amplifier projects by N1HFX

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

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

Indiana's Premier Repeater Group An ARRL affiliated organization

Dx-pedition in Lebanon on July 2004 by I1HJT - I1NVU - IK1QBT - OD5LN pictures and Log on-line it's available on web site. Qsl via I1HJT

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.

Facilitates logging of amateur radio contacts directly within a web browser, enabling seamless operation across various devices including Windows, macOS, Linux, iOS, and Android. This web-based application stores all log data securely in the cloud, providing accessibility from any internet-connected location. It supports importing existing log data via CSV files, with future plans for _ADIF_ file import, and offers a robust QSL card generation feature, producing print-ready PDF files in standard 148mm x 100mm dimensions. The platform integrates with Japanese government databases to automatically populate callsign-related information such as station location and license issue dates, streamlining data entry. It also assists with JCC/JCG searches for accurate QTH logging. The service leverages SSL encryption for all communications and benefits from security oversight by certified information security professionals. Users can register using email/password or existing Facebook/Google accounts, and the beta version is currently available for free. The system has processed over **5,297,881** logs, with **28,369** logs recorded in the past 24 hours.

NRAL at Jodrell Bank are a part of the University of Manchester's Department of Physics and Astronomy. The Laboratories are home to the Lovell Telescope and the MERLIN & VLBI National Facility which is operated by the University on behalf of PPARC.

N1HFX project to improve PL tone encoder providing a more stable frequency

KC5M frequency measurement with yaesu ft-920

Listen to Cleveland Police Dispatch and Metro Housing Authority via the Live Audio Feed Web Player

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

Fall River Amateur Radio Club

The South Mountain Repeater Association (SMRA) is a 501(c)(3) non-profit group of amateur radio operators dedicated to community service and emergency communications within Cumberland County and the surrounding area in Central Pennsylvania.

Understanding Amateur Radio NVIS Antennas and Propagation

The MMMonVHF database, curated by DL8EBW, currently lists 63,455 entries for VHF operators, providing a searchable resource for locating stations active on 144 MHz and higher bands. Operators can register their callsigns to be included, with specific criteria such as participation in _MS_ (Meteor Scatter), _WSJT_ modes, or _EME_ (Earth-Moon-Earth) operations required for inclusion in the `call3.txt` file. This resource facilitates VHF DX expeditions and contest planning by allowing users to identify potential contacts within a geographical area. The database supports various VHF/UHF operating modes, including those focused on weak signal propagation. Statistical data regarding the database entries is also presented, offering insights into the distribution of registered VHF activity.

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.

List of APRS server worlwide mantained by ae5pl

NHRC-2 Based Repeater Controller A perfect controller for a simple repeater or link, or portable/solar powered system.

A Tape Measure Beam Antenna for Radio Direction Finding based on WB2HOL design.

Calculate how to set call signs

A non-profit organization seeking to preserve the history of the development of wireless communication by encouraging the acquisition, restoration, preservation and exhibition of antique wireless and radio apparatus

A 7 dB directional gain is reported for this portable VHF Yagi antenna design, which utilizes cut metal tape measure sections for its elements. The resource details the construction process for a 2-meter band antenna, emphasizing its ease of build and portability. It specifically mentions the design's suitability for radio direction finding (RDF), fox hunting, and communication with satellites and the International Space Station (ISS), highlighting its practical applications for amateur radio operators. The construction cost is estimated at under $20, with potential for even lower expense if salvaged materials like old tape measures and PVC pipes are used. The article references _Joe Leggio's_ (WB2HOL) original design, noting specific alterations made by the author. It also compares this design to other DIY Yagi antennas, including _FN64's_ 2-meter band and _manuka's_ 70-cm band tape measure Yagis, underscoring its unique combination of simplicity, portability, and effective performance with a 1:1 SWR achievable on the 2-meter band.

Anaheim amateur radio association - k6syu

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

An interesting article on grounding and receiver noise