From 3d44ae89dfff7560b1d314a249e811a9a14ed185 Mon Sep 17 00:00:00 2001 From: Joe Taylor Date: Sat, 6 Aug 2016 14:30:33 +0000 Subject: [PATCH] Added description of MSK144 Sh messages. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7010 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 --- v1.7_Features.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/v1.7_Features.txt b/v1.7_Features.txt index db15dff87..a0f846649 100644 --- a/v1.7_Features.txt +++ b/v1.7_Features.txt @@ -38,6 +38,17 @@ repeated without gaps for the duration of a transmission cycle. For most purposes we recommend a T/R cycle duration of 15 s, but 5 s and 10 s sequences are also supported. +MSK144 short ("Sh") messages are intended primarily for 144 MHz, where +most pings are short. These messages do not contain full callsigns; +instead, they contain a hash of the entire transmitted message along +with a report. They are not encrypted -- the report is sent in the +clear along with the hash. Short messages are fully decodable only by +the station to whom they are addressed, as part of an ongoing QSO, +because only then will the received hash match that calculated using +the known strings for "My Call" and "DX Call" and the received report, +RRR, or 73. If you are monitoring someone else's QSO, you will not be +able to decode its Sh messages. + An MSK144 signal occupies the full bandwidth of a typical SSB transmitter, so transmissions are always centered at an offset of 1500Hz. For best results, selectable/adjustable Rx and Tx filters