Difference between revisions of "DXing Above 30 Mhz"
From The RadioReference Wiki
(→Maps: updated links and put in alphabetical order) |
m |
||
| (20 intermediate revisions by the same user not shown) | |||
| Line 5: | Line 5: | ||
VHF, UHF and even 800 MHz and higher can be impacted quite significantly by these ducting events. One good example of very high frequencies being impacted is the anomalous propagation that plague the Doppler weather radar (WSR-88D) during the most extreme tropospheric ducting episodes. | VHF, UHF and even 800 MHz and higher can be impacted quite significantly by these ducting events. One good example of very high frequencies being impacted is the anomalous propagation that plague the Doppler weather radar (WSR-88D) during the most extreme tropospheric ducting episodes. | ||
| − | Hams (and folks involved in TV/FM DXing) have been studying this for years. Many of these phenomenon have been cataloged, but not are all well understood. If you are interested in a description of how a VHF signal (or above) can travel, take a look at this [http://en.wikipedia.org/wiki/TV/FM_DX article] on the WikiPedia site. Keep in mind that FM and TV broadcasts, as well as ham frequencies, are found above 30 mhz. Techniques used in TV, FM and | + | Hams (and folks involved in TV/FM DXing) have been studying this for years. Many of these phenomenon have been cataloged, but not are all well understood. If you are interested in a description of how a VHF signal (or above) can travel, take a look at this [http://en.wikipedia.org/wiki/TV/FM_DX article] on the WikiPedia site. Keep in mind that FM and TV broadcasts, as well as ham frequencies, are found above 30 mhz. Techniques used in TV, FM and 144/220/432 Mhz DXing are applicable to DXing in the scanner bands. |
The links below are not intended to be exhaustive, but rather be a starting point for getting more information. Additional links with descriptions and maps are always welcome. | The links below are not intended to be exhaustive, but rather be a starting point for getting more information. Additional links with descriptions and maps are always welcome. | ||
The RR forum for discussing VHF/UHF skip can be found [http://forums.radioreference.com/skip-tropospheric-ducting-forum here] | The RR forum for discussing VHF/UHF skip can be found [http://forums.radioreference.com/skip-tropospheric-ducting-forum here] | ||
| + | |||
| + | ==Applications and Databases== | ||
| + | ; Applications | ||
| + | * [https://www.df8ry.de/htmlen/csvub/%F0%9F%92%BEdownload.htm CSVUserlist Browser] | ||
| + | * [http://www.freqmgrsuite.com/ Frequency Manager Suite] | ||
| + | |||
| + | ; Databases | ||
| + | * [https://www.fcc.gov/media/radio/radio-lists Broadcast AM and FM Radio Reports and Lists] | ||
| + | * [https://www.fcc.gov/media/radio/fm-query#block-menu-block-4 FCC FM Query Broadcast Station Search] | ||
| + | * [https://www.fcc.gov/media/television/tv-query FCC TV Query Broadcast Station Search] | ||
| + | * [https://www.fmlist.org/ul_login.php?sprache=en FMList] | ||
| + | * [https://fmscan.org/index.php?la=en FMScan] | ||
| + | * [http://lpfmdatabase.weebly.com/ LPFM Database] | ||
| + | |||
| + | ==Equipment== | ||
| + | * [https://tinyurl.com/y7eellwj Antennas Direct] | ||
| + | * [https://fmradiodx.wordpress.com/sections/radio-reviews/ FM Radio DX Radio Reviews] | ||
| + | * [http://www.fmtunerinfo.com/ FM Tuner Information Center] | ||
| + | * [[Live Tunable Receivers]] | ||
| + | * [https://www.ccrane.com/item/ant_fm_fmr2/101106/fm_reflect-2_dipole_antenna FM Reflect 2 Dipole Antenna] C Crane Co. | ||
| + | * [[Software Defined Radios]] | ||
==Maps== | ==Maps== | ||
* [https://www.dxmaps.com/spots/map.php DXMaps] | * [https://www.dxmaps.com/spots/map.php DXMaps] | ||
| − | |||
| − | |||
* [https://www.radio-locator.com/cgi-bin/finder?page=Y Radio Station Finder] | * [https://www.radio-locator.com/cgi-bin/finder?page=Y Radio Station Finder] | ||
* [http://tropo.f5len.org Tropospheric Propagation Forecast] | * [http://tropo.f5len.org Tropospheric Propagation Forecast] | ||
* [http://aprs.mennolink.org/ VHF Propagation Map] | * [http://aprs.mennolink.org/ VHF Propagation Map] | ||
* [http://www.dxinfocentre.com/tropo.html William Hepburn's Worldwide Tropospheric Ducting Forecasts] | * [http://www.dxinfocentre.com/tropo.html William Hepburn's Worldwide Tropospheric Ducting Forecasts] | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
==Other Propagation Links== | ==Other Propagation Links== | ||
| − | + | * [http://ac6v.com/propagation.php AC6V Propagation Links] | |
| − | * [http://ac6v.com/propagation. | + | * [https://www.eham.net/propagation EHam Propagation Links] |
| − | * [ | ||
| − | |||
| − | |||
| − | |||
* [[SNOTEL]] - indicator of VHF Low Band Skip | * [[SNOTEL]] - indicator of VHF Low Band Skip | ||
| + | |||
| + | ==Technical Articles== | ||
| + | * [http://www.kg0vl.com/?page_id=5 KG0VL VHF Aurora Radio Research] | ||
==TV/FM DX Links== | ==TV/FM DX Links== | ||
| − | * | + | * [https://www.dxcentralonline.com/ DX Central] |
| − | * [https://www. | + | * [https://www.radioworld.com/news-and-business/fcc-tweaks-lpfm-technical-rules FCC Tweaks LPFM Technical Rules] |
| − | * [https:// | + | * [https://fmradiodx.wordpress.com/ FM Radio DX] |
| − | * [ | + | * [https://band2dx.webs.com/ Long Distance FM Reception from Paul Hogan - Ireland] |
| − | * [http:// | + | * [http://dxworld.com/tvfmlog.html TV FM Skip log] |
| − | * [http://www. | + | * [http://www.wtfda.org/ Worldwide TV/FM DX Association] |
| − | * [http://www. | + | * [http://www.anarc.org/wtfda/propagation.htm WTFDA Propagation Page] old but still lots of useful information. Written by well known author and DXLD owner Glenn Hauser |
| − | + | ==Mailing Lists/Facebook== | |
| − | * [http:// | + | * [http://mailman.qth.net/mailman/listinfo/amfmtvdx AMFMTVDX] qth.net |
| − | * [ | + | * [http://groups.yahoo.com/group/dx-tv/ DX-TV] Yahoo group |
| − | * [ | + | * [https://groups.io/g/odxa Ontario DX Association] groups.io |
| + | * [https://www.facebook.com/groups/WTFDA WTFDA Facebook page] | ||
| + | * [https://groups.google.com/forum/#!forum/wtfda WTFDA on Google Groups] | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
[[Category:Propagation Links]] | [[Category:Propagation Links]] | ||
[[Category:Broadcasting]] | [[Category:Broadcasting]] | ||
Revision as of 08:48, 25 May 2020
Talk to most people about how far a VHF signal (above 30 Mhz) will travel, and most times, the answer will be 'line of sight'. However, as there sometimes is in nature, there's exceptions to the rule. Many phenomenon can cause a VHF and UHF signal to travel hundreds of miles or more. Events such as a stalled weather front to a meteor shower or even the solar wind can change things in the atmosphere and make a signal travel much further than normal.
The most common type of tropospheric ducting to impact scanner hobbyists and amateur radio operators results from a low-level temperature inversion. A low-level temperature inversion is a phenomenon in which the temperature in the lower portion of the atmosphere, near the earth's surface, is considerably cooler than a layer farther up in the atmosphere. This causes signals to be refracted thus resulting in a tunneling or ducting of the signals. Low-level temperature inversions can occur any time of the year but are often most dramatic (producing the most significant tropospheric ducting events) during the summer months. They are most often associated with surface high pressure which results in light near-surface winds allowing for radiative cooling affect. These events also commonly coincide with fog.
VHF, UHF and even 800 MHz and higher can be impacted quite significantly by these ducting events. One good example of very high frequencies being impacted is the anomalous propagation that plague the Doppler weather radar (WSR-88D) during the most extreme tropospheric ducting episodes.
Hams (and folks involved in TV/FM DXing) have been studying this for years. Many of these phenomenon have been cataloged, but not are all well understood. If you are interested in a description of how a VHF signal (or above) can travel, take a look at this article on the WikiPedia site. Keep in mind that FM and TV broadcasts, as well as ham frequencies, are found above 30 mhz. Techniques used in TV, FM and 144/220/432 Mhz DXing are applicable to DXing in the scanner bands.
The links below are not intended to be exhaustive, but rather be a starting point for getting more information. Additional links with descriptions and maps are always welcome.
The RR forum for discussing VHF/UHF skip can be found here
Contents
Applications and Databases
- Applications
- Databases
- Broadcast AM and FM Radio Reports and Lists
- FCC FM Query Broadcast Station Search
- FCC TV Query Broadcast Station Search
- FMList
- FMScan
- LPFM Database
Equipment
- Antennas Direct
- FM Radio DX Radio Reviews
- FM Tuner Information Center
- Live Tunable Receivers
- FM Reflect 2 Dipole Antenna C Crane Co.
- Software Defined Radios
Maps
- DXMaps
- Radio Station Finder
- Tropospheric Propagation Forecast
- VHF Propagation Map
- William Hepburn's Worldwide Tropospheric Ducting Forecasts
Other Propagation Links
- AC6V Propagation Links
- EHam Propagation Links
- SNOTEL - indicator of VHF Low Band Skip
Technical Articles
TV/FM DX Links
- DX Central
- FCC Tweaks LPFM Technical Rules
- FM Radio DX
- Long Distance FM Reception from Paul Hogan - Ireland
- TV FM Skip log
- Worldwide TV/FM DX Association
- WTFDA Propagation Page old but still lots of useful information. Written by well known author and DXLD owner Glenn Hauser
Mailing Lists/Facebook
- AMFMTVDX qth.net
- DX-TV Yahoo group
- Ontario DX Association groups.io
- WTFDA Facebook page
- WTFDA on Google Groups