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This version of the broadband hexbeam is based on the work of Hunt G3TXQ, HB9MCZ, and Shoemaker K4KIO. EZNEC model is based on a wider element spacing than the version published in QST by K4KIO

VHF Broadcast Passband Filter (88 108 MHz) by DF9CY

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

A interesting guide to help get started with HF published at Essex Ham

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

The RSGB Band Plan is normally published annually in the February edition of RadCom and additionally reviewed mid-year. It is derived from the IARU Region 1 Band Plan taking into account any proposed national variations or special amendments, which are considered necessary by the relevant spectrum manager.

A simple, cheap and easy to build 26 feet long vertical antenna that works DX on 20 - 10 meters including WARC Bands, it is designed for portability for field days, camping, or permanent installation, cost, and to achieve at least 1/2 wavelength on the WARC bands.

The construction principles for open-sleeve elements in antennas

5 Elements 12,5 Ohm Yagi with a 6m Boom

An easy to build and extremely high performance antenna, works perfectly on all HF bands 3.5-28 MHz with some compromises, it is basically an half wave dipole for 40-80 meters, an LC circuit or trap 40 meters allows you to use a single radiating element.

Homebrew Amateur Radio 440Mhz Interdigital Bandpass Filter

Freeband modification for the Yaesu FT-100

Wideband receiving phased arrays with small electric or magnetic active wideband elements are discussed in details. Practical results and examples are given.

Performance data of the KIO Hexagonal Beam antenna

Encouragement for Little Pistols, article originally written for and published in SKIP the monthly newsletter of the Fresno Amateur Radio Club

Adding a full power output 12 meter band capability to the Yaesu FL-2100 despite of 10 meter.

These are QRP rated 3 Pole Butterworth filters based on a design by K4VX, feature simplicity, almost no insertion loss, and reasonable rejection on the other ham bands.

An interesting presetnation full of usefull tricks to correctly design and build 23 cm Yagi using simple tools. The basic design of the antenna presented in this document is taken from the original DL6WU Yagi Design published in 1982

160 to 40 meters inverted L antennas projects

Add bands to your Hustler xBTV Series Vertical

An home made doblet antenna made with two Slinkys that are aproximately five meters in length connected with a twin-feed connected to a balanced ATU

Homemade LC Bandpass Filters for 20M, 30M, 40M In multi-station environments like special events, field day, portable operating, is very important to protect receivers from excessively strong signals. Bandpass filters help to protect your transceivers.

Building an omnidirectionnal antenna for the 23 cm band

A monoband delta loop antenna for the 7 MHz. This vertically polarized DX Antenna is a full wavelength sngle side antenna and has a total length of 42.3 meters (137,1 inch) Can be easily setup with a flag pole or fishing pole as center top mast. For optimal performance lower side should be at 2 meter above the ground. This antenna offers a low radiation angle and 1 DB Gain.

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.

On March 27, 2017, the FCC adopted final rules for the USA 630-meter band, detailed in Report and Order FCC 17-33, which required PLC coordination with the Utilities Telecom Council before amateur operations could commence. This resource documents the WD2XSH experimental group's activities, including authorized stations, band plans, and frequency assignments within the 465-515 KHz range, with many stations operating between 495-499 KHz and 501-510 KHz. The site also highlights the WRC-12 decision on February 14, 2012, which granted a new **7-kilohertz-wide** secondary allocation between _472-479 kHz_ for the Amateur Radio Service worldwide. The group's efforts included operating with a maximum ERP of **20 Watts** across 45 stations in the continental USA, Alaska, and Hawaii, using emission modes such as CW, PSK-31, FSK-31, and MSK-31. The site provides links to download FCC 17-33 in PDF and DOCx formats, and offers a station location map, a list of stations by callsign and frequency, and an archive of news updates. Reception reports for any 600-meter station are encouraged to help the amateur radio community understand propagation and repeatability on this challenging band.

Radioclub KAPA,OM7M Partizanske Slovack republic

A dipole can be broadbanded by a number of techniques including by matching with resonant sections of transmission feed lines.

Extending The Bandwidth of 80 Meter Dipoles

VK1OD informations on BPL

The 2200-meter band (135.7-137.8 kHz) presents unique challenges for amateur radio operators due to its narrow 2.1 kHz bandwidth, low signal levels, and high noise. W1TAG explores various transmission modes suited for this demanding environment, highlighting that traditional voice modes like SSB and AM are impractical. Plain old CW serves as the baseline, demonstrating effectiveness across different modes, though signal-to-noise ratio (SNR) significantly limits practical speeds. The article notes that reducing CW speed below 5 WPM can improve copy, especially with computer-aided spectrum analysis software capable of decoding signals too weak for human ear reception. QRSS, or "CW sent slowly enough that speeds are best expressed in seconds per dot," is a key mode for LF work, with examples ranging from 3 seconds/dot to extreme 240 seconds/dot transmissions. _Argo_ by I2PHD is mentioned as a simple program for QRSS, enabling reception of signals like BRO, a Part 15 beacon, at a distance of **1100 miles**. Other modes discussed include Dual Frequency CW (DFCW), which uses frequency shifts to distinguish dots and dashes, and Binary Phase Shift Keying (BPSK), a phase modulation technique employing 0 to 180-degree phase flips. WOLF (Weak-signal Operation on Low Frequency), a specialized BPSK form by KK7KA, encodes 15-character messages into 960-bit packages, taking 96 seconds to transmit, and has demonstrated successful reception over **672 seconds** for a message from a 1-watt beacon. Further modes include PSK, FSK variations like JASON and MSK, and graphical modes such as Hellschreiber and Chirped Hell. The article concludes with a practical chart comparing the time required to send a simple message like "WD2XES FN42CH " across these diverse LF modes, offering valuable insights for operators planning contacts on the low bands.

A technical explanation of what is a mesh node in HSMM-Mesh HamNet, with explaination of specific roles of each network interface

Wikipedia page on Notch filter, a narrow stopband - high Q factor filter

A trapped multi band end-fed-half-wave antenna for 40/30/20/17/15m.

A multiband J-Pole antenna project that cover 144,220 and 430 MHz. The articles includes several pictures of this multi-band antenna, including handmade schematics and diagrams, project is mainly in Italian

An inverted V Dipole antenna for HF bands, working on 10 20 40 and 80 meters band. PDF Presentation

Amateur radio repeaters extend communication range for mobile and remote stations by retransmitting signals on a different frequency, often for emergency communications. The resource details various repeater bands, noting that 2 meters and 70 cm are primary for activity, with 10-meter repeaters offering potential national and overseas coverage. It specifies **18 channels** on 6 meters and **31 channels** on 2 meters, along with a new 70 cm offset of _7 MHz_ adopted in 2015. The content explains how repeaters can be linked via dedicated transmitters/receivers, landlines, or Internet VoIP systems like _IRLP_ and Echolink, enabling global connections. It also describes simplex gateways for multi-band operation and the use of CTCSS subaudible tones for access control and interference mitigation. The document highlights specialized repeaters for modes beyond voice, such as SSTV and ATV, particularly on 70cm and higher bands. Operational guidelines for efficient and courteous repeater use are referenced, along with links to Australian repeater listings and band plans.

A summary of common calling frequency for each digital mode on that band.

Adapted from a similar project by NA4IT. Made with one quarter wave 2 meter radiating element pointing upward and it is surrounded by four 70 cm elements.

An introduction top operating on 160 meters band, article appeared on November 2006 issue of CQ, PDF file by K9LA

About antenna or aerial resonance and bandwidth and the impact of RF antenna resonance and bandwidth on radio communications systems.

This is a 30-watt sea level beacon intended for the coastal path between Northern and Southern California

In this article the author shows the receiving loop antenna for 160 meters band installed at his QTH. Diagram and movie available. Article in in Turkish but can be translated in english

A travel, or a fixed vertical coax antenna originally designed by PA0FBK. This antenna is very easy to make from a piece of 50 ohm or 75 ohm coaxial cable, and can be either smooth, roll-up version, or rigid cable

RF amplifier products from NP Technologies, Inc. encompass a wide array of specialized designs, including highly linear Class A broadband amplifiers, crucial for maintaining signal integrity across various frequencies. Their portfolio also features cell band amplifiers, specifically engineered for cellular communication infrastructure, and pulse amplifiers, which are vital in applications requiring high-power, short-duration signal bursts. The company's manufacturing capabilities extend to AM and FM broadcast amplifiers, supporting radio transmission systems, and military VHF amplifiers, designed to meet rigorous defense specifications for robust and reliable communications. NP Technologies, Inc. emphasizes comprehensive development, design, manufacturing, and testing processes for all its RF amplifier offerings. This integrated approach ensures that each product, from initial concept to final deployment, adheres to stringent performance and reliability standards. The company's expertise in these areas allows for the creation of custom solutions tailored to specific client requirements, addressing complex RF challenges in diverse operational environments. Their product range demonstrates a commitment to serving multiple sectors, including commercial broadcasting, telecommunications, and defense. The focus on specialized amplifier types underscores their technical depth in RF engineering.

The Homebase-10 is a wire halo antenna for 10m built with DIY store parts, effective despite its small size. Includes a dual-band version for 10m and 6m with gain around 0 to -2dBd, near omnidirectional pattern, and horizontal polarization. Overview based on a 2008 Practical Wireless article.

Summit Prowler 6 is a pocket-sized SSB/CW transceiver for 80, 40, 30 and 20m

A multi band antenna for HF band capable to operate from 10 to 80 meters band depending on wire lenght loaded with a small inductance neat the feed end.

IARU Regional bandplans

The equipment shown on this page comprises a basic G3WDG transmit and receive system with the addition of a 1W Qualcomm amplifier.