Search results

The antenna is a 10 - 160 meter horizontal loop fed with 450 ohm ladder line all the way into the ham shack to an Palstar AT1500BAL balanced line antenna tuner

A 10-20 meters coverage delta loop antenna. After relocating, DL2HCB designed a multiband loop antenna to cover 10-20m with an open-wire feed for impedance matching and compact installation. Inspired by the mini-X-Q design, a modified 10m delta-loop was built, enhanced with a 1/4 wave shorted stub for 28 MHz using 450-ohm ladder line. The antenna delivers east-west broadside radiation and performs as a closed loop on other bands. Operational tests yielded strong European signals and successful DX contacts, including a 20m QRP QSO with FY/DJ0PJ.

PDF article about a coaxial 1:1 balun, original concept by I4BBE using a quarter-wavelength and the three-quarter-wave adapting sections with the 50-Ohm coaxial cable by I0QM

Here is a sure fire way to make end-fed halfwave antennas fed with a 50 ohm coupler work - without long radials, grounds, chokes, voodoo.

Great first time J-pole project. Covers most of the basics. This small and thin design also makes it good for several stealth applications.

Show diagrams, winding methods and tables of some 1:1 and 4:1 baluns for 1.8 - 30 MHz suitable for use up to 200W (400W peak) on systems using 50 or 75 ohm coaxial cable input where SWR should not exceed 1.6:1.

Make your own dummy load with two 100-ohm 5W resistors

This article describes a 10 watt linear amplifier that is capable of delivering over 15 watts into 50 ohms and uses cheap plastic transistors that are used in CB equipment. by Harry Lythall - SM0VPO

This project details three variants of a vertical half-wave antenna design for the 4-meter (70MHz) amateur radio band. The antennas use end-feeding with a parallel-tuned circuit for impedance matching to 50-ohm coaxial cable. The first variant uses suspended flexible wire for portable use, the second employs a fiberglass rod with internal wire for permanent outdoor installation, and the third utilizes aluminum tent poles for quick mobile deployment. Despite the narrow bandwidth of the matching circuit, this suits the narrow 4m FM allocation well. The design offers an effective omnidirectional radiation pattern and can be constructed with readily available materials.

How to make 450 ohm open feeder

The Double Bazooka Dipole is a very efficient single band antenna which is very quite, and does not require the use of a balun. This antenna consists of coax (RG58) or other 50 ohm type with the shield split at the center and the feedline attached to the open ends

The Windom is an Off-center wire multiband Antenna. The old version was fed just by a single-wire connected on 1/3 of antenna's overall length or with an open-line feeder (later versions). Here is another model with coaxial feeder, which is compatible with Solid States - 50 Ohm output transceivers .

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

This homebrewed antenna tuning unit also incorporates a 50-ohm QRP dummy load, power meter (1 or 10 Watts full scale), and SWR meter

This article addresses the subject of obtaining the best signal transfer from an antenna to the typical 50-ohm receiver input over a wide frequency range, with emphasis on medium-wave (500 - 2000 kHz), encompassing the standard AM broadcast band and the 160-m amateur band.

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.

This wire-beam has one radiator-element, feeded with 450-Ohm-Wireman-twinlead and needs an antenna-tuner. For the bands 6m, 10m, 12m, 15m, 17m and 20m bended reflector-elements are used. The support is a cross of 4 fibreglass-fishing-rods

An AO-10 antenna by K5OE, this design is optimized for 436.8 mHz with a 50 Ohm feed

MoxGen will show you the dimensions and generate an antenna model file for a 50 ohm Moxon Rectangle antenna, given the design frequency and wire size

Wire antennas requires a special coupling network to properly couple my 50 ohm coax to the antenna's high impedance (5000 ohms)

The beam has only one feedpoint with 50 Ohm and has an open-sleeve element for 12 m by DK7ZB

Low-cost 600:50 Ohm Baluns by Andrew Corney ZL2BBJ

Portable Vertical Antenna for 75m and 40m featuring Low radiation angle for DX, easy to install and to match 50 ohms

The "Tenna Dipper" is a low power antenna analyzer and ATU tuning aid. With this handy accessory, you can determine the 50 Ohm resonance frequency of antennas or you can adjust your antenna tuner for a 50 Ohm match without generating QRM

The Dual-Band Wire Beam was inspired by L.B. Cebik's (W4RNL) article The Elusive Moxon Nest. Fiberglass tubing spreaders, Flexweave elements, an aluminum hub, and two die-cast aluminum flanges combine to provide a 12/17m Moxon nest with one 50 ohm feed.

a neat 1:1 50 ohm balun for use on HF horizontal wire dipoles.

This project is intended to aid in tuning a balanced antenna or feedline that has a high impedance 100-600 ohms

The Moxon Rectangle is growing in popularity as a compact 2-element array that approaches a full-size 2-element in gain but with a far superior front-to-back ratio and a direct match for the standard 50-Ohm coaxial cable.

Antenna was designed for SO-50 satellite operation but can be used for any VHF/UHF activity. It's a mix of a Moxon Antenna and a Yagi antenna. It has gains 4 dBd on 2m and 6.5 dBd on 70cm bands and it is fed via single 50 Ohm cable.

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.

This simple 30m QRSS beacon is built entirely out of junkbox parts, the only component purchased specifically for this project was the 10,140kHz crystal. Hans Summers' 30m QRSS beacon project emphasizes simplicity and low cost, built almost entirely from reused parts. Key components include a 10,140kHz crystal, a 2N3904 transistor from a broken DVD player, and an ordinary LED used for frequency shift. The oscillator is stabilized in a polystyrene box, with power amplification driven by recycled copper PCB. Output power peaks at 360mW, and a custom 50-ohm dummy load manages heat. Though aesthetically unconventional, the beacon works effectively, fulfilling the project's low cost aim.

In this article the schematic is of AA5TB QRP power meter and dummy (50 Ohm) load combination

Solves antenna matching problem with two phased antennas. Stacked rotary beams are popular. However, connecting two 50 Ohm antennas together presents some problems.

An impedance transformer (9:1) to feed a high impedance long wire (~450 ohm), down to a 50 ohm unbalanced coaxial input.

A 10 meters band Slim Jim antenna project, made with a 450 Ohm slotted ribbon cable and secured on a 8 m fishing pole, by Steve G0KYA

How to Build a ZS6BKW Antenna, an optimised version of the popular G5RV multiband Antenna, basically a random length dipole with a 450 Ohm ladder line acting as a 1:1 transformer by VK4MDX

On this page is the design for Dual Band 2M / 70cm antenna with 3.2mm elements. The antenna has a 50 ohm designed driver. This Yagi has a unique element called a Open Sleeve

A homebrew dummy load is usually a combination of several parallel carbon resistors, in order to be able a final resistance of 50 Ohms.

YF1AR multiband vertical antenna, based on orginal concept by VE7BS. Consist of 6 vertical elements and 6 base radials with a single 50 Ohm feed line.

Construction details of a multiband dipole that can can operate at high power levels, and match its 50-ohm coax feedline without a tuner

If your doing any home brewing gear for ham radio its a great idea to have a dummy load. This will to your radio be the perfect antenna...it will never radiate but your radio sees a perfect 50 Ohm impedance.

CO2KK exposes some myths about using 75-ohm feedline with 50-ohm rigs and show how to build a cotanget transformer

This is a simple portable 2-meter J-Pole antenna. You start with a piece of 450-Ohm Ladder Line

This Duoband-Yagi has a boom of 3.60 m and 3 elements for 10 m 4 elements for 6 m and one feedpoint with 50 Ohm

A home made dipole antenna for 10m, 6m, 4m bands made with two sections of 450 and 300 Ohm ladder lines, cut to achieve acceptable SWRs on all bands

A simple 50 ohm dummy load to test transmitters. includes a simple RF diode detector to measure the peak voltage, and calculate the power

C-Poles for 20m and 6m, it is a folded half-wave dipole with an asymmetrical tapped 50-Ohm-point in the lower part of the antenna. Design hints by DK7ZB

A 5 element yagi beam antenna for ten meters band with full dimentsions, eznec file and coax match informations for 50 ohms feed line

This antenna article is geared towards new Hams and antenna builders looking for a very inexpensive 6 band antenna that can be efficiently fed with 50 ohm coax without a tune

The **136kHz Vertical Antenna** at G3YMC employs a Butternut HF2V structure, standing 10m tall. It integrates a 6.5mH loading coil to achieve resonance, with a matching transformer for impedance adjustment. The antenna's configuration includes top loading via a 12m horizontal wire, enhancing capacitive impedance. Initial measurements indicated a high impedance of around 300 ohms, necessitating a transformer for a 50-ohm match. Despite challenges with ground losses, the vertical antenna has shown improved performance in specific directions, filling nulls present in the previous loop antenna setup. The tuning remains broad, with variations due to environmental factors affecting the matching. Ongoing adjustments and comparisons with the loop antenna will continue to refine its effectiveness.