HFUnderground - User contributions [en]

NASA

2010-02-08T16:06:06Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
| Notes
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| February 2010
|-
| 5810
| August 2009
| Briefly, co-channel with a broadcaster
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| February 2010
|-
| 9132
| July 2009
|-
| 10780
| October 2009
|-
| 11104
| October 2009
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

[[Category:Utility radio stations]]

NASA

2009-10-27T15:12:05Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
| Notes
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
| August 2009
| Briefly, co-channel with a broadcaster
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| October 2009
|-
| 11104
| October 2009
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-29T02:30:57Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
| Notes
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
| August 2009
| Briefly, co-channel with a broadcaster
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| August 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-29T02:30:26Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
| Notes
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
| August 2009
| (briefly, co-channel with very strong broadcast signal)
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| August 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-29T02:29:36Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
| August 2009 (briefly, co-channel with very strong broadcast signal)
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| August 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-29T01:40:44Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| August 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| August 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-25T03:08:30Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
|-
| 6751
| August 2009
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| July 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| August 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-25T00:56:35Z

RikvanRiel:

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| May 2008
|-
| 5810
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| July 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| July 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

These frequencies are also used by other users of the shortwave spectrum, so take your time to confirm that you are really hearing NASA.

NASA

2009-08-25T00:52:07Z

RikvanRiel: New page: Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between C...

Most of communications NASA does with airplanes and spacecraft happen on VHF, UHF and higher frequencies. However, during every space shuttle launch, there are HF communications between Cape Radio, the Booster Recovery Director and the Solid Rocket Booster (SRB) recovery ships Freedom Star and Liberty Star.

There is a long list of possible frequencies for these communications, but only a few of these have been heard in 2008 and 2009. Those have been marked with a *. Communications are in USB mode, in voice as well as ALE data bursts (automatic link establishment).

{| border="1"
|+ Space Shuttle SRB recovery ship comms
|-
| Frequency
| Last heard
|-
| 2764
|-
| 2836
|-
| 3041
|-
| 3120
|-
| 3187
|-
| 3365
|-
| 4993
|-
| 5011
|-
| 5180
|-
| 5246
|-
| 5711
| March(?) 2009
|-
| 5810
|-
| 6897
|-
| 6937
|-
| 7525
|-
| 7765
|-
| 7833
| July 2009
|-
| 9043
| July 2009
|-
| 9132
| July 2009
|-
| 10780
| July 2009
|-
| 11104
|-
| 11205
|-
| 14973
|-
| 17780
|-
| 20185.6
|-
| 20390
|}

Shortwave Utility Stations

2009-08-25T00:38:55Z

RikvanRiel: /* Aeronautical */

Utility stations presumably serve a useful purpose, for example communication between ship and shore. Many of them only have scheduled broadcasts for a few minutes a day, making them interesting DX targets.

== Marine ==

* [[Northern Canada Coast Guard]]

* [[Maritime Weather Transmissions]]

*[[Maritime Fax Transmissions]]

== Military ==

== Aeronautical ==

* [[FAA Flight Control/SELCALL]]
* [[New York Radio]]
* [[MWARA]]
* [[NASA]]

== Beacons ==
*[[HiFER]]
*[[JG2XA]]
*[[High_Frequency_Beacons]]

== Remote Control and Data ==
*[[Remote Control]]

[[Category: Radio station lists]]

Longwave Broadcast Stations

2007-09-28T14:14:57Z

RikvanRiel:

{|
| kHz || Station || Country || Power (kW) ||
|-
| 153 || Bechar || Algeria || 1,000 ||
|-
| 153 || [http://www.dradio.de/dlf Deutschlandfunk] || Germany || 500 || DRM? ||
|-
| 153 || Bod || Romania || 1,200 ||
|-
| 162 || [http://www.radiofrance.fr/franceinter France Inter] || France || 2,000 ||
|-
| 162 || Agri || Turkey || 1,000 ||
|-
| 171 || [http://www.medi1.com Nador Medi-1] || Morocco || 2,000 ||
|-
| 171 || B'shakovo etc || Russia || 1,200 ||
|-
| 177 || [http://www.dradio.de Deutschland Radio] || Germany || 750 ||
|-
| 180 || Polati || Turkey || 1,200 ||
|-
| 183 || [http://www.europe1.fr Europe 1] || Germany || 2,000 ||
|-
| 189 || Caltanissetta || Italy || 10 ||
|-
| 198 || [http://www.bbc.co.uk Droitwich (BBC)] || United Kingdom || 500 ||
|-
| 207 || Munich DLF || Germany || 500 ||
|-
| 207 || Azilal || Morocco || 800 ||
|-
| 216 || Roumoules RMC || France || 1,400 ||
|-
| 216 || Baku || Azerbaydzhan || 500 ||
|-
| 216 || [http://www.radiomontecarlo.net Radio Monte Carlo] || Monaco || - ||
|-
| 225 || [http://www.polskieradio.pl/jedynka Polish Radio 1] || Poland || - ||
|-
| 234 || [http://www.rtl.fr/ RTL] || Luxembourg || 2,000 ||
|-
| 243 || [http://www.dr.dk D. R. Radio 1] || Denmark || 300 || no longer on the air ||
|-
| 252 || Tipaza || Algeria || 1,500 ||
|-
| 252 || [http://www.atlantic252.com/ Atlantic 252] || Republic of Ireland || 500 ||
|-
| 261 || Burg (R Ropa) || Germany || 200 ||
|-
| 261 || Taldom Moscow || Russia || 2,500 ||
|-
| 270 || Czech Radio || Czech Republic || 1,500 ||
|-
| 279 || Sasnovy || Belarus || 500 ||
|}

Reporting Interference

2007-09-23T18:16:17Z

RikvanRiel: /* References */

Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in their target area.

AM stations are vulnerable to several kinds of interference:
* Consumer and industrial electronics.
* Atmospheric noise, which should not be an issue inside a station's target area.
* Interference by other AM stations, especially at night.
* Interference by the digital IBOC sidebands of other AM stations.

== Electronics and atmospheric noise ==

If you have troube listening to an AM radio station, you could try switching off a few electronic devices in your home to figure out exactly which ones are causing trouble. Common electronic devices that can interfere with AM stations are (old) tube TVs and monitors, compact fluorescent lights (CFLs), microwave ovens, computers and switching power supplies.

FCC rules specify that it is legal for such devices to be sold, but illegal for them to be operated when interfering with radio reception. Buyer beware, your own cell phone charger or halogen lighting system could ruin the reception of your favorite sports or talk radio station.

== Interference by stronger AM radio stations ==

The AM regulations in the Americas provide for several classes of radio stations. Class A stations, also called "clear channel" stations, have a high transmission power day and night. They are supposed to be listenable well up to about 400-700 miles away at night, when their signal can bounce off the ionosphere (so-called skywave propagation).

During the day, AM signals only travel along the surface of the earth. Not only does this mean that the Class A stations cannot get their signal out very far, it also opens up space on the band for daytime stations in those areas where the Class A stations cannot be heard. These daytime stations often switch their transmitter off, or go to really low power, at night. If your local daytime station gets overwhelmed by a Class A station at night, tough luck - the Class A station has priority.

== Interference by IBOC (digital) signals ==

Because AM is sensitive to electronic interference, radio stations are slowly switching to digital transmission modes. In North America that mode is IBOC - the rest of the world uses Digital Radio Mondiale (DRM). DRM and all-digital IBOC fit in the normal bandwidth used by an AM station.

However, IBOC also has a so-called "hybrid mode", in which the digital signal is transmitted together with the analog signal. Normally each station on the AM band has a 10 kHz channel, but as you can see the hybrid IBOC signal is 30 kHz wide, covering the two channels adjacant to the station's frequency.

[[Image:AM_IBOC_Mask10.gif]]

Needless to say, the digital noise can be heard when you try to listen to a radio station on a frequency near the station transmitting DRM. In fact, if your radio has wide filters, a station's digital signal could even add noise to the station's own analog signal!

During the daytime, when AM signals do not travel very far, and you can hear few stations on the band, IBOC should not be a big problem - except for stations adding noise to their own signal.

Hybrid IBOC was supposed to be a daytime only transition mode, allowing people to slowly adopt digital radio without stations losing their listeners with older radios. However, since September 14 2007, stations are allowed to keep IBOC on day and night.

At night time, AM radio signals can travel long distances by skywave. Class A stations are supposed to have a clear skywave signal, while medium sized stations are supposed to have clear reception in their local target area. Unfortunately, IBOC sidebands also travel long distances, adding noise to radio stations on adjacant channels and making some stations annoying or impossible to listen to.

== How to identify an IBOC signal ==

Before trying to identify an IBOC signal, you may want to read this web page describing [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html the IBOC spectrum of AM 620 KMKI].

First, remember that IBOC sidebands are symmetrical around a station's main analog signal. If the interference you are hearing is only present on one side of the "suspect" station's analog signal, it is almost certainly not IBOC. If the digital hash is the same on both sides of the "suspect" station's analog signal and gets strongest when you are about 10 kHz away from the "suspect" station, chances are it is IBOC.

If you have a radio with selectable sideband reception (USB/LSB) and are trying to listen to a station 10 kHz away from a station with IBOC sidebands, you may hear that the IBOC interference is weaker on the sideband towards the interfering station and stronger on the other side. The IBOC station is deliberately keeping the stronger digital signals away from its own audio signal.

== How to complain about interference ==

Complaints should go to the station being interfered with, not the station(s)
causing the interference. There are a few exceptions, however. If you feel
that an IBOC station's own digital emissions have degraded their analog
signal quality, you should let them know. Or, if you have reason to believe
that their IBOC equipment is malfunctioning, you should contact them, but
make sure you're on firm ground before you do so.

Keep in mind that interference complaints are more likely to be taken
seriously if they affect reception in or near protected contours.
You can find out what your local stations are using [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator].

The first question to ask yourself is whether the reception is by skywave or
groundwave. Only the Class A stations on the "clear" channels have protected
skywave service, so complaints about interference to skywave signals will
likely fall on deaf ears unless one of those stations is on the receiving end
of the interference. If in doubt, you can check a station's class using
sites such as fccinfo.com or radio-locator.com. Of course, some of the large
market Class A's have little or no interest in skywave service, WOR being a
prime example. At the other end of the spectrum are stations such as WSM
that still have big skywave audiences, and thus should be more receptive to
interference reports.

== References ==

* [http://topazdesigns.com/iboc/AM-IBOC-Parameters.html AM IBOC parameters]
* [http://topazdesigns.com/ambc/ The Canada/US AM Station Info Lookup Page]
* [http://www.fcc.gov/mb/audio/amclasses.html FCC page on AM Broadcast Classes] and a list of Class A stations.
* [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator]
* [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html The IBOC spectrum of AM 620 KMKI]

Reporting Interference

2007-09-23T18:11:09Z

RikvanRiel: /* References */

Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in their target area.

AM stations are vulnerable to several kinds of interference:
* Consumer and industrial electronics.
* Atmospheric noise, which should not be an issue inside a station's target area.
* Interference by other AM stations, especially at night.
* Interference by the digital IBOC sidebands of other AM stations.

== Electronics and atmospheric noise ==

If you have troube listening to an AM radio station, you could try switching off a few electronic devices in your home to figure out exactly which ones are causing trouble. Common electronic devices that can interfere with AM stations are (old) tube TVs and monitors, compact fluorescent lights (CFLs), microwave ovens, computers and switching power supplies.

FCC rules specify that it is legal for such devices to be sold, but illegal for them to be operated when interfering with radio reception. Buyer beware, your own cell phone charger or halogen lighting system could ruin the reception of your favorite sports or talk radio station.

== Interference by stronger AM radio stations ==

The AM regulations in the Americas provide for several classes of radio stations. Class A stations, also called "clear channel" stations, have a high transmission power day and night. They are supposed to be listenable well up to about 400-700 miles away at night, when their signal can bounce off the ionosphere (so-called skywave propagation).

During the day, AM signals only travel along the surface of the earth. Not only does this mean that the Class A stations cannot get their signal out very far, it also opens up space on the band for daytime stations in those areas where the Class A stations cannot be heard. These daytime stations often switch their transmitter off, or go to really low power, at night. If your local daytime station gets overwhelmed by a Class A station at night, tough luck - the Class A station has priority.

== Interference by IBOC (digital) signals ==

Because AM is sensitive to electronic interference, radio stations are slowly switching to digital transmission modes. In North America that mode is IBOC - the rest of the world uses Digital Radio Mondiale (DRM). DRM and all-digital IBOC fit in the normal bandwidth used by an AM station.

However, IBOC also has a so-called "hybrid mode", in which the digital signal is transmitted together with the analog signal. Normally each station on the AM band has a 10 kHz channel, but as you can see the hybrid IBOC signal is 30 kHz wide, covering the two channels adjacant to the station's frequency.

[[Image:AM_IBOC_Mask10.gif]]

Needless to say, the digital noise can be heard when you try to listen to a radio station on a frequency near the station transmitting DRM. In fact, if your radio has wide filters, a station's digital signal could even add noise to the station's own analog signal!

During the daytime, when AM signals do not travel very far, and you can hear few stations on the band, IBOC should not be a big problem - except for stations adding noise to their own signal.

Hybrid IBOC was supposed to be a daytime only transition mode, allowing people to slowly adopt digital radio without stations losing their listeners with older radios. However, since September 14 2007, stations are allowed to keep IBOC on day and night.

At night time, AM radio signals can travel long distances by skywave. Class A stations are supposed to have a clear skywave signal, while medium sized stations are supposed to have clear reception in their local target area. Unfortunately, IBOC sidebands also travel long distances, adding noise to radio stations on adjacant channels and making some stations annoying or impossible to listen to.

== How to identify an IBOC signal ==

Before trying to identify an IBOC signal, you may want to read this web page describing [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html the IBOC spectrum of AM 620 KMKI].

First, remember that IBOC sidebands are symmetrical around a station's main analog signal. If the interference you are hearing is only present on one side of the "suspect" station's analog signal, it is almost certainly not IBOC. If the digital hash is the same on both sides of the "suspect" station's analog signal and gets strongest when you are about 10 kHz away from the "suspect" station, chances are it is IBOC.

If you have a radio with selectable sideband reception (USB/LSB) and are trying to listen to a station 10 kHz away from a station with IBOC sidebands, you may hear that the IBOC interference is weaker on the sideband towards the interfering station and stronger on the other side. The IBOC station is deliberately keeping the stronger digital signals away from its own audio signal.

== How to complain about interference ==

Complaints should go to the station being interfered with, not the station(s)
causing the interference. There are a few exceptions, however. If you feel
that an IBOC station's own digital emissions have degraded their analog
signal quality, you should let them know. Or, if you have reason to believe
that their IBOC equipment is malfunctioning, you should contact them, but
make sure you're on firm ground before you do so.

Keep in mind that interference complaints are more likely to be taken
seriously if they affect reception in or near protected contours.
You can find out what your local stations are using [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator].

The first question to ask yourself is whether the reception is by skywave or
groundwave. Only the Class A stations on the "clear" channels have protected
skywave service, so complaints about interference to skywave signals will
likely fall on deaf ears unless one of those stations is on the receiving end
of the interference. If in doubt, you can check a station's class using
sites such as fccinfo.com or radio-locator.com. Of course, some of the large
market Class A's have little or no interest in skywave service, WOR being a
prime example. At the other end of the spectrum are stations such as WSM
that still have big skywave audiences, and thus should be more receptive to
interference reports.

== References ==

* [http://topazdesigns.com/iboc/AM-IBOC-Parameters.html AM IBOC parameters]
* [http://www.fcc.gov/mb/audio/amclasses.html FCC page on AM Broadcast Classes] and a list of Class A stations.
* [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator]
* [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html The IBOC spectrum of AM 620 KMKI]

Reporting Interference

2007-09-23T17:34:41Z

RikvanRiel:

Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in their target area.

AM stations are vulnerable to several kinds of interference:
* Consumer and industrial electronics.
* Atmospheric noise, which should not be an issue inside a station's target area.
* Interference by other AM stations, especially at night.
* Interference by the digital IBOC sidebands of other AM stations.

== Electronics and atmospheric noise ==

If you have troube listening to an AM radio station, you could try switching off a few electronic devices in your home to figure out exactly which ones are causing trouble. Common electronic devices that can interfere with AM stations are (old) tube TVs and monitors, compact fluorescent lights (CFLs), microwave ovens, computers and switching power supplies.

FCC rules specify that it is legal for such devices to be sold, but illegal for them to be operated when interfering with radio reception. Buyer beware, your own cell phone charger or halogen lighting system could ruin the reception of your favorite sports or talk radio station.

== Interference by stronger AM radio stations ==

The AM regulations in the Americas provide for several classes of radio stations. Class A stations, also called "clear channel" stations, have a high transmission power day and night. They are supposed to be listenable well up to about 400-700 miles away at night, when their signal can bounce off the ionosphere (so-called skywave propagation).

During the day, AM signals only travel along the surface of the earth. Not only does this mean that the Class A stations cannot get their signal out very far, it also opens up space on the band for daytime stations in those areas where the Class A stations cannot be heard. These daytime stations often switch their transmitter off, or go to really low power, at night. If your local daytime station gets overwhelmed by a Class A station at night, tough luck - the Class A station has priority.

== Interference by IBOC (digital) signals ==

Because AM is sensitive to electronic interference, radio stations are slowly switching to digital transmission modes. In North America that mode is IBOC - the rest of the world uses Digital Radio Mondiale (DRM). DRM and all-digital IBOC fit in the normal bandwidth used by an AM station.

However, IBOC also has a so-called "hybrid mode", in which the digital signal is transmitted together with the analog signal. Normally each station on the AM band has a 10 kHz channel, but as you can see the hybrid IBOC signal is 30 kHz wide, covering the two channels adjacant to the station's frequency.

[[Image:AM_IBOC_Mask10.gif]]

Needless to say, the digital noise can be heard when you try to listen to a radio station on a frequency near the station transmitting DRM. In fact, if your radio has wide filters, a station's digital signal could even add noise to the station's own analog signal!

During the daytime, when AM signals do not travel very far, and you can hear few stations on the band, IBOC should not be a big problem - except for stations adding noise to their own signal.

Hybrid IBOC was supposed to be a daytime only transition mode, allowing people to slowly adopt digital radio without stations losing their listeners with older radios. However, since September 14 2007, stations are allowed to keep IBOC on day and night.

At night time, AM radio signals can travel long distances by skywave. Class A stations are supposed to have a clear skywave signal, while medium sized stations are supposed to have clear reception in their local target area. Unfortunately, IBOC sidebands also travel long distances, adding noise to radio stations on adjacant channels and making some stations annoying or impossible to listen to.

== How to identify an IBOC signal ==

Before trying to identify an IBOC signal, you may want to read this web page describing [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html the IBOC spectrum of AM 620 KMKI].

First, remember that IBOC sidebands are symmetrical around a station's main analog signal. If the interference you are hearing is only present on one side of the "suspect" station's analog signal, it is almost certainly not IBOC. If the digital hash is the same on both sides of the "suspect" station's analog signal and gets strongest when you are about 10 kHz away from the "suspect" station, chances are it is IBOC.

If you have a radio with selectable sideband reception (USB/LSB) and are trying to listen to a station 10 kHz away from a station with IBOC sidebands, you may hear that the IBOC interference is weaker on the sideband towards the interfering station and stronger on the other side. The IBOC station is deliberately keeping the stronger digital signals away from its own audio signal.

== How to complain about interference ==

Complaints should go to the station being interfered with, not the station(s)
causing the interference. There are a few exceptions, however. If you feel
that an IBOC station's own digital emissions have degraded their analog
signal quality, you should let them know. Or, if you have reason to believe
that their IBOC equipment is malfunctioning, you should contact them, but
make sure you're on firm ground before you do so.

Keep in mind that interference complaints are more likely to be taken
seriously if they affect reception in or near protected contours.
You can find out what your local stations are using [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator].

The first question to ask yourself is whether the reception is by skywave or
groundwave. Only the Class A stations on the "clear" channels have protected
skywave service, so complaints about interference to skywave signals will
likely fall on deaf ears unless one of those stations is on the receiving end
of the interference. If in doubt, you can check a station's class using
sites such as fccinfo.com or radio-locator.com. Of course, some of the large
market Class A's have little or no interest in skywave service, WOR being a
prime example. At the other end of the spectrum are stations such as WSM
that still have big skywave audiences, and thus should be more receptive to
interference reports.

== References ==

* [http://topazdesigns.com/iboc/AM-IBOC-Parameters.html AM IBOC parameters]
* [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator]
* [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html The IBOC spectrum of AM 620 KMKI]

Reporting Interference

2007-09-23T17:15:45Z

RikvanRiel: /* Interference by IBOC (digital) signals */

Reporting Interference

2007-09-23T17:08:28Z

RikvanRiel:

Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in their target area.

AM stations are vulnerable to several kinds of interference:
* Consumer and industrial electronics.
* Atmospheric noise, which should not be an issue inside a station's target area.
* Interference by other AM stations, especially at night.
* Interference by the digital IBOC sidebands of other AM stations.

== Electronics and atmospheric noise ==

If you have troube listening to an AM radio station, you could try switching off a few electronic devices in your home to figure out exactly which ones are causing trouble. Common electronic devices that can interfere with AM stations are (old) tube TVs and monitors, compact fluorescent lights (CFLs), microwave ovens, computers and switching power supplies.

FCC rules specify that it is legal for such devices to be sold, but illegal for them to be operated when interfering with radio reception. Buyer beware, your own cell phone charger or halogen lighting system could ruin the reception of your favorite sports or talk radio station.

== Interference by stronger AM radio stations ==

The AM regulations in the Americas provide for several classes of radio stations. Class A stations, also called "clear channel" stations, have a high transmission power day and night. They are supposed to be listenable well up to about 400-700 miles away at night, when their signal can bounce off the ionosphere (so-called skywave propagation).

During the day, AM signals only travel along the surface of the earth. Not only does this mean that the Class A stations cannot get their signal out very far, it also opens up space on the band for daytime stations in those areas where the Class A stations cannot be heard. These daytime stations often switch their transmitter off, or go to really low power, at night. If your local daytime station gets overwhelmed by a Class A station at night, tough luck - the Class A station has priority.

== Interference by IBOC (digital) signals ==

Because AM is sensitive to electronic interference, radio stations are slowly switching to digital transmission modes. In North America that mode is IBOC - the rest of the world uses Digital Radio Mondiale (DRM). DRM and all-digital IBOC fit in the normal bandwidth used by an AM station.

However, IBOC also has a so-called "hybrid mode", in which the digital signal is transmitted together with the analog signal. Normally each station on the AM band has a 10 kHz channel, but as you can see the hybrid IBOC signal is 30 kHz wide, covering the two channels adjacant to the station's frequency.

[[Image:AM_IBOC_Mask10.gif]]

Needless to say, the digital noise can be heard when you try to listen to a radio station on a frequency near the station transmitting DRM. In fact, if your radio has wide filters, a station's digital signal could even add noise to the station's own analog signal!

During the daytime, when AM signals do not travel very far, and you can hear few stations on the band, IBOC should not be a big problem - except for stations adding noise to their own signal. Hybrid IBOC was supposed to be a daytime only transition mode, allowing people to slowly adopt digital radio without stations losing their listeners with older radios.

However, at night time AM radio signals can travel long distances by skywave. Class A stations are supposed to have a clear skywave signal, while medium sized stations are supposed to have clear reception in their local target area. IBOC sidebands add noise to adjacant channels and can make stations annoying or impossible to listen to.

== How to identify an IBOC signal ==

Before trying to identify an IBOC signal, you may want to read this web page describing [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html the IBOC spectrum of AM 620 KMKI].

First, remember that IBOC sidebands are symmetrical around a station's main analog signal. If the interference you are hearing is only present on one side of the "suspect" station's analog signal, it is almost certainly not IBOC. If the digital hash is the same on both sides of the "suspect" station's analog signal and gets strongest when you are about 10 kHz away from the "suspect" station, chances are it is IBOC.

If you have a radio with selectable sideband reception (USB/LSB) and are trying to listen to a station 10 kHz away from a station with IBOC sidebands, you may hear that the IBOC interference is weaker on the sideband towards the interfering station and stronger on the other side. The IBOC station is deliberately keeping the stronger digital signals away from its own audio signal.

== How to complain about interference ==

Complaints should go to the station being interfered with, not the station(s)
causing the interference. There are a few exceptions, however. If you feel
that an IBOC station's own digital emissions have degraded their analog
signal quality, you should let them know. Or, if you have reason to believe
that their IBOC equipment is malfunctioning, you should contact them, but
make sure you're on firm ground before you do so.

Keep in mind that interference complaints are more likely to be taken
seriously if they affect reception in or near protected contours.
You can find out what your local stations are using [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator].

The first question to ask yourself is whether the reception is by skywave or
groundwave. Only the Class A stations on the "clear" channels have protected
skywave service, so complaints about interference to skywave signals will
likely fall on deaf ears unless one of those stations is on the receiving end
of the interference. If in doubt, you can check a station's class using
sites such as fccinfo.com or radio-locator.com. Of course, some of the large
market Class A's have little or no interest in skywave service, WOR being a
prime example. At the other end of the spectrum are stations such as WSM
that still have big skywave audiences, and thus should be more receptive to
interference reports.

File:AM IBOC Mask10.gif

2007-09-23T17:08:06Z

RikvanRiel: AM IBOC spectrum. Liberally taken from http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html, who took it from http://www.broadcast.harris.com/extremedigital/pdf/LinearityPerformance.pdf :)

AM IBOC spectrum. Liberally taken from http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html, who took it from http://www.broadcast.harris.com/extremedigital/pdf/LinearityPerformance.pdf :)

Reporting Interference

2007-09-23T17:06:21Z

RikvanRiel: New page: Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in t...

Just like any other radio station, medium wave (AM) stations need listeners. In order to get those listeners, they need to make sure their signal can be received clearly by everybody in their target area.

AM stations are vulnerable to several kinds of interference:
* Consumer and industrial electronics.
* Atmospheric noise, which should not be an issue inside a station's target area.
* Interference by other AM stations, especially at night.
* Interference by the digital IBOC sidebands of other AM stations.

== Electronics and atmospheric noise ==

If you have troube listening to an AM radio station, you could try switching off a few electronic devices in your home to figure out exactly which ones are causing trouble. Common electronic devices that can interfere with AM stations are (old) tube TVs and monitors, compact fluorescent lights (CFLs), microwave ovens, computers and switching power supplies.

FCC rules specify that it is legal for such devices to be sold, but illegal for them to be operated when interfering with radio reception. Buyer beware, your own cell phone charger or halogen lighting system could ruin the reception of your favorite sports or talk radio station.

== Interference by stronger AM radio stations ==

The AM regulations in the Americas provide for several classes of radio stations. Class A stations, also called "clear channel" stations, have a high transmission power day and night. They are supposed to be listenable well up to about 400-700 miles away at night, when their signal can bounce off the ionosphere (so-called skywave propagation).

During the day, AM signals only travel along the surface of the earth. Not only does this mean that the Class A stations cannot get their signal out very far, it also opens up space on the band for daytime stations in those areas where the Class A stations cannot be heard. These daytime stations often switch their transmitter off, or go to really low power, at night. If your local daytime station gets overwhelmed by a Class A station at night, tough luck - the Class A station has priority.

== Interference by IBOC (digital) signals ==

Because AM is sensitive to electronic interference, radio stations are slowly switching to digital transmission modes. In North America that mode is IBOC - the rest of the world uses Digital Radio Mondiale (DRM). DRM and all-digital IBOC fit in the normal bandwidth used by an AM station.

However, IBOC also has a so-called "hybrid mode", in which the digital signal is transmitted together with the analog signal. Normally each station on the AM band has a 10 kHz channel, but as you can see the hybrid IBOC signal is 30 kHz wide, covering the two channels adjacant to the station's frequency.

[[Image:AM_IBOC_Mak10.gif]]

Needless to say, the digital noise can be heard when you try to listen to a radio station on a frequency near the station transmitting DRM. In fact, if your radio has wide filters, a station's digital signal could even add noise to the station's own analog signal!

During the daytime, when AM signals do not travel very far, and you can hear few stations on the band, IBOC should not be a big problem - except for stations adding noise to their own signal. Hybrid IBOC was supposed to be a daytime only transition mode, allowing people to slowly adopt digital radio without stations losing their listeners with older radios.

However, at night time AM radio signals can travel long distances by skywave. Class A stations are supposed to have a clear skywave signal, while medium sized stations are supposed to have clear reception in their local target area. IBOC sidebands add noise to adjacant channels and can make stations annoying or impossible to listen to.

== How to identify an IBOC signal ==

Before trying to identify an IBOC signal, you may want to read this web page describing [http://www.dallas.net/~jvpoll/rfi/AM620_KMKI/AM620_KMKI_01.html the IBOC spectrum of AM 620 KMKI].

First, remember that IBOC sidebands are symmetrical around a station's main analog signal. If the interference you are hearing is only present on one side of the "suspect" station's analog signal, it is almost certainly not IBOC. If the digital hash is the same on both sides of the "suspect" station's analog signal and gets strongest when you are about 10 kHz away from the "suspect" station, chances are it is IBOC.

If you have a radio with selectable sideband reception (USB/LSB) and are trying to listen to a station 10 kHz away from a station with IBOC sidebands, you may hear that the IBOC interference is weaker on the sideband towards the interfering station and stronger on the other side. The IBOC station is deliberately keeping the stronger digital signals away from its own audio signal.

== How to complain about interference ==

Complaints should go to the station being interfered with, not the station(s)
causing the interference. There are a few exceptions, however. If you feel
that an IBOC station's own digital emissions have degraded their analog
signal quality, you should let them know. Or, if you have reason to believe
that their IBOC equipment is malfunctioning, you should contact them, but
make sure you're on firm ground before you do so.

Keep in mind that interference complaints are more likely to be taken
seriously if they affect reception in or near protected contours.
You can find out what your local stations are using [http://www.v-soft.com/ZipSignal/zip_answer.asp V-Soft's zip code radio locator].

The first question to ask yourself is whether the reception is by skywave or
groundwave. Only the Class A stations on the "clear" channels have protected
skywave service, so complaints about interference to skywave signals will
likely fall on deaf ears unless one of those stations is on the receiving end
of the interference. If in doubt, you can check a station's class using
sites such as fccinfo.com or radio-locator.com. Of course, some of the large
market Class A's have little or no interest in skywave service, WOR being a
prime example. At the other end of the spectrum are stations such as WSM
that still have big skywave audiences, and thus should be more receptive to
interference reports.

Mediumwave Broadcast Stations

2007-09-23T16:10:53Z

RikvanRiel: New page: Everything related to medium wave and long wave broadcast stations goes here. * Reporting Interference one of the top priorities for radio stations is being heard. Let them know how ...

Everything related to medium wave and long wave broadcast stations goes here.

* [[Reporting Interference]] one of the top priorities for radio stations is being heard. Let them know how their signal is going through.

Main Page

2007-09-23T15:26:57Z

RikvanRiel:

Welcome to HFUnderground.com. This site is dedicated to documenting oddities on shortwave, including pirate radio and numbers stations.

Everyone who is a radio enthusiast is encouraged to add information to the site. Just become a registered user, and you can start to contribute!

*[[Pirate radio stations]]
*[[Spy numbers stations]]
*[[Shortwave Broadcast Stations]]
*[[Shortwave Utility Stations]]
*[[Mediumwave Broadcast Stations]]
*[[Miscellaneous]]
*[[Technical Topics]]

Main Page

2007-09-23T15:26:05Z

RikvanRiel:

Welcome to HFUnderground.com. This site is dedicated to documenting oddities on shortwave, including pirate radio and numbers stations.

Everyone who is a radio enthusiast is encouraged to add information to the site. Just become a registered user, and you can start to contribute!

*[[Broadcast stations]] on shortwave, medium wave and long wave.
*[[Pirate radio stations]]
*[[Spy numbers stations]]
*[[Shortwave Broadcast Stations]]
*[[Shortwave Utility Stations]]
*[[Miscellaneous]]
*[[Technical Topics]]

Northern Canada Coast Guard

2007-09-15T21:00:46Z

RikvanRiel: New page: Like many others around the world, the coast guard stations in Northern Canada have regularly scheduled broadcasts with forecasts of the weather, shipping conditions and ice coverage. The...

Like many others around the world, the coast guard stations in Northern Canada have regularly scheduled broadcasts with forecasts of the weather, shipping conditions and ice coverage. These broadcasts are mostly done on lower HF frequencies, which give best reception in winter. However, Canada's northern coast is completely frozen in winter, so these coast guard transmissions are only done in summer (May - October), making them challenging DX targets.

== USB Voice ==

{|
| Time (UTC) || Station || Frequencies ||
|-
| 0110 || Coral Harbour, NU || 2514, 6513 ||
|-
| 0115 || Inuvik, NWT || 5803 ||
|-
| 0115 || Hay River, NWT || 4363 ||
|-
| 0235 || Cambridge Bay, NWT || 2558, 4363 ||
|-
| 0235 || Inuvik, NWT || 6218.6 ||
|-
| 1240 || Resolute, NU || 2582, 4363 ||
|-
| 1315 || Inuvik, NWT || 5803 ||
|-
| 1315 || Hay River, NWT || 4363 ||
|-
| 1320 || Coral Harbour, NU || 2514, 6513 ||
|-
| 1340 || Iqaluit, NU || 2582, 4363 ||
|-
| 1340 || Killinek, NU || 2514 ||
|-
| 1435 || Cambridge Bay, NWT || 2558, 4363 ||
|-
| 1435 || Inuvik, NWT || 6218.6 ||
|-
| 1705 || Iqaluit, NU || 2582, 4363 ||
|-
| 1705 || Killinek, NU || 2514 ||
|-
| 1710 (1701?) || Resolute, NU || 2582, 4363 ||
|-
| 2235 || Iqaluit, NU || 2582, 4363 ||
|-
| 2235 || Killinek, NU || 2514 ||
|-
| 2310 || Resolute, NU || 2582, 4363 ||
|}

Shortwave Utility Stations

2007-09-15T20:42:25Z

RikvanRiel: /* Marine */

Shortwave Utility Stations

2007-09-15T20:41:54Z

RikvanRiel: New page: Utility stations presumably serve a useful purpose, for example communication between ship and shore. Many of them only have scheduled broadcasts for a few minutes a day, making them inte...