Radio Frequency Interference

Idiot's guide to coaxial cable - A very beginner's guide to coax cables. Characteristics, detailed comparison of typical coaxial cables, commonly used connectors, and a few words about SWR.

RFI Information Page - This page gives information about Radio Frequency Interference, the unwanted reception of radio signals. You'll find out how to determine what is at fault (the transmitter or the receiver) and what you can do in either case.

Toroid Pro - Designed by microwave engineers to provide filter, radio,microwave and Ham radio engineers with all relevant information of an inductor and core at his or her finger tips

Grounding and RFI - Described system was designed to provide a high level of lightning protection - there are three levels of defense to guard against let-through. It isn't perfect, but does, however, follow good guidelines and shows measured improvements in RFI reduction.

Amateur Radio RF Safety Calculator - University of Texas Amateur Radio Club RF-Calculator. This is a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations

RF in shack with vertical and longwire antennas - Why a vertical antenna or longwire antenna might require a balun

KØBG's ham radio mobile operator web site - This site is dedicated to mobile amateur radio operators, old and new alike. Whether you are into HF, or VHF operation, I trust the information presented will increase your enjoyment of our great hobby. With safety as a byword, there are articles on amplifiers, antennas, bonding, impedance matching, installing hardware, mobile equipment, noise and RFI abatement, wiring, and much more. I do my best to keep these articles up to date, and easy to follow.

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

Interference Handbook - Interference to home electronic equipment is a frustrating problem; but, fortunately, there are several ways to deal with it. This handbook provides a step-by-step process for eliminating the interference

TVI and BCI Filters - TVI and BCI bandpass and bandstop filters in SMD technique. Schematics and images.

Using ferrites for interference suppression - This tutorial is meant to shed some light on the use of ferrites, and also presents some comparative frequency domain measurements both to illustrate some of the points, and to give designers an idea of what they might expect in using and specifying a ferrite component

The "Woodpecker" Tuning aid - This little gadget is that it allows you to tune up at full peak output power, whilst limiting the average power to a fraction of the peak, thereby protecting the PA from meltdown

Common mode chokes - Excellent article on limiting noise using chockes by Chuck Counselman, W1HIS

Homebew RF chocke - RF Choke to prevent hf currents on the feedline

RFI From Computer Networks - Is your router shutting you down ?

RFI Information Page - This page gives information about Radio Frequency Interference, the unwanted reception of radio signals. You'll find out how to determine what is at fault (the transmitter or the receiver) and what you can do in either case.

RFI problems running RTTY - You may never have an RFI problem when running SSB, but all of a sudden you find RFI creeping into your system when using RTTY. Learn why and how to solve it.

Safety: RF awarness guidelines - Although Amateur Radio is basically a safe activity, in recent years there has been considerable discussion and concern about the possible hazards of electromagnetic radiation (EMR), including both RF energy and power frequency (50-60 Hz) electromagnetic fields. This section summarizes what is now known and offers safety precautions based on the research to date.

Sci.Electronics : RFI/EMI Info - Dealing with Computer generated RFI/EMI by Daniel 9V1ZV

Simple anti-static device - With all the wire you have out, you may run into a problem with static buildup on the antennas. This static may try to make its way into your receiver, causing you major problems and damage that can run into a lot of money.

Telephone Interference - Telephone EMI, questions and answers on how to solve interference problems to phone lines

Television channel 11 interference. - Solving interference from television channel 11 on 144MHz transverters by Chris Cox, NØUK, G4JEC

Television Interference - TVI - VR2XMT article on TVI and how to solve interference problems

The "Woodpecker" Tuning aid - This little gadget is that it allows you to tune up at full peak output power, whilst limiting the average power to a fraction of the peak, thereby protecting the PA from meltdown

The EMI - RFI page - Article on radio frequency interferences, with a long list of common RFI cause, like Plasma TV, Solar panels inverters, fluorescent tube lamps.

Toroid Pro - Designed by microwave engineers to provide filter, radio,microwave and Ham radio engineers with all relevant information of an inductor and core at his or her finger tips

Track down television interference - Nearly half of all reception problems are due to deficiencies or faults in the television receiver, the aerial lead or the aerial. This article will help you to check whether the problem you are having is due to one of these causes.

TVI and BCI Filters - TVI and BCI bandpass and bandstop filters in SMD technique. Schematics and images.

TVi Basics - making filters - TV Interference filters, making TVI filters, coaxial filters to eliminate TV interferences caused by radio frequency

TVI Filter schematic - A simple TVI Filter schematic

TVI filters - These filters are in use by hundreds of VHF weak signal operators and have been proven to be an effective solution for fundamental overload problems.

TVI Filters - Schematic and diagrams for TVI Filters by G4WPW

UHF Reject filter - This filter is a 0.1 dB Tschebychev lowpass with a rejection of 90 dB or better at 430 MHz, and 0.2 dB insertion loss at 72 MHz.

Using ferrites for interference suppression - This tutorial is meant to shed some light on the use of ferrites, and also presents some comparative frequency domain measurements both to illustrate some of the points, and to give designers an idea of what they might expect in using and specifying a ferrite component

VK5BR : Intermodulation - Intermodulation Performance and Measurement of Intermodulation Components by Lloyd Butler VK5BR First published in "Amateur Radio" August 1997

Where Does the Power Go - An Energy Analysis at an Impedance Discontinuity in an RF Transmission Line