Re: [wsjt-devel] SuperFox vs Fox

[Marco C. <PY...@ou...>]

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 <wsj...@li...> 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 <wsj...@li...> 
>>>> wrote:
>>>>> The bottom line is SF mode IS self defeating when/where conditions 
>>>>> are marginal AND they are always marginal somewhere in the world
>>>