Search results

The secret with this antenna is to install as many radials as you can around the base of the antenna, they can be anything from 1/8 wave or longer.

Presents a collection of homebrew amateur radio projects and circuit ideas developed by EA5/G3PTO, a licensed operator since 1961. The resource details various transmitters and receivers constructed for frequencies ranging from 1.8 MHz to 10 GHz, emphasizing CW and BPSK31 operation. Specific projects covered include a "Bombproof 7Mhz Receiver" and several keying circuits, providing insights into designs that have proven effective over decades of use. The site also integrates personal photography, showcasing scenes from the West of England and Southeast Spain, reflecting the author's interest in connecting with other amateurs and visualizing their locations. Additionally, it offers a curated list of links to other home construction sites and DX information, serving as a hub for DIY enthusiasts and DXers. The content is distinctively personal, blending technical project documentation with a broader view of the amateur radio lifestyle and community engagement.

AM/FM/CW QRP RF Power Amplifier for the HF 10 or 11 meterband (28MHz/27MHz)

Building a 40m (7MHz) horizontal delta loop wire antenna in the backyard that is easy and quick to setup

Includes EH antennas, 7Mhz vertical monopoles, 5 elements vee log-yagi for 10m and more

A coaxial cable tuneable magnetic loop antenna for 7MHz. This experimental antenna does not require a tuning capacitor

This article documents an unobtrusive antenna for operation on 7MHz, primarily for contacts with stations at up to 1000Km range.

How to build a ground plane antenna for the 40 meters band in french

Constructing a Lindenblad antenna for 137MHz NOAA satellite reception involves specific design considerations for optimal performance. The resource details the use of 4mm galvanised steel fencing wire, 300-ohm television ribbon cable, and wood/plastic components for the antenna structure. Key dimensions for a 137.58MHz-resonant antenna are provided, derived from the ARRL Satellite Handbook, specifying s, l, w, and d as 42, 926, 893, and 654mm respectively. The antenna is designed for Right Hand Circularly Polarised (RHCP) signals, requiring the four folded dipole elements to be tilted clockwise by 30 degrees. A significant aspect covered is impedance matching between the antenna's 75-ohm impedance and a typical 50-ohm receiver input. A twelfth-wave matching transformer, constructed from 117mm sections of 50-ohm RG-58 and 75-ohm RG-59 coax with a 0.66 velocity factor, is described. The article also addresses coaxial cable and connector selection, recommending 75-ohm Type-N connectors for RG-6 cable in professional setups and F56/F59 connectors for general use, while strongly advising against PL-259/SO-259 connectors for VHF. Strategies for mitigating Radio Frequency Interference (RFI) are discussed, including antenna placement to shield from local TV transmitters and the use of commercial or DIY band-pass filters, such as cavity resonators or helical notch filters, along with ferrite chokes on coaxial cables. Antenna orientation is explored, noting the Lindenblad's 'cone of silence' directly overhead and its maximized sensitivity towards the horizon. An experimental vertical tilt of 90 degrees is presented as a method to improve overhead reception and reduce interference from strong horizontal signals, particularly relevant in high RFI environments like the Siding Spring Observatory site.

This antenna allow transmission and reception on all bands between 7Mhz and 28 Mhz. Similar in concept to the Miracle Whip by VK3YE

This article describes the design of an antenna for local contacts on 7MHz, including a simple and efficient matching system that presents a 50 ohm load to the transceiver.

VU2VWN project to homebrew a CW for 40 meters band

A 7MHz Full wave loop antenna in diamond shape for field day operations made with three 31 foot Jackite poles

A vertical dipole for 7MHz and 21MHz by OH3GGQ

Dutch web site dedicated to freebanding on 27 mhz.

The GM4JMU Shortened 7Mhz Dipole

An homebrew project of a full wave delta loop antenna for the 40 meters band with dimensione, picture and assembling instructions in Indonesian

A vertical antenna project for the 7MHz made with some spare parts. Based on a broken 20 foot fishing pole, it is based on a good ground system made with radials and a capacitive hat done to increase the global radiation resistance of the antenna. A custom loading coil is also included in this project to perfectly tune the antenna to the CW portion of the 40 meters band.

A 40 meter QRP - Transceiver by DL5NEG

High Frequency Expermental Beacon "WV". The Beacon operates on the frequency of 13.55567mhz. This Beacon is very low power. It operates under Part 15 of the FCC Rules and Regulations. It transmits with only 1.5 milliwatts of power

JA6YBR/b in Miyazaki, JAPAN operating on 50.017MHz

A multi-band off centre fed dipole, designed to operate on all bands from 40m (7MHz) to 6m (50MHz). Author claims it will operate on 40, 30, 20, 17, 15, 12 and 10m without an ATU (SWR <3:1) plus 6m with an ATU.

This page details (in brief) the component changes to modify a Cybernet series 27MHz CB transceiver to 50MHz.

A portable loop antenna, made with a 3 meter loop resonates with the chosen capacitor from just below 7MHz to about 28.300MHz which makes it usable on the bands from 40m to 10m.

Nuand bladeRF 2.0 Software Defined Radio (SDR) 47MHz to 6GHz, 2x2MIMO, 61.44MHz sampling

Learn how to build a compact and efficient HF antenna for ham radio operators with limited space. Follow the author's journey from experimenting with different antennas to creating a magnetic-mounted antenna that covers 7MHz to 30MHz without the need for an ATU. Discover how a portable flagpole can be repurposed for radio communication, allowing you to operate with 100 Watts power output. This project provides a cost-effective solution for hams looking to set up a reliable antenna on their car roof in just 30 seconds.

This article discusses a high performance, 7MHz, 5 watt SSB rig, the Daylight Radio, an all-analog radio design from the 1980s that includes a full circuit diagram, IMD NR60 calculations, QER crystal filter, bandpass filter, receiver portion, and more. The author explores the design, components, and functionality of this analog radio for hams interested in vintage or homebrew radio projects.