I don’t use AGC on FT8 for the reasons you expressed plus that without it,
you can decode weaker signals. After all, it is a weak signal mode.
Chuck W5PR
On Thu, May 2, 2019 at 5:28 PM Mark Spencer <mark@alignedsolutions.com>
wrote:
> From a VHF contesting perspective I'm not completely convinced that all
> signals will always be decoded on a crowded FT8 "channel" with a mixture of
> very weak and very strong signals.
>
> I'm thinking receiver AGC (if it is used) and or the dynamic range of
> typical "sound cards" may lead to very weak signals not being decoded if
> there are very strong signals present at the same time as very weak signals
> ?
>
> As I can't control how other operators configure their equipment or what
> near by signals they may have to deal with, I am not hugely enthused about
> running FT8 from out of the way locations during contests as I am concerned
> my weak signals may not be decoded in practice during typical contest band
> conditions.
>
> I am aware that some operators In out of the way places have tried running
> FT8 on "different frequencies" which in my view would go a long way to
> addressing my concerns but my understanding is most other stations were
> reluctant to QSY.
>
> The opinions and experiences of others may differ from mine. To be
> transparent I haven't put a huge amount of thought into this matter and if
> anyone fundamentally disagree with I have written I'd be happy to discuss
> further (preferably off list) in case I am missing something.
>
> I suspect my use case may be rather unique.
>
> 73
>
> Mark S
> VE7AFZ
>
> mark@alignedsolutions.com
> 604 762 4099
>
> Mark Spencer
>
> Aligned Solutions Co.
> mark@alignedsolutions.com
> 604 762 4099
> > On May 2, 2019, at 11:19 AM, Michael Clarson <wv2zow@gmail.com> wrote:
> >
> > Jay: The argument that SSB is so much faster than FT8/4 and stations
> should
> > switch to SSB when the band is open is not universally true. It is if you
> > are the station running guys on a specific frequency, but NOT if you are
> > one of the poorer equipped calling the running station. When running low
> > power, it will often take 10 or more minutes to work a station on SSB
> when
> > the band is open -- I am competing with many stations with better signals
> > than me. But, on FT8/4, everyone gets decoded, and my rate actually goes
> > up. --Mike, WV2ZOW
> >
> >> On Thu, May 2, 2019 at 1:48 PM Jay RM <w9rm@calmesapartners.com> wrote:
> >>
> >> 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
> >
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting
|