Note: Echo-Fox is no longer in service; it is reported to have been shut down in 1996.
The following discussion of the Echo-Fox network was posted by Dave Emery on June 7, 1993 on the rec.radio.info newsgroup:
The UHF NBFM system Harold Peach mentioned (on 415.7/407.85) is code named "Echo Foxtrot", or "Nationwide" (the later name distinguishes it from the "Washington Area" system used for communications with White House limos and staff cars). It provides full duplex clear voice coverage over most of the continental US to VIP aircraft in flight (SAM aircraft - Special Air Missions - which fly out of Andrews AFB). It links them to a console at the White House Switchboard ("Crown") in the Old Executive Office building basement from which phone patch connections can be made to telephones at the White House, on the commercial POTS/DDD network, various other federal telephone systems, and occasionally the DSN (Defense Switched Network - formally Autovon). (E/F is not an Autovon system or just intended for Autovon patch use).
The system is operated by the White House Communications Agency (WHCA), and AT&T. Ground sites (there are about 30 of them) for the E/F system are located on AT&T microwave towers throughout the US and are connected by leased lines to a tech control console ("Crown Control") that is part of the White House Switchboard ("Crown" or "Signal"). Each individual site can be separately keyed from the console and patched into a call, thus the system is capable of handling several calls at once although the aircraft involved have to be far enough apart not to interfere with one another.
The E/F system is completely manual at both ends, call setup and ground site selection is done by operators. On the ground the operators are WHCA/White House switchboard operators, on the aircraft they are CSO (Communication System Officers) who are military NCO's (tech sergeants mostly).
The E/F system is in-the-clear UHF NBFM full duplex voice. The aircraft often push-to-talk keys its transmitter, so it only transmits when the party on board is talking. The ground site usually transmits continuously for the duration of the call.
The system has been recently used with STU-III's for security, but apparently not too successfully. There have been occasional attempts in the past to use other kinds of secure voice but most calls are still in the clear. Recent White House staff people who use the system have been made aware that listening to it is quite popular amoung scanner hobbiests and have been fairly careful about what they say, but when the system was first installed in the late 60's and early 70's there were some very interesting conversations on it.
E/F antennas on AT&T towers are small and not very conspicuous but they can be recognized if one knows what they look like. They are always mounted at the top of the tower near the Hogg horns. There are usually three antennas, two small ground planes and a short vertical pole mounted above them and three or four feet apart. Air Force One mostly uses the E/F system for actual phone connections when it is out of range of other systems or there is extremely heavy traffic on them (but it always maintains contact via E/F when in range of a ground site as backup anyway), and has in the past sometimes used E/F as a communications order wire to set up calls on the other systems. The Bush conversation with Senator Byrd referred to in the summer 1992 Washington Post article (reproduced and discussed extensively in these newsgroups) about scanner listeners tuning in to the President was one of the relatively rare recent presidential calls on this system (the call took place in August 1990). That call was probably put on E/F due to very heavy traffic on the other lines.
The radio transceiver used in the SAM aircraft was a modified Motorola Mitrek unit.
Echo-Fox antenna cluster atop the tower at the former AT&T Long Lines Regional Center, CLLI code NRWYILNO
Click on image to view a larger version.
Image courtesy of Tim Tyler; photographed May 25, 2002.
|Arkansas||Memphis Junction||Long Lines||ARTNVACKT20|
|California||Mount Wilson||Pacific Tel. & Tel.||ARTNVACKT20|
|California||Stockton||Pacific Tel. & Tel.||ARTNVACKT20|
|California||Turquoise Junction||Pacific Tel. & Tel.||WASHDCDTW20|
|Colorado||Prospect Valley||Long Lines||ARTNVACKT20|
|Florida||Daytona Beach||Southern Bell Tel. & Tel.||ARTNVACKT20|
|Florida||Perrine||Southern Bell Tel. & Tel.||WASHDCDTW20|
|Idaho||Boise Junction||Long Lines||ARTNVACKT20|
|Iowa||Red Oak||Long Lines||ARTNVACKT20|
|Louisiana||Alexandria||South Central Bell||WASHDCDTW20|
|Maine||Portland||New England Tel. & Tel.||WASHDCDTW20|
|Montana||Helena Junction||Long Lines||ARTNVACKT20|
|Montana||Miles City||Mountain Bell||WASHDCDTW20|
|New Mexico||Clines Corner||Long Lines||ARTNVACKT20|
|Nevada||Winnemucca||Bell Telephone of Nevada||WASHDCDTW20|
|New York||New York City||Long Lines||ARTNVACKT20|
|North Carolina||Westover||Long Lines||ARTNVACKT20|
|Oregon||Mount Baldy||Pacific Northwest Bell||WASHDCDTW20|
|South Carolina||Charleston||Southern Bell Tel. & Tel.||WASHDCDTW20|
|South Dakota||Chamberlain||Northwestern Bell||ARTNVACKT20|
|Texas||Amarillo Junction||Long Lines||WASHDCDTW20|
|Utah||Crescent Junction||Long Lines||WASHDCDTW20|
|Washington||Seattle No. 5||Pacific Northwest Bell||ARTNVACKT20|
|Washington||Spokane||Pacific Northwest Bell||WASHDCDTW20|
|Wyoming||Rock Springs||Mountain Bell||WASHDCDTW20|
Adapted from Bell System Practice 406-116-100, Issue 2, March 1973, pp. 6-7, table A
In addition to the above locations, the AT&T Long Lines microwave main station on Jackie Jones Mountain, near Stony Point and West Haverstraw, New York, was an Echo-Fox site for an as-yet-undetermined period.
This green-shaded area on this map shows the estimated coverage of the Echo-Fox stations listed in the table above (indicated by black dots), assuming a 200-mile range for each transmitter:
Updated on January 12, 2006 at 20:21 by Albert LaFrance