I am glad someone else agrees with me about the potential effects of AGC in
this context (:
73
Mark S
VE7AFZ
mark@alignedsolutions.com
604 762 4099
> On May 2, 2019, at 3:55 PM, Chuck Dietz <w5prchuck@gmail.com> wrote:
>
> 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
>> >
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