Re: Whats new in VARA 4 ? #VARA #qrp


kt67
 

RE:" awards are the biggest attraction to the average HF ham. "

Really???
Almost all the hams I know do not chase paper.(maybe 20-30 that I know well
enough to say that)

Maybe it's different in your area?

KT4WO

On 7/7/20, Andrew O'Brien <andrewobrie@...> wrote:
I was not intending to "compare" them. I have fun with all of them. I
was attempting to contrast the popularity of FT8 and 4 with the many
attempts over the years to get wider adoption of various digital modes that
have come and gone. My point was that most modes are minority interest and
that mass utilization of a particular mode is closely associated with award
chasing. Ardop, Winmor and others do have many users thanks to their
utility and a dedicated core group of emcomm types , but wider use is not
likely because the masses center on award chasing. Example: If magically a
keyboard QSO of ARDOP came out tomorrow with decoding capability five times
'deeper" than FT8 but for some reason, ARRL excluded it from DXCC, it would
not gain wide adoption. Perhaps a long-winded way of me pointing out that
awards are the biggest attraction to the average HF ham.

Andy K3UK



On Tue, Jul 7, 2020 at 11:16 AM Rick Muething <rmuething@...> wrote:

Andy,

Comparing FT8 and FT4 with VARA and P3, P4 is like comparing a golf cart
to a Porche!

FT8, FT4 are great for exchanging minimal information (call sign, signal
report, Grid square) and they do that well BECAUSE they are so SLOW and
narrow bandwidth (Higher Eb/No ....just as Claude Shannon describes in
his 1948 landmark paper on channel capacity. They satisfy a niche
especially if one is trying to make the maximum number of contacts at low
power each exchanging a very short message.

VARA, P3, P4 Transmit much larger data (text + attachments up to say 30
K
bytes) at ~1000 x (or more) than the FT8 or FT4 rate . They require
stronger signals than FT-4 of FT-8 and a wider bandwidth. These modes
again operate in exact accordance with Shannon's thesis (now proven).
They
are what you want to use if you are transmitting a sizeable
message/attachment or have to send a large amount of traffic. These
modes
are also automatically adaptive (changing their Eb/No and FEC level
automatically) so they can follow a changing path over 20 dB or more and
with varying amounts of multipath.

As hams we should all try to understand the basics of what Shannon
proved. It would make better use of our limited spectrum an different
bjectives. But comparing VARA and FT8 is like comparing an High
Definition
commercial TV transmission with a deep space photo taken from NASA
Voyager
using a 10 watt transmitter at 10 bits/second. Both have their uses but
are not in competition.

Rick Muething, KN6KB, Winlink Development Team
On 7/6/2020 2:46 PM, Andrew OBrien wrote:

I think FT8 and FT4 have shown that wide adoption of a digital mode is
achieved when popular awards , like DXCC , are associated with use of the
mode . If , for some odd reason, ARRL developed an award for receiving
email from 100 or more DXCC entities via VARA ... VARA would have many
more users . Despite VARA , Ardop, Winmor and Pactor having some
utilization in emcomm . these modes seem destined to be niche products in
the ham world .

Andy
K3uk

Digital modes via SDR = Multipsk or SDR-Radio.com
------------------------------



--
Andy



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