2 SAME TX
Speedster04 edited this page 2026-03-22 04:27:00 +01:00
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SAME TX generates and transmits Specific Area Message Encoding (SAME) digital headers — the protocol used by the US Emergency Alert System (EAS) and NOAA Weather Radio. SAME-capable receivers use these headers to selectively activate for alerts targeting their programmed county.

Controls

Field Description Range / Options Default
Org Originator code WXR, EAS, CIV, PEP WXR
Evt Event type (index 025) See table below RWT (index 0)
FIPS State 2-digit US state FIPS code 0099 39 (Ohio)
FIPS County 3-digit county FIPS code 000999 007 (Ashtabula)
Dur H Alert duration — hours 0099 00
Dur M Alert duration — minutes 0059 30

A live preview of the message string updates on screen as fields are changed.

Originator Codes

Code Meaning
WXR National Weather Service
EAS EAS Participant (broadcaster or cable system)
CIV Civil Authorities
PEP Primary Entry Point System (presidential-level)

Event Codes

# Code Event
0 RWT Required Weekly Test
1 RMT Required Monthly Test
2 NPT National Periodic Test
3 NST National Silent Test
4 NMT National Periodic Test
5 EAN Emergency Action Notification
6 EAT Emergency Action Termination
7 NIC National Information Center
8 ADR Administrative Message
9 AVA Avalanche Watch
10 AVW Avalanche Warning
11 BZW Blizzard Warning
12 CFW Coastal Flood Watch
13 CFS Coastal Flood Statement
14 DSW Dust Storm Warning
15 EQW Earthquake Warning
16 EVI Evacuation Immediate
17 FFW Flash Flood Warning
18 FFS Flash Flood Statement
19 FFH Flash Flood Watch
20 FRW Fire Warning
21 HLS Hurricane Statement
22 HUW Hurricane Warning
23 HUH Hurricane Watch
24 SVR Severe Thunderstorm Warning
25 TOR Tornado Warning

Message Format

The transmitted header has the form:

ZCZC-ORG-EVT-SS0CCC+HHMM-0010000-SAMETX--

where SS is the state FIPS, 0CCC is the county FIPS (the leading 0 is literal, part of the SAME county encoding), HHMM is the duration, and -0010000-SAMETX- are fixed placeholder fields for issue time and station ID. The full message is preceded by 16 preamble bytes and transmitted 3 times automatically, as required by the SAME standard.

RF Parameters

Parameter Value
Default frequency 162.550 MHz (NOAA Weather Radio)
Bandwidth 1.75 MHz
Sample rate 1.536 MSps
Modulation AFSK / FM
Mark tone 2083 Hz
Space tone 1563 Hz
Baud rate ~520.83 bps
FM deviation 5 kHz
Repeats 3×

Settings Persistence

Settings are saved to tx_same.ini.