swr protection/cache

JA7KPI Windom antenna for 40-80 - 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.

Wire Antenna for 75 and 80 Meters - This article is about a wire antenna that covers the entire 3.5 to 4.0 MHz band with an SWR below 2:1 consists of two coupled dipoles, one resonant at about 3.5 MHz and one resonant at about 4 MHz, resulting in the low SWR

Simple HF Baluns for 50/75 ohm coax - 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.

Antenna Feeders - Different types of feeders, SWR and matching

Tuning Your Antenna - Getting the best performance from your investment

The Coaxial Line - Impedance matching, Transmission Lines, Characteristic Impedance, VSWR & Mismatch and Antenna Losses

Log Periodic of Another Sort - A log periodic dipole array (LPDA) antenna design that offer continuous low SWR in 13-30MHz range

Tuning moxon antennas - More on the tuning of Moxons, getting the best F/B ratio and the lowest SWR, moving the feeding point and other constructions considerations

Vertical antenna for Vacation - Vertical Vacation Antenna for 80, 40 and 20 Meter-Band, by Herbert OE3BMB This antenna is a full size λ/4 for 20m and 40m band, and a shortened λ/4 for the 80m band. Generally on the 40m band the SWR is under 1,6. In 80m and 20m band at the resonant frequency the SWR is about 1,1.

Musings on the Miracle Whip design - A modified design of this popular portable antenna The whip described here will tune up to a respectable SWR on 40 metres and up.

Matching Waves, VSWR at work - When the radiation resistance (voltage to current ratio) of an antenna is the same value as the characteristic impedance of the transmission line (voltage to current ratio in the line), all of the electrical energy transmitted down the line is taken by the antenna and radiated into space in the form of a radio wave.

Yagi antenna Q Factor - How you can calculate antenna Q factor for use in antenna quality evaluation instead of use of VSWR bandwidth.

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

Automatic SWR meter - Automatic SWR meter and semi-automatic tuning unit by F1FRV

10 m Aerial Matching Unit - This simple matching unit will allow a 10 meters aerial to be used right across the 10m band without the need to physically adjust the elements, and offers a virtual 1:1 VSWR at 50 ohms impedance to the transmitter.

Antenne verticale HF. - A vertical antenna project than can present low swr from 40 to 10 meters by using a balun in french

OK1DX Pavel - Personal web page with some electronic projects like rotator controler AVROT, SWR Mega meter and personal amateur radio information

HB9FX Internet Remote Base JN37XH Hochwacht Zofingen Switzerland - Tune and / or listen between 10kHz - 10GHz to professional Online-Receivers as Rhode & Schwarz EK070 or AEG E1900/3, Amateur-Radio-Transceivers, Web-SDR, Digital-Modes, Repeaters, EchoLink, APRS or control Antenna-Switch-Matrix, Antenna-Tuner, SWR & PWR- Control or Web-Cams.

MFJ Enterprises  ^pop - MFJ manufacturer of ham radio antenna products, antenna tuners, antenna analyzers, morse code & CW, SWR wattmeters, antenna accessories , power supplies, audio filters, TVI filters, baluns, coax switches and more

Ningbo Zhongce Dftek Electronics - SWR meters, Power supplies, millivoltmeters, Oscilloscopes, signal generators, function generators China.

A Guide to Test Equipment - That just about sums up many peoples’ attitude towards test equipment. Multimeter, SWR/Power Meter, Dip Oscillator, RF Signal Generator, Cathode Ray Oscilloscope

MeterMate - SWR Graphing Software for Amateur Radio by KD4UDY, shareware

Very simple wattmet - A very simple QRP wattmeter project by SP5DDJ based on schematic of SWR meter developed and published by JA6HIC

A QRP SWR meter - A real QRPp VSWR Meter project by DJ1ZB

A simple SWR Meter - This article describes a simple QRP SWR meter built using readily available parts.