The 'need for FT speed' reflects the huge QSO/hour disadvantage FT8 has vs
SSB when the band is open. Many 6M op's have foolishly abandoned SSB
during contests, so the introduction of FT4 is an attempt to speed things
up a bit. We'll see whether the mode can ultimately live up to it's
promise. With all the mouse movements and click-click required, I doubt
FT4 will perform anywhere near as well as an experienced human op using
SSB. We will see.
Remember, FT4 is advertised as a 'contesting' mode. The idea of a contest
is to maximize your score. The best way to maximize a score is to run
contacts as fast as possible over the duration of the contest. So, one
should use the fastest mode for the given conditions. When the band is
closed or marginal, you want to use the most sensitive mode. This could be
JT65 if the potential contact base is limited or FT8 if there are many weak
stations to work (or CW, of course). As the band opens, there will be a
point where the intelligent operator needs to make a switch from
'sensitivity' to 'speed'. Should this switch be FT8 to FT4 ? No, because
SSB is faster and certainly sensitive enough during a Es opening.
If this is the case, why does FT4 really exist as a contest mode ? It's
not as good for weak signals as FT8 and it's most likely not as fast as
SSB. "Because we can" is not a sufficient answer for something that has
shown the capability to totally upset the status quo of an entire band in a
negative way (condensing an entire band full of operators on to what is
realistically one frequency).
-W9RM
Keith Morehouse
via MotoG
On Thu, May 2, 2019, 10:59 AM Mark Spencer <mark@alignedsolutions.com>
wrote:
> It is interesting to me that the new JT modes seem to be emphasizing
> speed. From my perspective I view the digital modes as a means of
> completing qso's that can't be done with traditional analog modes and am
> happy to trade off speed for better weak signal performance. Or I like
> really fast modes that can exploit brief propagation modes such as meteor
> scatter outside of a major meteor shower.
>
> That being said the activity levels where I live are low enough that if I
> manage to work more than 10 stations while activating a rare grid in VE7
> land I consider the trip to be a great success (: So my perspective may
> be a bit unusual (:
>
> I'll be curious to see how this new mode works out in practice. I
> appreciate the efforts of the developers and early adopters / testers.
>
> In the mean time I am expecting to use JT9 on 50 MHz this season.
>
> 73
> Mark S
> VE7AFZ
> mark@alignedsolutions.com
> 604 762 4099
>
> > On May 2, 2019, at 9:29 AM, Aa4zz via VHFcontesting <
> vhfcontesting@contesting.com> wrote:
> >
> > Per Joe Taylor's talk at the VHF Super Conference
> > The faster speed comes with a trade off of 4.5db less sensitivity.
> > Of course for many QSO's that will not matter, but on weak signals it
> may.
> > 73 Paul AA4ZZ
> >
> >
> >
> >
> > Message: 1
> > Date: Mon, 29 Apr 2019 10:47:01 -0700
> > From: Brian Dickman <brian.dickman@gmail.com>
> > To: VHFcontesting@contesting.com
> > Subject: [VHFcontesting] FT4 mode
> > Message-ID:
> > <
> CAJnrbTwEcfmp0MVKXZV7kSc8OFhvTK9w-4YVE+hUHu_mvveMzg@mail.gmail.com>
> > Content-Type: text/plain; charset="UTF-8"
> >
> > Since the topic hasn't appeared on this list yet, I figured it would be a
> > good idea to make folks here aware of the pending WSJT FT4 mode in case
> > they hadn't seen it already.
> >
> > The tl;dr:
> > * 2.5X faster than FT8
> > * Same contesting features as FT8
> > * Automatic search and pounce mode
> > * 144.170MHz proposed 2m frequency
> >
> > To read more, here's a couple links:
> >
> > *
> >
> http://www.arrl.org/news/faster-more-contest-friendly-ft4-digital-protocol-to-debut-in-a-week
> > * http://physics.princeton.edu/pulsar/k1jt/FT4_Protocol.pdf
> > *
> >
> http://www.southgatearc.org/news/2019/april/video-of-ft4-talk-by-joe-taylor-k1jt.htm#.XMc36OhKhaQ
> > (video
> > of a club talk Joe Taylor made about FT4)
> >
> > 73,
> > --
> > Brian AF7MD
> >
> >
> >
> >
> > ------------------------------
> >
> > Subject: Digest Footer
> >
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> >
> >
> > ------------------------------
> >
> > End of VHFcontesting Digest, Vol 197, Issue 2
> > *********************************************
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