60 lines
3.1 KiB
Plaintext
60 lines
3.1 KiB
Plaintext
>From: die@cpoint.clearpoint.com (David I. Emery)
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>Newsgroups: rec.radio.shortwave,rec.ham-radio,sci.electronics
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>Subject: Monitoring Air Force One Communications - End of an era
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>Keywords: 27000 28000 X-Band Milstar Nationwide Autovon GEP
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>Message-ID: <7230@cpoint.clearpoint.com>
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>Date: 31 Aug 90 06:29:04 GMT
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>Sender: die@cpoint.clearpoint.com
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>Followup-To: rec.radio.shortwave
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>Organization: Clearpoint Research Corp., Hopkinton Mass.
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>Lines: 46
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The new Air Force One, a 747 with tail number 28000, has been
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delivered to the Air Force and is currently conducting tests prior to being used
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to carry the president for the first time.
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It appears that this aircraft will use multichannel X-Band DSCS
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(7-8 Ghz) or millimeter wave (20 and 40 Ghz) Milstar satcom for its
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primary voice/data links to the ground, relegating the 225-400 MHz
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UHF-FM-FDM Autovon GEP circuits and the 415 MHz NBFM "Nationwide"
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circuit to the same low priority, infrequently used, backup role as the
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traditional HF SSB "Mystic Star" channels that are still kept up
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to AF-1 for communication coordination and emergency backup.
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This means that in the next few days a 27 year long era will
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draw to a close for radio hobbiests; it will no longer be possible to
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listen in on much of the telephone traffic (almost all but the secure
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satcom) from the presidents plane as it flies overhead. This marks the
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passing one of the last "in-the-clear" federal communications systems
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carrying genuinely interesting traffic that can be monitored with simple
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equipment; although the UHF-wideband FM GEP Autovon and nbfm Nationwide
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circuits will supposedly still be maintained to the plane and may carry
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occasional traffic, it will likely be very low level, routine, and
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infrequent.
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For many years (from the 60s to the early 80's) the secure
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circuits from the plane were often of such poor quality (1200 baud
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vocoded voice was used for several years using first generation vocoders
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designed in the 60s) that many presidential calls were routed over
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the Autovon and Nationwide channels, and even in the last few years
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quite a few presidential calls have showed up on these clear circuits,
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especially on the Autovon (the "Alpha" and "Bravo") channels. For those
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who enjoyed such things and knew about how the circuits worked there
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was some interesting listening, especially in the early days of the
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systems before the introduction of usable secure satcom for high level
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calls.
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So thus passeth into cryptographic obscurity one of the most
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interesting remaining open federal circuits. Soon the only interesting
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easily received US government signals in the clear will be NOAA weather
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broadcasts, NASA Select TV and Wefax transmissions. I am sure that
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there are those at NSA, IRAC and the White House Office of Telecomunications
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Policy who are saying it's about time this was true.
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--
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David I. Emery Clearpoint Research Corp.
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35 Parkwood Dr, Hopkinton Ma. 01748 +1-508-435-7462
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{m2c,frog,harvard}!crackers!cpoint!die, Internet: die@clearpoint.com
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