frequency interference

Multiband fan dipole antenna - A three-frequency multi-band dipole

Coaxial feeder or RF coax cable - An overview of coax cable often called coaxial feeder or RF cable, used to feed antennas and deliver radio frequency power from one point to another

Helical Antennas - The Helical antenna description, a simple way of obtaining high-gain and a broad band of frequency characteristics

The Versatile Vee Beam - An aerial that you can use on all eight High Frequency amateur bands (80, 40, 30, 20, 17, 15, 12 and 10m) with an antenna tuner, and which gives significant gain on the five bands from 20 m to 10 m

Tuning HF Coaxial Antenna Traps - The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

V25WV Barbuda - DX mobile from Barbuda follow on twitter wd8mgz for frequency schedule time or on ecolink

Hittite Microwave Corporation - Amplifiers, filters, attenuators, mixers, PLL, switches and frequency dividers, signal generators, power detectors, transimpedance amplifiers, variable gain amplifiers and more

LBA Technology - LBA - DTV & RF test systems; AM antennas; RF shielding; RF compliance, safety, interference, intermodulation services; AM detuning, Antenna SWR Analyzers

SSTV Frequency List - Where to look on the Bands for SSTV

VLF Group - Starlab Very low frequency group

VOACAP Online - Online professional-grade high-frequency (3-30 MHz) propagation predictions

Small Antennas for High Frequencies - This is about Small Antenna types and their properties which can help choosing proper antenna for high-frequency wireless communications as: two-way radio, microwave short links, repeaters, radio beacons or wireless telemetry

Frequency adjustment on TS-870 - Adjusting frequency on Kenwood TS-870S

Mods Kenwood TS-870 ACC2 Input - This mod flattens out the ACC2 audio input low frequency response

U.S. VHF Channells - US coast guard frequency list

What's On Short-Wave right now?  ^updated - Find out what station is broadcasting in what language on what frequency. View schedules by frequency, language or station.

JT65-HF - Download JT65-HF Amateur Radio software for reception/transmission of JT65A protocol with an emphasis upon its usage in the High Frequency Amateur Bands.

MicroMUF - MicroMUF is a windows free HF propagation calculator that you can use to estimate the MUF (Maximum Usable Frequency) and LUF (Lowest Usable Frequency) between any two points on the Earth.

Multi-Instrument - Contains a PC sound card based signal generator. It can generate functions, multitones, arbitrary waveforms, burst tones, MLS, DTMF, musical scales, white noise and pink noise, and frequency/amplitude sweep. Fully functional free trial downloadable.

Frequency Response Plotter - Draw static response time of an audio system. Originally intended for loudspeakers tests, is also a great tool for looking at microphone equalisation.

Spectrogram for iPhone - Spectrogram for iPhone displays a live, scrolling display of sound frequency components derived from a 1024 FFT analysis.

Programmable 50 MHz Counter - The frequency counter described here was built up using the "sandwich" construction and uses low cost components

Improved PL Tone encoder - N1HFX project to improve PL tone encoder providing a more stable frequency

20m CW QRP Transceiver - The direct-conversion receiver uses an audio-based automatic gain control, an LC tone filter, and a 100-kHz crystal for frequency alignment. The same VFO is used for transmitting and receiving by DC1YB

Identifying sources of radio frequency interference - This page describes the results of some tests with a portable spectrum analyzer in attempt to identify the sources of RFI around the house. Radio interference was found in a number of unexpected places.