[NLRS] FYI - WSJT-X 2.4.0

[Bill ND0B]

Good afternoon,

A group of us have been beta testing Q65 on 6m.   The results are interesting and there are a couple of things to be aware of as you start playing with it.   It is great to see this has evolved enough they decided to get an RC out.   

A lot of the initial experimentation was with 30 second periods and the narrowest bandwidth, Q65-30A.   This proved very immune to meteor scatter pings and allowed pretty reliable minimal communications out to 1200 miles or more with no Es.    Best performance seemed to be midday and we tended to run power on these contacts

More recently we started experimenting with longer periods and wider bandwidths with Q65-120E being the most commonly used.   We quickly found that the same contacts that were requiring several hundred watts on Q65-35E could be done with a be tens of watts on Q65-120E.   In one experiment with even longer sequences I exchanged a couple of decodes with a station 1350 miles away using Q65-300A, this was before we realized the advantages of spreading the signal out.  

A couple of gotchas as you start playing with this:

1.  The decoder loves to grab whatever is handy for a sync signal regardless of it is a sync signal or not.   Any interference with vertical lines on the waterfall is problematic.   As a consequence careful selection of frequency AND using a very narrow FTol is advantageous.   We routinely run with FTol of 20.

2.  The message eats most of the allotted time and the decoder takes a while.   These two things together mean it is a fairly regular occurrence that the decode of the previous RX does not occur until the current TX is well under way.   My view on that is so be it, the contact can sequence ahead on the TX after and if the intent is to finish quickly we already have FT8. 

I see this mode as it evolves as being a workhorse for rare grid activation especially when targeting a few folks who really need the grid (my recent working of CM93 being a prime example).   As you play with this you will be truly amazed at its capability as long as you keep in mind what it is targeted for. 

73 de Bill ND0B


-----Original Message-----
From: nlrs-bounces at mailman.qth.net <nlrs-bounces at mailman.qth.net> On Behalf Of Jon Platt via NLRS
Sent: Wednesday, February 3, 2021 9:53 AM
To: nlrs at mailman.qth.net
Subject: [NLRS] FYI - WSJT-X 2.4.0

The new release of WSJT-X 2.4.0 "will introduce Q65, a digital protocol designed for minimal two-way QSOs over especially difficult propagation paths".   Using ionospheric scatter this new digital mode will allow 100 watt, yagi based 6m stations to work distances of up to around 1600km on a dead band.  Yes, its digital and yes, it will impact how we operate VHF.   The release team has a Quick Start guide that provides lots of good info, see the link provided below. 73, JonW0ZQ https://physics.princeton.edu/pulsar/k1jt/Q65_Quick_Start.pdf
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