Search results

Complete introduction to amateur radio, excellent resource for beginners.

The Bruce array is a simple, often-forgotten wire antenna array that is advantageous for 80 and 160 meters, where typical gain antennas are very large. This bi-directional broadside vertical array is only 1\4 lambda high and does not require a ground system. It offers substantially greater SWR bandwidth than the half-square or bobtail curtain. A 4-element Bruce array used by N6LF showed a gain of about 4.6 dB compared to a 1\4 lambda vertical with 8 elevated radials, with a 2:1 SWR bandwidth greater than 400 kHz. The antenna is simple and its dimensions are flexible.

Presents a catalog of **QRP** transceivers, antenna tuners, and related accessories for amateur radio operators. The product line includes the ZM-2 antenna tuner, designed for efficient impedance matching across HF bands, and the NW-series QRP transceivers, offering low-power CW operation. Additionally, the site details various ladder line insulators and specialized connectors, emphasizing robust construction for field deployment and home station use. Each product listing provides specifications, operational parameters, and pricing information. Compares the features of different **QRP transceiver** models, such as the NW-40 and NW-20, highlighting their respective band coverage and power output capabilities. The ZM-2 tuner's performance is detailed with typical SWR reduction figures for various antenna types, demonstrating its utility for portable and fixed stations. Customer testimonials and product images illustrate the practical application and build quality of EMTECH's offerings, providing insights into their durability and ease of integration into existing amateur radio setups.

A simple dual band VHF UHF jpole antenna Projects by Dale Kubichek

This antenna is easy to build and suitable for broadband work, satellite work and terrestrial work.

A bazooka antenna project for the 7 Mhz, includes dimension for to homebrew your own bazooka for HF bands

Attic Fan dipole antenna that allow to operate QRP from 40 metres to 10 metres, specifically 40, 20, 17, 15 & 10 meter band

The N2CKH travel special 300 Ohm ladder line convertable antenna

The SoftRock-40 is a small, low-cost, good-performing "software defined radio" receiver that plugs into a computer USB port and delivers I-Q audio signals to the computer's sound card. It was designed by Tony Parks, KB9YIG and Bill Tracey, KD5TFD as an "SDR sampler project" for hams everywhere to easily try out software defined radio.

This circuit is unique in that it uses a power mosfet as a final rather than a conventional bipolar transistor.

Manual for R7, 10 12 15 16 20 30 40 meters band antenna

A homebrew project of a quadruple helix antenna system based on G3RUH 16 turn helix antenna for 2.4 GHz.

Homebrew a vertical dipole for 28 Mhz by N2UHC

Catalogs a diverse array of Software Defined Radio (SDR) projects and realizations, systematically classified by their sampling methodologies and underlying hardware architectures. The resource delineates projects into categories such as those utilizing soundcard sampling of traditional transceiver audio outputs (Type Ia), mono soundcard sampling of intermediate frequencies (Type R1x-x-xx), stereo soundcard sampling of I/Q IFs (Type Q1x-x-xx), dedicated stereo audio ADC sampling of I/Q IFs (Type Q2x-x-xx), direct antenna RF signal sampling with off-the-shelf acquisition boards (Type R3x-x-xx), dedicated RF ADC sampling of analog IFs (Type R2x-x-xx), dedicated RF ADC sampling of direct antenna RF signals with ASIC-based processing (Type R4x-A-xx), FPGA-based processing (Type R4x-F-xx), and specialized IF chipsets combining ADC and DDC functions (Type Dxx-S-xx). Each entry provides a brief description, often including pricing, availability of source code, and specific hardware components like ADCs, DACs, DDS, and FPGAs. The compilation presents various practical applications, from PSK31 and Packet radio implementations to adaptations of the DRM standard for amateur radio bandwidths, such as Hamdream and WinDRM. It features specific hardware designs like the SoftRock-40 for the 40-meter band, the Firefly SDR for 30m and 40m, and more complex systems like the Quicksilver QS1R, which employs a 16-bit 130 Msamples/s ADC and an Altera Cyclone III FPGA. The resource also lists sample processing software, RF front-end designs, and academic/commercial SDR initiatives, offering insights into different approaches for I/Q conversion and digital signal processing in SDR systems.

This multiband wire antenna it is an off centre fed dipole, with 10 feet of vertical radiator, needs no tuner on 40m, 20m and 10m and works fine on all bands above 40m with a tuner, and even below 40m on 60m, and 80m.

An F150 and Yaesu FT-857, ATAS-120 No-drill Install

Multiband Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna that work on 80m 40m 30m 20m 15m 10m. The Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna, developed by Serge Stroobandt, offers a versatile solution for amateur radio enthusiasts, covering multiple HF bands (80, 40, 30, 20, 15, and 10 meters) without the need for an antenna tuner. This innovative design utilizes a capacitor for resonance on the 80-meter band and a resistor to manage static charges. The CL-OCFD enhances bandwidth and simplifies operation, making it a significant advancement on OCF Dipole design.

Demonstrates the construction and performance of an updated ZS6BKW multiband dipole, a variant of the _G5RV_ antenna, specifically designed for HF operation. The article details a real-world installation using 13.5m copper wire elements and 12.2m of 450 Ohm ladder line, configured as a sloping inverted-V with the apex at 10m and ends at 4m above ground. It covers the critical aspect of impedance matching, incorporating an 8-turn choke balun at the feedline transition to RG-58U coax to mitigate RF common mode current. Measurements confirm favorable SWR readings below **1.3:1** on 7.1 MHz, 14.11 MHz, 18.06 MHz, and 24.8 MHz, indicating effective resonance across 40m, 20m, 17m, and 12m bands. The installation also shows usable SWR dips on 3.55 MHz (5:1), 29.02 MHz (2:1), and 50.84 MHz (3:1), extending its utility to 80m, 10m, and 6m with an antenna tuning unit. Initial on-air results report clear reception of stations over **5000km** away, validating its DX potential.

An easy to make trap dipole antenna for 40 and 20 meters

A delta loop wire antenna plan for the 7 MHz band (40 meters) that is quick to setup and work with

Four band lightweight antenna, that rolls up into an small Grundig antenna case by N0LX

A wire moxon antenna plan for the 7 Mhz

This article describes a low-cost, low-to-moderate power dummy load, which presents a 50-Ohm resistive load from HF through 440MHz.

Selecting an appropriate antenna system for shortwave broadcasting involves evaluating various types based on performance, cost, and operational parameters. This resource details the critical specifications for broadcast antennas, including average and peak power ratings, directivity, takeoff angle (TOA), horizontal beamwidth, and gain, emphasizing that a 100-kW transmitter requires an antenna rated for 150 kW average and 400 kW peak. It clarifies that low TOA signals travel thousands of kilometers, while high TOA is for local coverage, and nearly all modern shortwave broadcast antennas are horizontally polarized. The article explores specific antenna types, such as Log-Periodic Antennas (LPAs), which offer wide frequency ranges (e.g., 2-30 MHz) and directional patterns with 11 dBi gain, costing from $20K to over $100K for multi-curtain versions. Dipole arrays, also known as curtain antennas, are prevalent in international broadcasting, featuring steerable beams (±15° and ±30°) and mode-switching capabilities to alter TOA, with high/low pairs costing over $1 million. Fan dipoles are noted for omnidirectional patterns, smaller size, and lower cost for low-power applications, while rhombics, though simple, require resistive termination and incur several dB of I2R losses. Balun considerations are crucial, as most communications baluns are not rated for the higher average and peak powers of AM broadcast transmitters. Modern shortwave antennas utilize durable materials like Alumoweld wire rope for radiators and support elements, avoiding copper, fiberglass, or materials prone to stretching or deterioration. Feeder systems for high-power stations often require tapered-line baluns to convert 50-ohm unbalanced power to 300-ohm balanced for connection to the antenna.

A low cost, low profile DX antenna fro 17 Meters

FT2 is an innovative digital mode for amateur radio, developed by IU8LMC with support from ARI Caserta. It utilizes the same codec as FT8 and FT4 but compresses the transmission cycle to just 3.8 seconds, allowing for a complete QSO in as little as 11 seconds. This remarkable speed enables operators to achieve approximately 240 QSOs per hour, making it particularly advantageous for contests and DXpeditions. The FT2 protocol has been rigorously tested on-air, with successful QSOs verified down to -12 dB SNR on both 40m and 80m bands. The mode's efficiency and speed are a significant advancement in digital communications, providing a new tool for amateur radio operators looking to maximize their contact rates. As an experimental release, the software is subject to updates, ensuring continuous improvement and adaptation to user feedback.

The total length of this antenna is 41m, height is about 11m, and diameter of element is 2mm. JA7KPI modified this antenna originally used as Inverted-V type of 80m band Dipole. Works on 40 - 80 meters band with acceptable swr.

This page describes a homebrew 80/40 meter trap vertical antenna. Includes an interesting antenna raising system that allow easy setup and tuning.

The 30/40 meter **vertical antenna** project by IK4DCS details the construction of a shortened, self-supporting design, reaching a total length of 5 meters. The antenna incorporates a linear loading section and a coaxial cable trap for 30 meters, based on the "Antenne Volume 2°" text by Nerio Neri (page 223). The design uses six radials, three for each band, positioned at approximately 90° inclination and at least one meter above the roof or ground, connected via a 1:1 balun at the feed point. Mechanical construction utilizes aluminum tubing, with a 2.30-meter primary radiator section (30 mm diameter) joined to a second part using a Teflon insert and a PVC sleeve for rigidity. The linear load, approximately 3.70 meters long, accounts for a 30% physical shortening of the quarter-wave element. A capacitive load, made from three 50 cm radials, is integrated into the 40-meter top section for fine-tuning. Final adjustments involved radial inclination for 40 meters, as initial testing showed increased SWR and interference on 30 meters due to nearby resonant structures. The author emphasizes the importance of clear space for optimal performance and provides drawings and photos to clarify the build process.

Indoor multiband dipole with EZNEC data files for simulation and analysis. Includes details on construction, tuning, SWR plots, and software usage. This page includes two different dipoles, a first version for 20-10 meters and an extended version covering 40-10 meters allowing a full coverage of most used ham radio HF Bands.

RTTY by WF1B integrates terminal program functionalities with contest logging features, a design choice that proved highly effective in the author's field operations. It specifically supports a range of popular TNCs, including the AEA PK-900, MFJ-1278, AMT-1, and the HAM PCI4000/4100/3000 series, among others. This broad compatibility allows operators to leverage existing hardware investments while engaging in **RTTY** contesting. The software's dual nature streamlines the workflow for digital mode enthusiasts, eliminating the need to switch between separate applications for basic communication and contest participation. This integration is particularly beneficial during high-intensity **contests** where rapid logging and message exchange are critical. WF1B's creation addresses the practical needs of amateur radio operators seeking a dedicated solution for RTTY digital mode activities.

A simple dipole built for two-band operation can be used for portable use and operate 20 and 40 meter bands

This project started as a result of renewed interest in 40 meters coupled with the desire for an antenna system that would be more effective than the simple dipole.

Article by DK5WL describes a multi-band DX antenna for the 160m-40m amateur radio bands with low visibility but great performance for long distance communication.

40 Meter 2 Element Parasitic Delta Loop wire antenna with pictures of delta loop assembling

Vertical antennas for all HF bands, expecially 80 40 20 meters bands

A reversable quad antenna for 40 meters band by N4JTE

Three eh antenna plans for 20 40 meters bands.

Drawings of shortened antenna for indoor usage, using short pvc tubes for 2 , 20 and 40 MHz by f1rfm

This project uses a widely available IRF510 MOSFET, work on HF 80, 40, 30, 20 and 17 meter bands

Build a Multi-Band Mono Delta Loop for 40, 30, 20 and 15 Meters.

A helically wound two element 40 meter yagi beam antenna from a 1974 QST article

This PDF File desscribes how to homemade a multi-band end-fed trapped wire antenna resonating on the low bands of 160 80 and 40 meters. Contains trap design instructions and some construction tips.

This document by W4HM explains the construction and usage of a 160 meter balanced coaxial receiving loop antenna, which can be easily adapted for the 40 and 80 meters bands. The content provides detailed instructions on building the antenna, its advantages, and how to optimize its performance for amateur radio operations. It is a valuable resource for radio amateurs looking to improve their receiving capabilities and enhance their overall radio communication experience.

Vintage and reproduction electronic parts specialist - antique radio dials and knobs, 1940-1970 era phonograph cartridges, needles, idler wheels.

Wire antenna for 10-15-20-40-80 meters band, with many drawings and description in spanish

A loopy loop loaded vertical antenna operating range 7.0 to 7.3 MHz by S. C. Chuck Smith, WA7RAI

There are many ways to support an amateur radio antenna. Installatio of a utility pole will provide an antenna height of approximately 13 meters (40 feet) and will require no guy wires.

The K9GDT 40m receiver

Solid State and TWT Amplifiers From 1 MHz to 40 GHz with Power Levels from .1 mil Watt to 2.5 Kw