Thanks to all who participated in yesterday's FT4 mock-contest practice
session -- and especially to those who provided useful feedback. It is
much appreciated!
Everyone likes the 7.5 s T/R sequences, which provide operators with
significantly more human-interaction time than in previous revisions of
FT4. Users also appreciated the sensitivity improvements and a larger
range of acceptable time offsets, DT.
Steve, K9AN, spent most of his time just watching what was going on.
During the test period he decoded some 25,300 FT4 transmissions. Steve
prepared histograms of DT and S/N values for these decodes, and I've
posted them here:
http://physics.princeton.edu/pulsar/k1jt/dt.png
http://physics.princeton.edu/pulsar/k1jt/snrs.png
It seems that we have the WSJT-X timing behavior under good control on
all supported platforms -- 95% of recorded DT values fall in the range
+/- 0.25 s, and 99% in the range +/- 0.5 s. The range of measured S/N
values extends downward to -21 dB. Its distribution is consistent with
our sensitivity measurements based on simulated data, which show 50%
probability of decoding down to -17.5 dB.
I operated for about three hours using 100 W and a dipole. I copied
transmissions from 263 unique callsigns and made 143 QSOs in 29 States,
5 Canadian Provinces, and 15 DXCCs.
A few problems were reported. The most common one was caused by a few
casual operators who had not enabled "RTTY Roundup" contest-style
exchanges. Several operators found that activating the "Best S+P"
option occasionally caused the program to select a potential QSO partner
who had not called CQ.
Summary comment from K1HTV: "Looks like RC7 is a keeper, as far as
performance, with no problems at all."
We will soon address all remaining issues we're made aware of. I
believe we are on a good path toward a General Availability (GA) release
of WSJT-X 2.1.0 by mid-July.
Please remember that WSJT-X 2.1.0 and FT4 are NOT to be used during the
ARRL June VHF contest (June 8-10) or ARRL Field Day (June 22-23). For
these events you should use WSJT-X 2.0.1 and FT8.
-- 73, Joe, K1JT
_______________________________________________
wsjt-devel mailing list
wsjt-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/wsjt-devel
