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


K6ETA
 

Hi Andy,

I guess if you only want to talk about popularity and adoption I can kind of see that there's a point in there somewhere. Even that is a very strange conversation... because even popularity may be due to other things.

FT8 (and increasingly JS8Call) are 'popular' mostly due to the sunspot cycle minimum. When the bands come back they will probably be dropped like a damp rag. Why? because they are SO SLOW as to be nearly useless for actual communication beyond the brief exchange. When the bands are wide open, even a 'wet noodle' will outperform them. BUT, at the moment they are absolutely great for DX and very, very basic communication. Similarly in tough condx at any point in the sunspot cycle. I use them with a smile on my face.

I think popularity is an odd criteria for the value of a mode though.

If you have ever been on an NBEMS net using FLDigi, etc., it becomes very obvious that you want the *right mode for the mission*. That 'right mode' will change with condx, equipment and user skill. So the Software *Modem* programs and hardware (like VARA, ARDOP, PACTOR, etc.) become a part of the *skill* factor as they switch modes automatically so less skill is needed. So these *Modems*, not to be confused with modes, add an extra value.

FLDigi is like a Swiss Army Knife and any one mode may not be super popular, but its suite of modes is hugely useful to those who have learned some skills and have a variety of missions.

FT8 and soon JS8Call are the obvious evolution for the *mission* that was once carried out by PSK31 and RTTY before it. Those modes are still 'popular' during their various contests, but mode popularity is like a form of fashion. What's in vogue today will change tomorrow. The fact that RTTY sprints are still a thing speaks volumes though!

Anyway, it's an odd conversation and reminds me of comparing all camping gear whether it's for fishing, eating, sleeping or carrying heavy things around. All the gear serves a various set of needs.

73 de K6ETA




On 7/7/20 8:33 AM, Andrew O'Brien 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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