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Build a space efficient trapped dipole antenna for 40-80-160 meter bands using RG-58 and PVC pipe. The document provides a brief guide on building a compact dipole antenna appropriate for the 40, 80, and 160-meter amateur radio bands. It explains the materials, building processes, and tuning methods required to provide best performance while preserving space. The paper also discusses theoretical elements of dipole antennas, such as impedance matching and feedline selection.

This PDF article from April 2001 QST details the construction of the "NJQRP Squirt," a reduced-size 80-meter inverted-V dipole antenna. The resource provides a general construction sketch, a photograph of the assembled antenna, and specific dimensions for PC-board insulators. The antenna consists of two wire legs, each approximately **34 feet long**, separated by 90 degrees, fed at the center. It is designed for operation on 80 meters (3.5-4.0 MHz) as a quarter-wavelength antenna, requiring a low-loss feedline and an external antenna tuner due to its non-resonant feedpoint impedance. Construction utilizes readily available materials, including 1/16-inch glass-epoxy PC board for end and center insulators, and #20 or #22 insulated hookup wire for the elements. The feedline specified is 300-ohm TV flat ribbon line, with a note on potential trimming for tuner compatibility. N2CX reports the antenna's center should be elevated to at least **20 feet**, with ends no lower than seven feet above ground, resulting in a ground footprint of approximately 50 feet wide. The design prioritizes NVIS propagation for local 80-meter contacts. DXZone Focus: PDF Article | 80m Inverted-V Dipole | Construction Notes | 34 ft element length

Here you will find many information on loop antennas.

A comparison of different multi-band dipole techniques

A short but efficient dipole for 40 meters band

Cannot find the inductors you need for an antenna, a tuner or amplifier ? Build your own it is easy!

Large aurtralian radio frequency charts collection

Monitoring shortwave broadcast stations effectively requires accurate schedule information to identify transmissions. This online utility offers a straightforward, graphical interface designed to search for and display current shortwave radio broadcasting schedules. Users can precisely filter results by frequency, specific language, broadcaster, time of day, and even by shortwave band, which simplifies the process of pinpointing desired content. The database, last updated on March 26, 2023, details station callsigns (e.g., BBC), start and end times in UTC, days of the week, broadcast language, transmitter power in kilowatts, and azimuth. Crucially, it includes the precise geographical coordinates of transmitter sites, such as Woofferton in the UK or Al Seela in Oman. This data is invaluable for predicting signal paths and optimizing antenna direction for improved reception, a key consideration for serious SWLs. For instance, a search for BBC English broadcasts at 21:04 GMT quickly reveals multiple active frequencies like 17780 kHz from Woofferton, offering a clear overview of current transmissions. The tool processes queries rapidly, returning results within seconds, demonstrating its efficiency for broadcast listening enthusiasts seeking timely information.

Suggestions on finding RF ground when you live in an apartment and you want to setup an antenna

Which balun to use? The hybrid balun promises advantages over both voltage and current baluns by ZS1AN

Determining the actual need for an antenna tuner often hinges on the specific antenna and feed line configuration in use. While many hams believe a tuner is always essential, its primary role is to present a 50-ohm impedance to the transceiver, not to "tune" the antenna itself. For instance, a resonant dipole fed with _coaxial cable_ at its design frequency typically requires no tuner, as the feed line impedance closely matches the radio's output. However, operating a non-resonant antenna, or using a resonant antenna on multiple bands, frequently necessitates a tuner to manage high Standing Wave Ratio (SWR) on the feed line. The article clarifies that a tuner placed at the transceiver only matches the radio to the feed line, not the antenna to the feed line. For maximum efficiency with a non-resonant antenna, an _automatic antenna tuner_ (ATU) or a remote tuner placed at the antenna feed point is often more effective, minimizing losses in the feed line. The discussion also touches on the practical implications of SWR, noting that modern transceivers often fold back power at high SWR, making a tuner a practical necessity to achieve full output power, even if the antenna itself is not perfectly matched.

The Beverage antenna was invented in the early 1920s by Dr. Harold H. Beverage

Usage and benefits of transmatch. A pdf document from a QST article made available for novices and beginners by ARRL

How antenna works by ARRL

An inexpensive external GPS antenna, for 1.5 GHz band for GPS receiver, If you operate APRS or just need an external antenna for your GPS receiver, here's one that is easy to build yet offers surprisingly good performance in a compact size. Best of all, it uses commonly available components and materials.

Ferrite Toroidal Cores, Magnetic Properties of Ferrite Materials, EMI - RFI Suppression Design Considerations, Ferrite Beads, Ferrites for RFI Ferrite Cores for RFI Suppression by CWS ByteMark

Service information, modifications, diagrams, manuals and schematics, and technical files on Galaxy DX Radios.

What is a dipole antenna and why are they so popular ? Arrl PDF file

Service information, manuals, diagrams pictures and schematics, and technical files on Cobra Radios

A few hours of fun with PVC and wire and you have got yourself a respectable road radiator. The antenna consists of little more than some PVC pipe topped by a RadioShack replacement whip antenna and a couple of coils made from a small roll of #14 house wire.

How to select an antenna for scanning. This is a Readers Digest version of antennas, meant to give new users some idea of the different antennas and their good and bad points.

IRAQ War Military HF freqs, Aero HF frequencies and Shortwave Broadcast schedules of interest

About grid locators and grid squares, includes links to locator and grid square calculators

Frequency table for 900Mhz phones

A modern version of the classic regenrative receiver designed and built by Charles Kitchin ARRL Article

Service maual for Icom IC-718

A 10-meter J-Pole antenna, detailed in QST February 1950, offers a straightforward solution for hams operating with restricted space. This design, originally presented by W1BLR, is a **half-wave radiator** fed by a quarter-wave matching stub, providing a low-angle radiation pattern beneficial for DX. The article describes building the antenna from readily available materials like copper pipe, emphasizing its simplicity and effectiveness for **single-band operation**. The J-Pole's inherent design provides a good impedance match to 50-ohm coaxial cable without the need for an external tuner, a significant advantage for portable or minimalist stations. Its nondirectional pattern ensures coverage in all directions, making it a versatile choice for general operating on the 28 MHz band. The construction plans are clear, allowing even those with basic workshop skills to assemble a functional antenna.

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.

William Hepburn's Daily Tropospheric Ducting Forecast.

WA5FRF VHF mobile antenna for bicycle installation

Turn your android mobile phone or tablet into an affordable and portable software defined radio scanner

A 20 meter quarter wave vertical antenna by jerry sevick W2FMI QST Article

Building guide for a two element quad antenna planned for 28 and 21 Megahertz

a portable 2 elements tri band yagi

Signals Analyzer it's a a program, which is designed for the very qualitative analysis of different signals. The one of main fields of SA application is the analysis of unknown or unclear, strange signals. This programm will be very usefull to everyone from professional analysts to amateurs.

Source of common model manuals and amateur help on amplifier problems for the amateur bands, Discussion of vacuum tube amplifiers. Technical information and discussion of obselete tube replacement.

Simple gain antennas for the beginner, a 2 element HF yagi antenna

Make your own rf step attenuator

Do your multiple-transmitter field day or contest efforts suffer from intrastation interference ?

Signals Analyzer it is the program, which is designed for the very qualitative analysis of different signals. The main area of SA application is the analysis of unknown or unclear, strange signals.

Demonstrates the construction of a **homebrew spectrum analyzer** designed by Wes Hayward, W7ZOI, and Terry White, K7TAU, enabling radio amateurs to build a capable test instrument without significant expense. The resource details a _double-conversion superheterodyne_ circuit, employing intermediate frequencies of 110 MHz and 10 MHz, and covers essential blocks such as the time base, logarithmic amplifier, resolution filters, and local oscillators. It highlights the use of hybrid and monolithic ICs, including mixers, amplifiers, and VCOs, to simplify construction while maintaining performance. The design supports useful measurements in the 50 kHz to 70 MHz range, with methods outlined for extending capabilities into VHF and UHF. The authors emphasize that this analyzer, while simple to build, is intended for serious measurements, requiring careful control of signal levels to avoid spurious responses. It uses an oscilloscope for display, with specific instructions for calibration and adjustment of various stages, including the log amplifier and IF gain. The guide provides detailed schematics and component lists for each section, such as the 110 MHz triple-tuned band-pass filter, which achieved **90 dB** image rejection, a significant improvement over double-tuned circuits. Practical advice on alignment and troubleshooting is included, drawing on the authors' extensive experience in RF circuit design.

RFI/EMI RadioFrequency interference/electromagnetic interference by ARRL Technical Information Service page

Common faults, and modifications for the kenwood TS-430 S

1993 QST Article of a 2 meter beam antenna by WB0CMT

Article shows how to develop a good external ground system to complete your station's protection.

Technical questions answered about grounding techniques, in pdf file

Schedules and local radios broadcasting from and to Iraq during war.

In this site SWL can find many thing he needs: Contest rules and results, software, awards info and photos, forums, chat and more.

If you are looking for an easy antenna for your favorite band, you can't go wrong with an halfwavelenght dipole, all you need is 3 insulators and some wire

A direct drive ring radiator antenna for the 40 meters band by W6WYQ QST article.