These broadcast are commonly heard on HF-GCS primary frequencies plus 11244.0 kHz. Please note that not all HF-GCS published frequencies are active for every EAM broadcast time slot listed below. Also some of the activity listed below is not on HF-GCS published frequencies, but on other selected discrete frequencies.
For an in-depth discussion on what an EAM is, see the utility information file on the MT website What is an EAM.
There was an apparent major change to the restoral schedule noted below as of 1 Oct 2004 (beginning of the new U.S. Government fiscal year).
H+00 HF-GCS Offutt AFB, Nebraska
H+03 HF-GCS Offutt AFB, Nebraska
H+06* USN E-6 TACAMO LANT aircraft (6697/11244/13155)
H+07 USN E-6 TACAMO LANT aircraft (6697/13155)
H+10* USN E-6 TACAMO LANT aircraft (6697/11244/13155)
H+12 HF-GCS Andrews AFB, Maryland
H+20 USN E-6 TACAMO PAC aircraft (6697/13155)
H+21* HF-GCS Offutt AFB, Nebraska
H+25 HF-GCS Offutt AFB, Nebraska
H+31 HF-GCS Offutt AFB, Nebraska
H+33 HF-GCS Offutt AFB, Nebraska
H+35* HF-GCS McClellan, California (11244)
H+37* USN E-6 TACAMO LANT aircraft (6697/13155)
H+39 HF-GCS Offutt AFB, Nebraska
H+40* USN E-6 TACAMO LANT aircraft (6697/13155)
H+50 USN E-6 TACAMO PAC aircraft (6697/13155)
H+53 HF-GCS Offutt AFB, Nebraska
H+59 HF-GCS Andrews AFB, Maryland
Current as of 24 June 2004
H+00 HF-GCS Offutt AFB, Nebraska
H+05 HF-GCS Andersen AB, Guam
HF-GCS Croughton AB, United Kingdom
H+07 USN E-6 TACAMO LANT aircraft (6697.0/13155.0 kHz)
H+08 USN E-6 TACAMO aircraft HF-GCS six character EAMs "FOR..."
H+09 HF-GCS McClellan, California
H+14 USN E-6 TACAMO PAC aircraft (6697.0/13155.0 kHz)
H+20 HF-GCS Salinas, Puerto Rico
H+21 New: HF-GCS Offutt AFB, Nebraska
Old: HF-GCS Elmendorf AFB, Alaska
H+25 USSTRATCOM Looking Glass mission aircraft
H+29 HF-GCS Sigonella Naval Station, Sicily
H+30 HF-GCS Andrews AFB, Maryland
H+34 HF-GCS Hickam AFB, Hawaii
H+35 HF-GCS Croughton AB, United Kingdom
H+37 USN E-6 TACAMO LANT aircraft (6697.0/13155.0 kHz)
H+38 USN E-6 TACAMO aircraft HF-GCS six character EAMs "FOR..."
H+40 HF-GCS Elmendorf AFB, Alaska
H+44 USN E-6 TACAMO PAC aircraft (6697.0/13155.0 kHz)
H+46 Unknown station
H+49 HF-GCS McClellan, California
H+50 HF-GCS Lajes AB, Azores
H+55 USSTRATCOM Looking Glass mission aircraft
H+59 HF-GCS Sigonella Naval Station, Sicily
Earlier examples of this broadcast schedule can be seen in the various 1980s editions of the Grove Shortwave Directories (usually on page 5 for those that still have them) - Those minute stamps were also used for the then common "standing by for traffic" calls heard from the various GIANT TALK ground stations operating under their pre-92 daily changing callsign aliases.]
The FOXTROT (SKYKING) messages are also common, or at least they used to be. You should generally hear more than two over any 24 hour period. Of interest, the preface to the FOXTROT broadcasts that would name the echoing ground stations have not been heard (here) since maybe sometime in April 2003 (around the end of major combat in Iraq.) I've heard no instance of a request to DIEGO GARCIA or THULE or anyone else since around that time, just the occasional FOXTROT broadcast from ANDREWS or whoever. They dropped the DECENT, ENLIST, FAIRLY, EYESTRAIN, DEFROSTER
echo requests sometime around Sept 2001 (maybe) to be replaced with plaintext station names (THULE, DIEGO GARCIA, CYPRUS FLIGHT WATCH) after 9/11, and now since around April 2003 maybe nothing.
Busiest frequencies are 8992.0 ("Eight-Niner") and 11175.0 ("Triple-1"), which most stations guard around the clock. The others operate on a schedule which changes twice yearly, on the first of April and October. The upper sideband (USB) mode is used on all HF-GCS frequencies listed above.
Note: The data signal you will on 9025.0 kHz is ALE which is a computerized system that simplifies HF operation (see section below). Older frequency circulated on the internet continue to list 8968.0 and 17976.0 kHz, but these were removed from HF-GCS service several years ago.
Thanks to my friend Jeff Haverlah for the information in this blog message.