27-04-2019, 09:34 AM
Joe Taylor K1JT has announced a new digital mode, FT4, which is 2.5 times faster than FT8
FT4 is an experimental digital mode designed specifically for radio contesting. Like FT8, it uses fixed-length transmissions, structured messages with formats optimized for minimal QSOs, and strong forward error correction.
T/R sequences are 6 seconds long, so FT4 is 2.5 faster than FT8 and about the same speed as RTTY for radio contesting. FT4 can work with signals 10 dB weaker than needed for RTTY, while using much less bandwidth. FT4 message formats are the same as those in FT8 and encoded with the same (174,91) low-density parity check code. Transmissions last for 4.48 s, compared to 12.64 s for FT8.
Modulation uses 4-tone frequency-shift keying at approximately 23.4 baud, with tones separated by the baud rate. The occupied bandwidth, that containing 99% of transmitted power, is 90 Hz
Further information on FT4 is at http://physics.princeton.edu/pulsar/k1jt...otocol.pdf
(SouthGate)
From text edition for April 28 2019 - VK NATIONAL NEWS BROADCAST ON VK1WIA : http://www.wia.org.au/members/broadcast/wianews/
Also in Weekly news from the WIA: MP3 edition of news available at: http://www.wia-files.com/podcast/wianews-2019-04-28.mp3 Text edition:
What software supports FT4 ? WSJT-X 2.1.0
FT4 is an experimental digital mode designed specifically for radio contesting. Like FT8, it uses fixed-length transmissions, structured messages with formats optimized for minimal QSOs, and strong forward error correction.
T/R sequences are 6 seconds long, so FT4 is 2.5 faster than FT8 and about the same speed as RTTY for radio contesting. FT4 can work with signals 10 dB weaker than needed for RTTY, while using much less bandwidth. FT4 message formats are the same as those in FT8 and encoded with the same (174,91) low-density parity check code. Transmissions last for 4.48 s, compared to 12.64 s for FT8.
Modulation uses 4-tone frequency-shift keying at approximately 23.4 baud, with tones separated by the baud rate. The occupied bandwidth, that containing 99% of transmitted power, is 90 Hz
Further information on FT4 is at http://physics.princeton.edu/pulsar/k1jt...otocol.pdf
(SouthGate)
From text edition for April 28 2019 - VK NATIONAL NEWS BROADCAST ON VK1WIA : http://www.wia.org.au/members/broadcast/wianews/
Also in Weekly news from the WIA: MP3 edition of news available at: http://www.wia-files.com/podcast/wianews-2019-04-28.mp3 Text edition:
What software supports FT4 ? WSJT-X 2.1.0
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
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http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.