WORLD FIRST VERIFIED QSOs TESTED ON-AIR ⚡ ASYNC TX 🦅 FAST TRACK 2 🏆 ADIF 3.1.7

FT2

The fastest digital mode ever created

First contact in the world completed on February 16, 2026. DECODIUM Fast Track 2 · Raptor Engine · −23 dB SNR · QSO in ~6 seconds · ADIF 3.1.7 Certified — SUBMODE=FT2.

2.47sASYNC TX
300msTX DELAY
~6sFULL QSO
~450QSO/HOUR
−23dBSNR
22:0ADIF VOTE
🏆 ADIF 3.1.7 🦅 Fast Track 2 Download ✈️ Join Telegram Learn More

FT2 NEWS

19MAY2026

🚀 DECODIUM 4.0 "Shannon" — PUBLIC BETA RELEASED · v1.0.261

This is it. After months of intensive development, the multi-decode engine has been completely rewritten in C++ from the ground up — delivering performance, stability and portability the old codebase couldn't provide. The Raptor Engine decodes down to −23 dB SNR. ASYMX mode — exclusive to FT2 — eliminates the Even/Odd sync constraint and opens a new era in digital modes. Cross-platform builds for Windows x64, macOS Apple Silicon, and Linux x86_64 (Qt 6.11) are ready to ship. This release also brings Ham Radio Deluxe/Icom data-mode stability, CAT startup reconnect reliability, FT2/manual QSO state hygiene, and UI refinements.

2,000+ operators · 500,000+ QSOs · One free, open project.

🚀 PUBLIC BETA v1.0.261 C++ REWRITE ASYMX · FT2
📥 Repository IU8LMC 📥 Repository 9H1SR → All downloads

73 de Martino IU8LMC & Salvatore 9H1SR — DECODIUM / FT2 Team · ARI Caserta

22MAR2026

🏆 ADIF 3.1.7 — FT2 Officially Certified — 22:0 Unanimous Vote

The ADIF Development Group voted 22 YES — 0 NO to officially include FT2 as a certified submode in ADIF 3.1.7. Historic record: highest participation ever in ADIF history. All major logging platforms voted YES: LoTW/ARRL (K1MU, K0GW), DXLab (AA6YQ), Log4OM (G4POP), Swisslog (EA3GCV), Cloudlog (MM9SQL), TR4W (NY4I), Wavelog (DJ7NT), DXLog (SM7IUN), Fldigi (W1HJK), eQSL (N5UP), and 12 more. Special thanks to Graham G3ZOD for guiding FT2 through the process with integrity.

🏆 ADIF 3.1.7 OFFICIAL 22:0 UNANIMOUS SUBMODE=FT2 → See all 22 voters
17MAR2026

🦅 DECODIUM SHANNON — Raptor Engine Released

The most significant update since launch. +2 dB sensitivity (−21→−23 dB SNR), 4× faster decode→TX latency (850→200 ms), QSO completion rate from ~30% to ~90%. TX timing fixed thanks to LZ2HV Christo's WAV analysis. Auto-sequence 100% working. Async collisions −80% with freq hopping ±25 Hz.

🦅 SHANNON BUILD 2603xx
08MAR2026

⚡ Asynchronous TX — FT2 Breaks Free from the Clock

DECODIUM 3.0 Codename Raptor features Asynchronous Transmission: FT2 transmits within 300ms of decoding — no period boundary, no NTP, no GPS. The waveform duration is optimised to 2.47s (−34% vs standard). 378 lines of legacy DT/NTP code removed. Full backward compatibility preserved.

⚡ ASYNC TX BUILD 2603080007
16FEB2026

First FT2 QSO in History!

IU8LMC e IZ8XXE completano il primo QSO FT2 al mondo su 40m. SNR -12dB, tempo totale 11 secondi.

WORLD FIRST
Official Certification — ADIF Development Group
22 MARCH 2026 · ADIF 3.1.7

FT2 is now an Official
International Standard

SUBMODE=FT2
YES votes
22
unanimous
100%
Approved
NO votes
0
zero against
Voters in favour 22 / 22 — 100%
📊
Historic record — The ADIF 3.1.7 vote on FT2 achieved the highest participation ever recorded by the ADIF Development Group: 22 voters, 22 yes, 0 no. The group spans major logging software platforms including LoTW / Trusted QSL (ARRL), DXLab Suite, Log4OM, Swisslog, Cloudlog, DXLog, TR4W, Wavelog, eQSL, Fldigi, and many more. Special thanks to Graham G3ZOD (FISTS / adif.org.uk) for guiding FT2 through the certification process with integrity and patience.
✅ The 22 Voters — ADIF 3.1.7
★
G3ZOD
Graham Smith
FISTS Log Conv. / adif.org.uk
KEY
✓
AA6YQ
Dave Bernstein
DXLab Suite
YES
✓
K1MU
Rick Murphy
Trusted QSL / LoTW
YES
✓
K0GW
Greg Widin
ARRL / LoTW
YES
✓
AD1C
Jim Reisert
AD1C Amateur Radio Software
YES
✓
G4POP
Terry Genes
Log4OM
YES
✓
N2AMG
Rick Ellison
N2AMG Software
YES
✓
VE3VRW
Don Agro
Dog Park Software
YES
✓
EA3GCV
Jordi Quintero
Swisslog
YES
✓
MM9SQL
Peter Goodhall
Cloudlog
YES
✓
NY4I
Tom Schaefer
TR4W
YES
✓
SM7IUN
Björn Ekelund
DXLog
YES
✓
DJ7NT
Joerg Dorgeist
Wavelog
YES
✓
W1HJK
Dave Freese
Fldigi
YES
✓
N5UP
Dave Morris
eQSL
YES
✓
LA3HM
Arve Olaussen
jLog / adif.org
YES
✓
DF3CB
Bernd Koch
DF3CB Software
YES
✓
K2DSL
David Levine
ADIF to Map
YES
✓
K2DW
David Westbrook
KJ4IZW Contest Scorer
YES
✓
W1UAA
Eugene Glukhov
HAMLOG.online
YES
✓
N0NB
Nate Bargmann
TLF
YES
✓
M0YMA
Andrew Banks
WWFF / WWFF Logsearch
YES
SUBMODE=FT2 — Now Official Worldwide
Log every FT2 QSO with SUBMODE=FT2 · ADIF 3.1.7 · adif.org.uk/317/ADIF_317.htm
500,000+ QSOs · 2,000+ operators · 40+ DXCC · World first: 16 February 2026
73 de IU8LMC Martino Merola — Creator FT2 — ARI Caserta — ft2.it
DECODIUM 3.0 · Latest Release

Fast Track 2

Raptor Engine · Build 2603xx · March 2026

+2 dB vs prev
−23 dB
SNR sensitivity
was −21 dB
4× faster
200 ms
Decode→TX latency
was ~850 ms
was ~30%
~90%
QSO completion rate
auto-seq 100% working
was ~180/h
~450
QSO per hour
2.5× improvement
Before
~30%
QSO completion · ~850ms latency
TX distorted · infinite 73 loops · async collisions
→
Fast Track 2
~90%
QSO completion · ~200ms latency
Clean TX · auto-seq fixed · freq hopping −80% collisions
🔧 Raptor Engine — What Changed
📡
Decoder sensitivity
−21 dB
→
−23 dB
⚡
Decode→TX latency
~850 ms
→
~200 ms
🔁
Decode passes / period
5 / 750ms
→
~20 / 187ms
✅
FT2 auto-sequence
broken
→
100% working
🔇
Infinite 73 loops
yes
→
eliminated (30s)
📻
TX signal distortion
yes (buffer)
→
clean
🔀
Async collisions
frequent
→
−80% (±25 Hz)
🎯
LLR Scale factor
2.83
→
3.2 (+0.5 dB)
📊
RMS metric normalization
none
→
3 ch (+1.0 dB)
📐 Shannon's Theorem — 1948
C = B · log₂(1 + S/N)

Claude Shannon proved that every noisy channel has a maximum information capacity — and that codes approaching this limit must exist. For 78 years, mathematicians searched for them.

1
Landauer 1961 — thermodynamic minimum: kT·ln(2) = 2.77×10⁻²¹ J/bit
2
Shannon 1948 — channel limit: Eb/N₀ ≥ −1.59 dB. No code can do better.
3
Turbo Codes 1993 (Berrou) — first practical proof Shannon was reachable. ~0.5 dB gap.
4
LDPC rediscovered 1996 — belief-propagation, no error floor, parallelizable. Surpasses Turbo codes.
5
LDPC (174,91) FT2 — 77 useful bits / 174 TX bits. Rate 0.44. 97 redundancy bits.
★
Raptor Engine 2026 — scale 3.2 + RMS norm + 5 passes → −23 dB SNR. Practical limit for 77-bit HF blocks.
Shannon absolute limit
Eb/N₀ = −1.59 dB
FT2 Fast Track 2
~4 dB from limit

"More power is not the answer. Better math is." — IU8LMC

📊 Performance Comparison — Raptor Engine vs Previous
Sensitivity
−23 dB SNR
+2 dB
Previous sensitivity
−21 dB SNR
baseline
QSO completion rate
~90% estimated
~90%
Previous completion
~30%
~30%
Decode timer
187 ms
4× faster
Previous timer
750 ms
750 ms
Async collisions
−80%
−80%
📐 Distance from the Shannon Limit — C = B · log₂(1 + S/N)
SystemEb/N₀ requiredDistance from ShannonBlock sizeNotes
Shannon absolute limit−1.59 dB0.00 dB∞ (theoretical)Physical boundary
Turbo Codes (Berrou 1993)~0.00 dB+1.6 dB~6,000 bitsFirst practical proof
LDPC long (5G NR)~0.10 dB+1.7 dB8,000–50,000 bitsIncompatible with FT2 T/R
⭐ LDPC (174,91) FT2 — Fast Track 2~2–3 dB~+4 dB77 bitsPractical limit for 77-bit HF
FT8 — same LDPC (174,91)~−1 dB (SNR)~+3 dB77 bits15s T/R cycle
CW+3–5 dB+6 dBvariableOperator skill dependent
SSB voice+10–15 dB>+10 dB—Far from Shannon limit
THE CONCLUSION

Within the real constraints of HF operation — 77 bits · 3.75s T/R · 167 Hz · ionosphere — DECODIUM Fast Track 2 with Raptor Engine is at the practical limit of Shannon's theorem. Nothing comparable exists today for these operating conditions.

"Every time you decode at −23 dB SNR, you are executing math at the physical limit of the universe." — IU8LMC

WHAT IS FT2

FT2 is a revolutionary digital mode for amateur radio, developed by IU8LMC with the support of ARI Caserta. It uses the same codec as FT8 and FT4 (77-bit payload, LDPC 174/91, 4-GFSK modulation) but compresses the transmission cycle to just 3.8 seconds.

⚡ EXTREME SPEED

Complete QSO in ~6 seconds with Fast Track 2. Theoretical rate of ~450 QSO/hour.

🔗 SAME CODEC

77-bit payload, LDPC(174,91), 4-GFSK modulation. The protocol core is identical to FT8/FT4.

📡 TESTED ON-AIR

Verified February 16, 2026. 2,000+ active operators, 500,000+ QSOs logged. QRZ Logbook active.

🏆 ADIF 3.1.7 CERTIFIED

Official ADIF submode: SUBMODE=FT2. Vote 22:0 unanimous. 22 March 2026.

TECHNICAL SPECIFICATIONS

ParameterFT8FT4FT2
T/R Cycle15 s7.5 s3.8 s
Effective TX Time12.64 s5.04 s1.89 s
Async TX Duration——2.47 s ⚡
Async TX Delay——~300 ms
Modulation8-GFSK4-GFSK4-GFSK
Bandwidth50 Hz83 Hz167 Hz
Payload77 bit77 bit77 bit
FECLDPC(174,91)LDPC(174,91)LDPC(174,91)
Sensitivity (Raptor)−21 dB−16.5 dB−23 dB ★
Full QSO~60 s~30 s~6 s
QSO Rate~60/h~120/h~450/h
ADIF SubmodeFT8FT4FT2 🏆

FT2 SENSITIVITY & PERFORMANCE

167 Hz bandwidth · 4-GFSK modulation · 3.8-second cycles · ⚡ Async TX: 2.47s waveform, 300ms delay, no clock sync
With Raptor Engine: −23 dB SNR — at the practical limit of Shannon's theorem for 77-bit HF blocks.

🦅 FT2 Sensitivity — Raptor Engine Fast Track 2
ModeAveragingTotal TimeSensitivityGain
FT2 Fast Track 2Raptor Engine3.8 s−23 dB ★+2 dB vs prev
FT24-period avg15.2 s−14.5 dB+5 dB
FT2Single period3.8 s−9.5 dB—
FT4Standard5.04 s−16.5 dBref
FT8Standard12.64 s−21.0 dBref

DOWNLOAD

🚀 DECODIUM 4.0 "Shannon" PUBLIC BETA v1.0.261

Complete C++ rewrite · Raptor Engine −23 dB SNR · ASYMX mode (FT2) · Cross-platform builds (Windows / macOS Apple Silicon / Linux x86_64). Released 19 May 2026.

Official mirrors

👨‍💻

Repository IU8LMC SHANNON

Martino IU8LMC — Protocol designer · Project lead

github.com/iu8lmc · v1.0.261
👨‍💻

Repository 9H1SR SHANNON

Salvatore Raccampo 9H1SR — Lead C++ developer · macOS/Linux maintainer

github.com/elisir80 · 1.0.261

Both mirrors host the same official Public Beta build · Windows x64 installer · macOS Apple Silicon DMG/ZIP · Linux x86_64 AppImage (Qt 6.11)

↓ Legacy Decodium 3.0 builds (Raptor)

📦

Decodium 3.0 Shannon (64 bit) 🦅 RAPTOR

Raptor Engine · −23 dB SNR · 5 decode passes · 4× faster

Build 2603xx · Windows 64 bit
📦

Decodium 3.Shannon (32 bit) 🦅 RAPTOR

Raptor Engine · −23 dB SNR · 5 decode passes · 4× faster

Build 2603xx · Windows 32 bit
🐧

Decodium 3.0 FT2 (Linux)

Beta software for Linux x86_64

AppImage · Linux x64 · GitHub
🍎

Decodium 3.0 FT2 (macOS)

Beta software for macOS · by 9H1SR

GitHub
🍓

Decodium 3.0 FT2 (Raspberry Pi) NEW

Compact portable FT2 stations · by LU7DZ

GitHub · Raspberry Pi

📚 DOCUMENTATION

Complete official documentation for DECODIUM 4.0 "Shannon" v1.0.262 — Quick Start guide, full User Manual, and advanced Reference Manual. Trilingual (IT / EN / ES) · All in PDF, HTML, DOCX and Markdown formats.

⚡ QUICK START 5-minute guide ~7 pages

For users who want to install, configure and make the first QSO in 5 minutes. Covers installation (Win/macOS/Linux), CAT setup, audio levels, FT8 first QSO, and the new 📞 CALL feature.

🇮🇹

Italiano (PDF)

PDF · A4 · ~370 KB
🇬🇧

English (PDF)

PDF · A4 · ~370 KB
🇪🇸

Español (PDF)

PDF · A4 · ~370 KB

Other formats: HTML · DOCX · Markdown

📖 USER MANUAL Complete · 10 chapters ~63 pages ⭐ RECOMMENDED

Full operating guide — installation, CAT/audio/PTT setup, FT8 workflow, FT2 protocol with DEEP/ASYMX/Quick QSO, 📞 CALL button, Call Roster, DX Cluster, PSK Reporter, Astro tools, themes, multi-instance, troubleshooting, and appendices (shortcuts, .ini, FT2 specs, changelog).

🇮🇹

Italiano (PDF)

PDF · A4 · ~1.0 MB · 63 pp
🇬🇧

English (PDF)

PDF · A4 · ~1.0 MB · 62 pp
🇪🇸

Español (PDF)

PDF · A4 · ~1.0 MB · 64 pp

Other formats: HTML · DOCX · Markdown · Split: Pt.1 · Pt.2

🔬 REFERENCE MANUAL Complete · Appendices A-J ~47 pages DEVELOPERS

Advanced technical documentation — full FT2 protocol spec (Costas, LDPC, CRC-14), complete decodium.ini reference (100+ keys), CAT command reference per radio (Kenwood/Yaesu/Icom/Elecraft + 30+ Hamlib IDs), UDP/IPC API for integrations (Log4OM, GridTracker), MultiRig CLI, build from sources, contributing guidelines, and 30+ troubleshooting scenarios.

🇮🇹

Italiano (PDF)

PDF · A4 · ~1.1 MB · 47 pp
🇬🇧

English (PDF)

PDF · A4 · ~1.1 MB · 47 pp
🇪🇸

Español (PDF)

PDF · A4 · ~1.1 MB · 46 pp

Other formats: HTML · DOCX · Markdown · Split: Pt.1 (A-E) · Pt.2 (F-J)

All documentation released under GPLv3 · Source Markdown available in manual/ directory · Index: manual/README.md

TEAM

IU8LMC
Developer & Creator
Concept, development, and on-air testing. Creator of DECODIUM 3.0 Fast Track 2.
SANTA MARIA CAPUA VETERE, CE
IZ8VYF
Pioneer #1
First FT2 QSO in history. 40m band, SNR -12 dB.
WORLD FIRST
IZ8XXE
Expert Advisor #2
Fastest QSO: 7 seconds on 80m band.
7 SEC QSO

Credits

Base software: DECODIUM 3.0 (open source, GPLv3)
Original protocol: Joe Taylor K1JT, Steve Franke K9AN
TX timing analysis: Christo LZ2HV — WAV comparative recordings
ADIF certification: Graham G3ZOD — FISTS / adif.org.uk
Raspberry Pi port: LU7DZ
macOS port: 9H1SR
AI tools: Claude (Anthropic) — development assistance
Team: ARI Caserta

CONTACT

📻 IU8LMC — Martino Merola
🏢 ARI Caserta — Santa Maria Capua Vetere, CE, Italy
✈️ Telegram Beta Group
🌐 ft2.it
💻 GitHub — DECODIUM 3.0
📋 ADIF 3.1.7 — SUBMODE=FT2 Official Spec