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Difference between revisions of "HF Military Communications"

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* U.S. Air Force Operations
 
* U.S. Air Force Operations
 
* U.S. Navy Operations
 
* U.S. Navy Operations
* U.S. Coast Guard Operations
+
* [[United States Coast Guard]] Operations
 
* Flight status updates
 
* Flight status updates
 
+
* Many military stations, both US and foreign, use [http://www.sigidwiki.com/wiki/Automatic_Link_Establishment_(2G_ALE) ALE] to establish a good communications path before sending traffic.
 
 
==The HF Military Communications Receiver==
 
A receiver for monitoring HF military communications must have the following
 
features:
 
 
 
* Coverage from 100 kHz to 30 MHz
 
* Upper sideband (USB) and lower sideband (LSB) modes
 
* Good stability (doesn't drift off frequency)   
 
* Good selectivity (able to seperate 2 stations that are close to one another in frequency)
 
 
 
 
 
Many receivers and portables marketed as shortwave or world band radios will satisfy 
 
these requirements.  The majority of voice communications use USB, but LSB is
 
certainly possible (the Mexican Army is famous for this); therefore, whatever you
 
select '''must''' have USB and LSB capabilities. The lower band limit of   
 
100 kHz is typical of many HF radios, but most military transmissions occur
 
at 2 MHz and above. Other features such as memory channels and alpha tagging
 
are desirable, but not necessary.  See the [[Utility Monitoring]] section
 
for more information.
 
 
 
; What about digital modes?                                                 
 
The military utilizes numerous digital modes, only a few of which can be decoded
 
by software available to the general public. However, a mode often referred to as
 
Automatic Link Establishment (sometimes also written as MIL STD 188-144A) can easily be decoded.  This software is often used to test the radio path between 2
 
stations, and on occasion, pass simple messages. See the [[ALE]] page for decoding
 
software - including some freeware. 
 
 
 
 
 
==Propagation and Antennas==
 
Your ability to receive HF military communications is affected by signal propagation
 
conditions in the atmosphere.  Many factors affect propagation, including sunspots, solar
 
flares, and the time of day. Frequencies above 10 mhz or so are usable during the
 
local daytime, while frequencies below 10 mhz will be usable at night.
 
If you are a newcomer to this topic, reading a good primer would be a great benefit. Don't
 
get discouraged about all the jargon; whole books and very technical scientific papers have
 
been written on the subject; but it's unnecessary to have a degree to gain a basic understanding.
 
To get you started, please see the [http://www.ae4rv.com/tn/propflash.htm Propagation Primer] 
 
website by Geoffrey Noles AE4RV (requires Flash player).
 
 
 
 
 
Your station is only as good as the antenna you can use. The best antennas for 
 
receiving HF military comms is going to depend largely on what you can put up
 
and what kind of receiver you are using. Generally, something that is relatively broadbanded -
 
such as a random wire or inverted L - will be the best one to get you started. Our [[HF Antennas]]
 
page has a number of possibilities, including some that are already assembled - all you need to do
 
is supply the feedline and proper connectors.
 
 
 
If you live in an urban area, or are plagued with noise problems, consider utilizing
 
a loop antenna. MW DXers have been utilizing loops for their directional capabilities almost since
 
the beginning of the broadcast industy; they are useful for HF listening because they are less
 
sensitive to certain kinds of electrical noise. If you're interested in this topic, please
 
see our [[Loops]] page.
 
 
 
 
 
==How to Find Activity?==
 
The spectrum for HF military communications is very wide.  Unlike VHF/UHF
 
scanning, it's challenging to automatically scan a segment of the band
 
because HF noise will always be present. So, here are some places to start
 
searching for HF military communications:
 
  
  
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* 23200.0 – 23350.0 kHz
 
* 23200.0 – 23350.0 kHz
  
===USAF HF-GCS===
+
 
[[USAF High Frequency Global Communications System]]
+
===Well Known Networks===
 +
*[[COTHEN]]
 +
*[[USAF High Frequency Global Communications System]]
  
  
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The more time passes, the harder it is to hear again. Mailing lists are one of the best
 
The more time passes, the harder it is to hear again. Mailing lists are one of the best
 
ways to keep ahead of what is being heard, as traffic can be passed relatively quickly.  
 
ways to keep ahead of what is being heard, as traffic can be passed relatively quickly.  
The recently established [http://groups.yahoo.com/group/udxf/ Utility DXers Forum]      
+
The [https://groups.io/g/UDXF Utility DXers Forum] is very active and is only one of many such lists; more are available on the [[Utility Monitoring]] page.
is currently highly active and is only one of many such lists; more are available on the  
+
 
[[Utility Monitoring]] page.
+
Also see the links page of the [http://www.udxf.nl/links.html Utility DXers Forum] home page, which has numerous military related links
 +
 
 +
In addition, see these links
 +
* [http://myafn.dodmedia.osd.mil/RadioFrequencies.aspx Armed Forces Network]
 +
** What was once known as the Armed Forces Radio and TV Network (AFRTS)
 +
* [http://mt-milcom.blogspot.com/ Milcom Blog by Larry Van Horn]
  
  
 
===Magazine Logs===
 
===Magazine Logs===
A few magazine publications have columns devoted to HF military logs
+
[http://www.thespectrummonitor.com/index.aspx The Spectrum Monitor] Electronic Magazine is the only remaining hobby level magazine that publishes logs from its subscribers. Most others have gone by the wayside, having been supplanted by many web-based sites - which may or may not have up to date information.
submitted by readers.  This is a great way to discover what other people are
+
 
listening to. These logs will often include multiple entries for the same
+
 
frequency, which means that frequency has been active. However, keep in mind
+
==What Equipment Will I Need to Hear these Stations?==
that, due to publishing constraints, there is often a 60 or 90 day lag between
+
* See our [[The HF Utility Receiver and Accessories]] article for a discussion of this topic.
when the report is received and when it's actually published.
+
 
 +
 
 +
==Digital and Other Modes==
 +
As noted above, many military stations now use [http://www.sigidwiki.com/wiki/Automatic_Link_Establishment_(2G_ALE) ALE] before sending actual traffic. Many times, though, this traffic is sent using modes not available on hobby level decoding software, and/or is heavily encoded or encrypted. See our [[DXing Digital Utilities]] article for a more complete discussion on some of these modes.
  
* [http://www.popularcommunications.com Popular Communications] - Utility Communications Digest
+
[[Category:HF Frequencies in Military]]
* [http://www.monitoringtimes.com Monitoring Times] - Utility World Column
+
[[Category:United States Air Force]]
 +
[[Category:United States Air Force Frequencies]]
 +
[[Category:United States Army]]
 +
[[Category:United States Army Frequencies]]
 +
[[Category:United States Coast Guard]]
 +
[[Category:United States Coast Guard Frequencies]]
 +
[[Category:United States Navy]]
 +
[[Category:United States Navy Frequencies]]

Latest revision as of 18:23, 28 July 2018

HF Military Communications

HF military communications can be found below 30 MHz. Here's a sample of what you can hear:

  • U.S. Air Force Operations
  • U.S. Navy Operations
  • United States Coast Guard Operations
  • Flight status updates
  • Many military stations, both US and foreign, use ALE to establish a good communications path before sending traffic.


Aeronautical Off Route Sub-Bands

These bands have been designated for aircraft usage with a channel spacing of 3 kHz. HF military communications will typically occur in these band segments.

  • 3025.0 – 3155.0 kHz
  • 3800.0 – 3950.0 kHz
  • 4700.0 – 4750.0 kHz
  • 4750.0 – 4850.0 kHz
  • 5450.0 – 5480.0 kHz
  • 5680.0 – 5730.0 kHz
  • 6685.0 – 6765.0 kHz
  • 8965.0 – 9040.0 kHz
  • 11175.0 – 11275.0 kHz
  • 13200.0 – 13260.0 kHz
  • 15010.0 – 15100.0 kHz
  • 17970.0 – 18030.0 kHz
  • 23200.0 – 23350.0 kHz


Well Known Networks


Other Sources of Military Related Activity

Unlike broadcast stations, knowing when a military station is going to be on the air is a game of patience; thus, any reporting of activity is very time sensitive. The more time passes, the harder it is to hear again. Mailing lists are one of the best ways to keep ahead of what is being heard, as traffic can be passed relatively quickly. The Utility DXers Forum is very active and is only one of many such lists; more are available on the Utility Monitoring page.

Also see the links page of the Utility DXers Forum home page, which has numerous military related links

In addition, see these links


Magazine Logs

The Spectrum Monitor Electronic Magazine is the only remaining hobby level magazine that publishes logs from its subscribers. Most others have gone by the wayside, having been supplanted by many web-based sites - which may or may not have up to date information.


What Equipment Will I Need to Hear these Stations?


Digital and Other Modes

As noted above, many military stations now use ALE before sending actual traffic. Many times, though, this traffic is sent using modes not available on hobby level decoding software, and/or is heavily encoded or encrypted. See our DXing Digital Utilities article for a more complete discussion on some of these modes.