QRN: Difference between revisions
Jump to navigation
Jump to search
(New page: QRN is "natural interference", as opposed to QRM - "man-made interference". QRN is higher on the long wavelength bands (160, 80, 40), especially at night. What causes QRN) |
(internal link) |
||
| (5 intermediate revisions by 4 users not shown) | |||
| Line 1: | Line 1: | ||
QRN | Strictly speaking QRN means "noise from natural sources" as opposed to [[QRM]] which means "man-made noise". The abbreviation QRN is oftern used in in general terms to mean any noise that [[interference|interferes]] with propagation or reception of transmissions. | ||
QRN is higher on the long wavelength bands (160, 80, 40), especially at night. | QRN is higher on the long wavelength bands (160, 80, 40), especially at night. | ||
== What causes QRN? == | |||
# '''Atmospheric noise'''. This originates in the atmosphere. Lightning creates RF noise over a wide range of frequencies (usually between 100 kHz to 20 MHz) that affects radio transmissions over hundreds of km. Auroral discharges over polar regions generally create noise at lower frequencies (below 0.1 MHz). | |||
# '''Geological activity'''. Increased RF noise has been recorded as a precursor to earthquakes, and near erupting volcanoes | |||
# '''Cosmic noise'''. This comes from a source outside the Earth's atmosphere. The sun produces noise that reaches a maximum at 11 year intervals (the so-called solar or [[Sunspot Cycle | sunspot]] cycle). The planet Jupiter produces large amounts of RF noise in the 16 to 24 MHz range. Stars and galaxies also contribute to cosmic noise. | |||
# '''[http://www.w8pgw.org/node/95 Snow Static]''' yes, snow static! The link provides some detail about this unusual phenomenon | |||
== See also == | |||
* [[Propagation]] | |||
* [[BPL]] | |||
==External links== | |||
* [http://web.archive.org/web/20050924150424/www.arrl.org/tis/info/HTML/rfi-noise/ ARRL noise identification site] | |||
{{propagation}} | |||
Latest revision as of 21:03, 19 November 2010
Strictly speaking QRN means "noise from natural sources" as opposed to QRM which means "man-made noise". The abbreviation QRN is oftern used in in general terms to mean any noise that interferes with propagation or reception of transmissions.
QRN is higher on the long wavelength bands (160, 80, 40), especially at night.
What causes QRN?
- Atmospheric noise. This originates in the atmosphere. Lightning creates RF noise over a wide range of frequencies (usually between 100 kHz to 20 MHz) that affects radio transmissions over hundreds of km. Auroral discharges over polar regions generally create noise at lower frequencies (below 0.1 MHz).
- Geological activity. Increased RF noise has been recorded as a precursor to earthquakes, and near erupting volcanoes
- Cosmic noise. This comes from a source outside the Earth's atmosphere. The sun produces noise that reaches a maximum at 11 year intervals (the so-called solar or sunspot cycle). The planet Jupiter produces large amounts of RF noise in the 16 to 24 MHz range. Stars and galaxies also contribute to cosmic noise.
- Snow Static yes, snow static! The link provides some detail about this unusual phenomenon
See also
External links
| 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 |