Joseph Taylor

Joseph Taylor

FT8 Developer

Nobel Laureate

FT8

BUY AMERICAN!

The last 10 FT8 QSO's are with:
Call SignCountryBandDateTime (UTC)
N0RQVUnited States20m03/24/201819:51:00
N5KUCUnited States20m03/24/201819:49:00
N5LYJUnited States20m03/24/201815:39:00
NK4LUnited States20m03/24/201812:40:00
KA9JACUnited States20m03/24/201812:35:00
W4EBBUnited States20m03/19/201821:03:00
K7MEEUnited States20m03/19/201820:59:00
WA4AROUnited States20m03/19/201820:54:00
KB0VHAUnited States20m03/19/201820:41:00
N2BJUnited States20m03/19/201820:37:00

 

Interesting Ft8 Digital Mode Videos

 

Have you caught the FT8 bug yet?? I have and I love this new digital mode from Joe Taylor, K1JT and Steve Franke, K9AN. FT8 (Franke-Taylor design, 8-FSK modulation) is designed for situations like multi-hop Es where signals are weak and fading, openings may be short, and you want fast completion of reliable, confirmable QSOs. And the best part about FT8 is that you can complete a QSO in <2 minutes!

 

According to J. Taylor, the important characteristics of FT8 are:

  • T/R sequence length: 15 s
  • Message length: 75 bits + 12-bit CRC
  • FEC code: LDPC(174,87)
  • Modulation: 8-FSK, keying rate = tone spacing = 5.86 Hz
  • Waveform: Continuous phase, constant envelope
  • Occupied bandwidth: 47 Hz
  • Synchronization: three 7x7 Costas arrays (start, middle, end of Tx)
  • Transmission duration: 79*2048/12000 = 13.48 s
  • Decoding threshold: -20 dB (perhaps -24 dB with a priori decoding, TBD)
  • Operational behavior: similar to HF usage of JT9, JT65
  • Multi-decoder: finds and decodes all FT8 signals in passband
  • Auto-sequencing after manual start of QSO

Compared to the so called slow modes (JT9, JT65, QRA64), FT8 is a few dB less sensitive but allows completion of QSOs four times faster. Bandwidth is greater than JT9, but about 1/4 of JT65A and less than 1/2 QRA64. Compared with the fast modes (JT9E-H), FT8 is significantly more sensitive, has much smaller bandwidth, uses the vertical waterfall, and offers multi-decoding over the full displayed passband. Features not yet implemented include signal subtraction, two-pass decoding, and use of a priori (already known) information as it accumulates during a QSO." (Source: Wikipedia)

 

Joe Taylor also released an update to his software program WSJT-X to support FT8. I absolutely love this program compared to the JT65-HF that I have been using for JT65. It's more flexable and has an automatic sequencer so you can start your QSO and sit back while the software does the rest!

 

FT8 Screen

 

It also has a nice waterfall screen too!

 

FT8 Screen

 

 

You can download the new WSJT-X at: https://physics.princeton.edu/pulsar/k1jt/wsjtx.html

 

There are a number of operating frequencies for FT8 on the HF bands. They are:

Band Frequency Comments
10 meters 28074 kHz Upper Sideband
12 meter 24915 kHz Upper Sideband
15 meters 21074 kHz Upper Sideband
17 meters 18100 kHz Upper Sideband
20 meters 14074 kHz Upper Sideband
30 meters 10136 kHz Upper Sideband
40 meters 7074 kHz Upper Sideband
80 meters 3573 kHz Upper Sideband

 

Enjoy this new mode. Oh and I worked over 30 states in just 3 days. This is a quick way to reach WAS too! FT8 is now supported in LoTW.

 

 


© 2018, Jonathan Tucker N8MDP. All Rights Reserved.