New FT4 protocol hits the airwaves

Back on the 23rd of April 2019, I had a post up about the new FT4 protocol from Joe Taylor & the WSJT team.. https://ei7gl.blogspot.com/2019/04/new-ft4-protocol-announced-for-digital.html

A new Beta version of the WSJT-X software was released on Monday the 29th of April and there seems to be a lot of interest in it already.

I took three snapshots of the activity levels on the 20m, 30m, 40m and 80m bands on the evening of the 30th of April and the morning and afternoon of the 1st of May. The results are shown in chart below...

As can be seen, there are already a substantial number of people using FT8 after just 48 hours. The main band is 20m followed by 40m.

The general release for FT4 will be in July of 2019.

Although it was designed for digital contesting, it will almost certainly be used outside of contests when it is finally released. As the FT4 transmissions are 6 seconds in length as compared to 15 seconds for FT8, it is likely to be used on busy bands where the FT8 frequency is crowded and the signals are strong...i.e. 20m & 40m.

Will FT4 replace FT8 in time? FT8 does have the advantage of being more sensitive but it's hard to imagine it not being used on say 50 MHz where FT4 is two and half times faster and people are trying to work as many stations are possible during the short openings.

The website for the software is http://physics.princeton.edu/pulsar/k1jt/wsjtx.html

FT4 intro...

New FT4 protocol announced for Digital Contesting

On the 22nd of April 2019, a PDF document was released outlining the new FT4 Protocol for Digital Contesting. Link.... http://physics.princeton.edu/pulsar/k1jt/FT4_Protocol.pdf

Key points...

1) Transmissions last for 4.48 seconds as compared to 12.64 s for FT8.

2) Works at about the same speed as RTTY for contesting.

3) For a rough comparison with RTTY, it was noted that in simulated mid-latitude moderate conditions RTTY has been shown to yield character error rates less than 10% only when SNR exceeds –1 to +4 dB, depending on the software modem in use. FT4 offers a sensitivity advantage of about 10 dB over RTTY.

4) As many as 50 stations can operate in a 3 or 4 kHz passband with little interference, even when signal strengths differ by as much as 60 dB.

5) July 15th 2019: General Availability (GA) release of WSJT-X 2.1.0 and FT4.

From the document..."FT4 is a special-purpose mode designed for rapid-fire contest QSOs. It serves this purpose very effectively, but like FT8 the mode is not useful for more extensive conversations. FT4 uses much less bandwidth than RTTY and provides reliable decoding at much lower signal levels. Stations using low power and compromise antennas can participate effectively in a contest using FT4."

Thoughts... 
It will be interesting to see how this develops and what impact it will have. Will it help kill off RTTY? Will it be used outside of contests?

The software can be downloaded here... http://physics.princeton.edu/pulsar/k1jt/wsjtx.html

Update... See this video presentation about FT4 from Joe Taylor K1JT. The piece about FT4 starts around 14 mins...