I'm with your thought, Gary and if you and others permit me, I would add
that FT8 is (should be) seen as a low power high S/N efficient
transmission mode, then it is particularly useful and welcomed for
modest ham-radio stations like mine.
If now, to work a DX Expedition which is using SFox we would need a
multi-elements Yagi beam and at least 500 Watts of RF power, this
beautiful "FT8 concept" disappear!
---
*73 de Marco, PY1ZRJ (former IK5BCU)*
**
Il 24/08/24 18:12, Gary via wsjt-devel ha scritto:
Exactly. The reduced overall sensitivity compared to 3 stream regular
F/H was at play in my case. On 3 streams, they decoded on regular F/H
at -17. Weak, but well within the -24db decoder limit. A -17db
signal on Super F/H is outside of that decoder's limit of -16. It
makes a difference for those of us forced to use marginal stations.
Also, the 1500hz bandwidth makes it more prone to QRM, as I see it.
I hope that DXPeditions from now on will not be using S/FH
exclusively, or myself and a lot of other small stations are going to
be left out, unless the SFX runs some power. Like 40-100w at least.
I heard that N5J was only running 10w. That could have been a big
part of the problem, if true.
73 de Gary - W9BS
On 8/24/2024 4:50 PM, Jim Shorney via wsjt-devel wrote:
It is a matter of deciBels as has been documented. Each time a stream
is added in multi-stream there is a multi-dB power hit on all
streams. This is what SF avoids but TANSTAAFL. You do lose some
sensitivity but at that point you would probably not be hearing
multi-stream FH either. It seems like you were a victim of
propagation. If you were copying three streams of FH you probably
could have copied SF under the same conditions. Just a guess as there
are multiple factors in play. I was decoding SF more reliably than
anything over 2 FH streams. It is rare that I am able to copy three
or more FH streams when prop is poor. Signals have to be very good.
That is not the fault of the software, it is the limitations imposed
by my antenna system and local noise floor vs. propagation conditions.
73
-Jim
NU0C
On Sat, 24 Aug 2024 12:10:02 -0400
Gary via wsjt-devel <wsjt-devel@lists.sourceforge.net> wrote:
Perhaps it is a problem when running 5 streams. But my experience was
just the opposite. I could never hear them on SFox on any band.
Admittedly, I run a low profile station with an attic antennas. From
this perspective, SFox was a huge disappointment. It wasn't until they
switched to regular fox near the end of their deployment that I was
able
to finally work them on 17 and 30. They were running 3 streams at the
time. Never decoded them once on Superfox on any band, after
frustratingly listening for them all week.
73 de Gary - W9BS
On 8/24/2024 11:51 AM, Jim Shorney via wsjt-devel wrote:
But the same can be said of multi-stream F/H. I can say with
certainty that I have Super contacts in the log with N5J that I
would not have if they had been using multi-stream.
On Sat, 24 Aug 2024 13:48:02 +0000 (UTC)
Greg Chartrand via wsjt-devel <wsjt-devel@lists.sourceforge.net>
wrote:
The bottom line is SF mode IS self defeating when/where conditions
are marginal AND they are always marginal somewhere in the world
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