Interference
Interference
Related wiki pages: Broadband over Power Lines (BPL) What causes QRN?, Propagation, Bands, Antennas
Interference or noise is the effect of unwanted radio signals in the same frequency that one is listening to or wishes to transmit on. Interference is generally classified as being either man-made or natural.
Man-made
Main article: QRM
Man made interference (also called QRM) is created by man-made electrical devices. Broadband over Power Lines (BPL) is a good example of this. Links to another page of this wiki can be found below.
Natural
Main article: QRN
Natural interference (also called QRN) is created by natural phenomenons. However, the abbreviation (QRN) is ofent used to designate any source of noise. QRN can be terristrial or cosmic.
Terrestrial sources include lightning, which is generally worse in summer on the lower HF bands, due to increased numbers of storms. Rain and snow storms can also produce significant interference.
Cosmic interference results from the emission of high energy radio waves from stars including our own sun. The sun has by far the greatest effect in this category, due to its proximity to Earth.
Electronic Theory | |
Physical quantities | Current * Gain * Impedance * Power * Q of a circuit * Radiated Power Measurement * Reactance* Resistivity * Resonance * Voltage |
Components | Baluns * Bipolar-Junction Transistors * Capacitors * Diodes * Inductors* Lasers * Microphones * Resistors * Transformers * Wire |
Circuits | Attenuators * Digital Signal Processing (DSP) * Dummy load * Filters * LC filters * Power Supply Design * Rectifier Circuits |
Design | Amplifier Design * Oscillator Design |
Electromagnetic Waves | Relative power (Decibels) * Harmonics * Interference and BPL |
Propagation and radio wave theory | |
Propagation | Aurora * E-Skip * IPS * Lightning scatter * Meteor scatter * Satellites * Trans-Equatorial Propagation * Tropospheric ducting |
Interference | QRM * QRN |
Theory | Electromagnetic Waves * Frequency Wavelength and Period |