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HF Bands QRP linear amplifier by SM0VPO

a simple, low-cost, trapless short vertical antenna which amazingly works on three HF bands (20, 15 and 10 meters)

10-12-15-17-20m A description was in the German Ham-Magazine "Funkamateur" in Issue 11/2003

To build this antenna you need a lot that is at least 100 feet across. Antenna covers all bands 80-10 meters + 30, 17, 12 meter WARC Bands

WSJT-X implements communication protocols including FST4, FST4W, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, WSPR, and Echo. These modes facilitate reliable, confirmed QSOs under extreme weak-signal conditions. JT4, JT9, and JT65 utilize a nearly identical message structure and source encoding, employing timed **60-second** transmit/receive sequences synchronized with UTC. JT4 and JT65 are designed for EME on VHF/UHF/microwave bands, while JT9 is optimized for MF and HF, offering **2 dB** greater sensitivity than JT65 with less than 10% of its bandwidth. Q65 provides submodes with varying T/R sequence lengths and tone spacings, suitable for EME, ionospheric scatter, and weak signal operations on VHF, UHF, and microwave. FT4 and FT8 operate with T/R cycles of 7.5 and 15 seconds, respectively, supporting enhanced message formats for nonstandard callsigns and contest operations. MSK144 is engineered for Meteor Scatter on VHF bands. FST4 and FST4W target LF and MF bands, achieving fundamental sensitivities near theoretical limits for information throughput; FST4 is for two-way QSOs, and FST4W for quasi-beacon WSPR-style transmissions, without requiring the strict time synchronization of protocols like _EbNaut_. WSPR mode enables propagation path probing via low-power transmissions, incorporating programmable band-hopping. The **WSJT-X 2.7** General Availability release introduces the QMAP program, Q65 Pileup, SuperFox mode, a Hamlib update option, and a Message System. SuperFox mode transmits simultaneously to up to 9 Hounds with a constant envelope waveform, providing approximately +10 dB system gain compared to older Fox-and-Hound operations. _WSJT-X 2.7_ for _Windows_ platforms includes _MAP65 3.0_, a wideband polarization-matching tool for EME. The **WSJT-X 3.0.0-rc1** candidate release represents a major revision with new features, some ported from _WSJT-X Improved_. This software is available for _Windows 7_ and later (32-bit/64-bit), various Linux distributions (Debian, Ubuntu, Fedora, RedHat, Raspberry Pi OS), and macOS (10.13 through 15). DXZone Focus: Weak Signal | Digital Modes | WSJT-X | Windows

Magnetic loops are a compromise antenna and performance will be down on a full size-wire antenna particurlarly on lower HF Bands. This article compare this magnetic loop with a full-sized wire antenna on 80 meters by VK3YE

A guide from 0 Hz to 30 MHz The main bands, all frequencies in MHz unless otherwise stated

This antenna is not a true Windom, but rather an off center fed or OCF dipole works on 8 bands from 80 to 10 meters

Download this color US ham radio band-plan in PDF format edited by ARRL

This sketch will read RF power and SWR from any SWR bridge, designed to work on VHF UHF bands

amateur radio bands and band restrictions

Presindet Electronics produces all mode CB bands transceivers, antennas, and accessories.

This small tuner by KC8AON has only 2 controls and will tune almost anything from 10 to 80

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.

This web page describes a small, single tuned circuit regenerative receiver primarily for daylight reception in the 16, 19, 22 and 25 meter international shortwave broadcast bands.

The page provides detailed information about the construction of a full-size 160M 3 element beam antenna and an 80M 5 element beam antenna on a 330ft tower. It includes specifics about the tower height, types of antennas, elements, gain, take off angles, front-to-back ratio, operating frequencies, weight, and dimensions of the beams. The content is aimed at amateur radio operators interested in building high-performance antennas for the 160M and 80M bands. This Antenna is now been destroyed and is no more operational.

Quad, Yagi for low bands. Specialist in antennas, supports and moving of medium-large sized radio antennas, professional rotators, masts, towers, and accessories.

Description of a delta loop antenna for HF bands in french

Simplified U.S. frequency allocations table by K8ZT

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

Some tens of very special audio files recorded during amateur radio activities like aurora traffic, meteor scatter, communications with ISS crew and the sound of various transmission modes that you can hear on HF and VHF bands

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.

CW Skimmer 2.1 employs a high-sensitivity CW decoding algorithm based on Bayesian statistics, enabling simultaneous decoding of up to 700 CW signals within a receiver's passband on a 3-GHz P4 system when paired with a wideband receiver. The software features a fast waterfall display with sufficient resolution for visual Morse Code interpretation, automatically extracting and labeling callsigns on the waterfall traces. Extracted callsigns are exported as DX cluster spots via an integrated Telnet cluster server. The application includes a DSP processor with a noise blanker, AGC, and a variable-bandwidth CW filter, alongside an I/Q Recorder and player. It supports both 3 kHz radio passbands and wideband SDR receivers like SoftRock, RF Space SDR-IQ/SDR-14, SRL QuickSilver (QS1R), HPSDR Mercury, and Microtelecom Perseus. System requirements specify Windows XP/7/8/10 (32-bit or 64-bit), a Pentium-4 2.5 GHz for wideband operation or 1 GHz for 3-kHz radios, a COM port for CAT control, and a stereo sound card supporting 48 kHz sampling. It integrates with Elecraft KX3, Icom IC-7300/IC-7610, and Flex 6000 series radios, with documentation available for various setup configurations.

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.

A very easy to use program to decode DTMF dial tones found on telephone lines with touch tone phones. The DTMF Decoder is also used for receiving data transmissions over the air in amateur radio frequency bands.

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

Suitable antenna for owners of an IC706 or FT817, 857 and other HF portable transceivers. You can an be QRV in a few minutes on all ham-bands from 80m to 6m and even on 2m by PA0FBK

The Inverted L antenna is a versatile and efficient design suitable for small gardens, allowing amateur radio operators to operate on multiple bands. This project outlines the construction of a 5-band inverted L antenna, which can cover HF bands effectively. The design is particularly advantageous for those with limited space, as it requires minimal ground space while providing good performance. The antenna can be easily constructed using common materials, making it accessible for both beginners and experienced hams. In this guide, GM0ONX shares detailed instructions on how to build the inverted L antenna, including dimensions and tuning tips. The project emphasizes the importance of proper installation and grounding to ensure optimal performance. Additionally, it discusses the antenna's compatibility with various transceivers and the potential for portable operation. This resource is ideal for hams looking to enhance their station with a multiband antenna that performs well in limited space.

Multi-band centre-fed antenna capable of very efficient operation on all HF bands, specifically designed with dimensions which allow it to be installed in gardens and other open spaces which accommodate a reasonably-straight run of 31.1m (102 ft) for the flat-top standard model.

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.

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

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.

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

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.

Three eh antenna plans for 20 40 meters bands.

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

A small and inexpensive measurement device designed to determine antenna performance across the amateur bands through use of automatically collected SWR readings

This Multiband Cubical Quad antenna a boomless Quad design with glass-fibre arms and a single coax wire connected to a remote antenna switch. This aerial work on 8 bands and has a 60-degree beam width. Despite achieving critical technical requirements, the antenna's three-dimensional structure presents obstacles, such as installation issues on fixed towers and risk of frost damage. The spider framework is built of stainless steel, with a compact 18-inch boom and strong angle iron arms. Tait use a variety of methods to fasten element wires and suggests placing them on the outside of the spreaders for improved insulation. The use of nylon twine or parachute cord between key attachment points allows for adjustable separation between pieces.

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.

Hammock 2 element wire Yagi antenna for 3 bands 20-15-10 based on VE7CA project

The document is a PDF detailing the construction of the DBJ-1 VHF-UHF Dual Band J-Pole antenna for amateur radio use. It provides instructions on how to build a high-performance dual band base antenna for VHF and UHF bands using a single feed line for less than $10.

This project shows how to build a 50-ohm dummy load using non-inductive resistors, oil for heat dissipation, and a simple assembly process. It enables accurate transmitter tuning, testing, and power measurement across LF to UHF bands. The setup allows meter calibration by measuring peak voltage, applying diode drop correction, and calculating RMS voltage and power precisely. Parts are inexpensive and widely available. With proper assembly, this dummy load offers extended service life, accurate readings within 2%, and a reliable alternative to costly commercial wattmeters for amateur radio applications.

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

The G3TPW Cobwebb antenna covers five bands, 14 - 28 mhz, including the WARC bands

The Petlowany Three-Band Burner is a simple, low-cost, trapless short vertical antenna which amazingly works on three HF bands (20, 15 and 10 meters). This web page contains pictures, performance data, and enough construction details so you can homebrew your own.

2-Element parasitic Yagis for the Shortwave-Bands 10m-30m

The H-Pole is a vertical multiband wire antenna for 160-10 meters bands

Here is a circuit that will resonate a short whip antenna for the HF Bands.