Digital Signals FAQ V4.0

Digital Signals FAQ Version: 4.0               +--------------------------+     
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Last Update: May 21, 1996                      |         |     |          |     
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Copyright © 1995,1996 Stan Scalsky             |  |||  ||||| |||||  |||   |     
Copyright © 1995,1996 Mike Chace               | |||||||||||||||||||||||  |     
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                                               | D I G I T A L  R U L E S |     
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Changes made for Version 4.0
   * New modes info, 36-50, 4+4, 1200-FSK, NATO, VFT, PSK and mystery modes
   * New Reordered VHF info, added new FLEX, POCSAG, ERMES, NEC-D3 info
   * New info added for Amateur modes
   * Expanded Alphabet Tables
   * SELCAL info added w/New Table
   * References section updated

Changes made for Version 3.0
   * major reorganization of document
   * added new info/corrected info in modes section
   * added new mystery signals section
   * added new info/corrected system parameters section
   * added new information to the decoder manufacturers section
   * Expanded references section

This Signals FAQ is a collaborative effort, maintained by Stan Scalsky and Mike Chace. Any questions, comments or corrections will gladly be accepted. The authors imply no guarantee on this information and do not claim to be experts or professionals in the field of signal monitoring. All information has been gathered from public domain sources, manufacturers documents, decoder documentation, real time analysis and any radio related publication that cares to write about digital signals. We have tried to research for correctness each mode listed but it must be said that there are a lot of inaccuracies and dis- information present in the mainstream press. It is therefore a safe assumption to assume that those inaccuracies could also appear here.

Many thanks to those of you who post logs, information and answer stupid questions in the various forums that cover digital signals - you know who you are.

I would like to solicit material, to be included later, on any other analysis techniques and/or DF techniques the utilities community is currently using.


* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
A word of Caution:  the rules  about listening  to signals not intended for
you  applies  here.  The  contents  of  many  signals  might  be considered
sensitive by  the party  sending and  the reception  of such signals may be
illegal in your country. The authors neither condone or encourage such acts
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *


Section 0 - Introduction
An introduction to Digital Utilities and some thinking behind the better
qualities of the essential tool - the decoder. Worth a scan if you are
considering the purchase of a decoder.
Section 1 - Modes on Shortwave
Read this section for information on all the modes currently documented. All
the synchronous data block, synchronous bit stream, asynchronous bit stream,
and asynchronous data block systems are here.
Section 2 - Modes on VHF
Read this section for information on all the known pager modes and SELCAL
systems, current and obsolete.
Section 3 - Baud Rate Summary Table
This section references the measured baud rate to the system(s) usually found
at the particular speed. A handy reference for pin-pointing the unknowns.
Section 4 - System Parameters Summary Tables
All the essential information that makes up a system is listed here.
Section 5 - What decoders are available
This section gives the specifics on top of the line decoders. Details on the
most well known of the hobbiest and public domain units. If you want
capability, you cant beat a professional unit.
Section 6 - References
A smattering of documents, frequency databases and signal samples used by most
die hard utility hounds. Also listed are important WWW pages and email
addresses of the various manufacturers.

Goto... [Next Section] , [References]

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