Whats new in VARA 4 ? #VARA #qrp
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Whats new in VARA 4 , live as from 1 July
Faster high rate transfer and lower s/n weak signal performance Completely re-worked protocol 2.3 KHz b/w : 16 speed levels New 500 Hz B/W mode : 13 speed levels Mixed B/W connections possible -winlink - bpq Unlicensed access remain at MFSK 2.3 K 175 / 500 Hz 88 Net rate V4 deploys a all new re configured, non backward compatible protocol ,providing a faster and streamlined Data /Ack sequence with new symbol rates / carrier configurations , supporting , higher transfer rates and enhanced weak signal performance to that expected of conventional chat-mode's Level 16 , of the 2.3K mode, provides a net rate of 7050 BPS with 49 on air carriers , running at symbol rate of 42 Baud the 49 carrier modem is engaged at level 10 with 2011 BPS in keeping with HF channel compatibility , none of the speed levels deploy symbol rates over 94 B, round ''50 being the norm The new 500 B/W mode reaches a maximum throughput of 1534 BPs with 11 carriers , 42 baud symbol rate, making for a very robust connection . primarily provided to allow use in the narrowband mail box areas , in association with email/file transfer . Interestingly level 1 , 2.3 K and level 1 500 Hz b/w is set at 18 BPs at the same s/n ratio, for each mode ...In discussions round s/n , the new low sensitivity levels/data rate is felt to exceed that offered by the OLIVIA data mode , which, in terms of payload delivery , offers a very high level of 'link completion' under adverse conditions, CHAT users, are provide , only with access to the 2.3 K b/w mode , winlink or BPS is required to access the 500 version , however, the 2.3 modem now provides close or if not below the noise live qso and file transfer . this coupled with the off air 'monitor option' , gives reasonable round table performance, fast arq , providing error free conversation at amtor rates , at weak signal levels, without the detection and lock time delays of conventional 'robust' 'chat' modes , QRP , Unregistered the modem is limited to phase continuous MFSK, providing compatibility with non lienera TX , eg class C, E/D , OFDM require's linear path . providing an alternative to Olivia dx qso's , noting [Olivia has a phase component to the modulation waveform and requires a Linera TX path] .....Noting of course, Vara requires a full linear Tx&Rx path , once the speed ranges , engauge the OFDM modem registered or not, the QRP aspect remains available l MF/MF-Ecomm's The 500Hz Bw meets data B/W requirement's ** for the MF band , and could provide E-COMM's making use of the enhanced weak signal aspect , MFSK 2.3 K 175 / 500 Hz 88 Net rate its unusual for High power MF Tx to be linear , but , if so, then full use could be made . noting, there is no facility to change the TX tone mid band , perhaps not so much of a issues these days ** May change region to region, Modem rate / level chart Mixed mode connection, accessed via option choices in the modem set up , where possible, gateway connection at 2.3 K is advised , to minimise access time . The 500<->2300 gateway compatibility option can be used by Sysops to monitor both, 2300 and 500 simultaneously. the modem will detect and configure to the calling station WINLINK The modem requires a minimum Dwell time of 4 seconds , when using the TRI-Mode function VARA is now included in the Forwarding facility VARA FM , VARA 9600 , VARA SAT all remain as was 73 -Graham g0nbd
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Andrew O'Brien
For those of us that have previously paid for earlier versions of VARA, is this new version simply a continuation or do we have to pay again ? Andy K3UK
On Sun, Jul 5, 2020 at 4:17 PM Graham <g0nbd@...> wrote:
-- Andy
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Andrew O'Brien
It’s OK, I figured it out . I downloaded the new version on to a new PC but also put a copy on my old PC. The old PC automatically recognized that I had previously purchased the software .
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Andy K3UK
On Jul 5, 2020, at 5:51 PM, Andrew O'Brien via groups.io <andrewobrie@...> wrote:
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Graham
That's ended well -
I think the call is the licence , and can have various -/ all the modems and versions are covered by the same key, At over 100 baud, the non registered set-up should provide adequate , two way chating , pity , really , after spending hours running dev versions over the past years , there no real use for the modem in the UK A simple chat interface that links the 500 Hz could have various uses , the vara chat still links only to the 2.4 K 'vara is not a chat mode' to quote some one .. 73 -Graham
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Andrew OBrien
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 .
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Andy K3uk
On Jul 6, 2020, at 3:29 PM, Graham <g0nbd@...> wrote:
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Rick Muething
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 .
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Andrew O'Brien
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
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kt67
RE:" awards are the biggest attraction to the average HF ham. "
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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
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KD7JYK DM09
"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?" I've been in radio since 1977, and a "Ham" since 1994. I've HEARD paper chasing is an interest, even read about it a few times, never seen, directly heard from those that do it, or personally known of one that does it, whether QSL card, awards, certificates, et cetera. I imagine, among those that do it, it's a thing, however, across scores of clubs as a member, and officer, hundreds of forums, a good portion of the country that I've traveled, the operating I've done, and the DX my wife chases, I can safely say I've only ever heard about it, perhaps a half dozen times, in 40+ years. If it's a thing, it's not a big, or well known thing, even across the radio services. Kurt
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Graham
On Tue, Jul 7, 2020 at 04:33 PM, Andrew O'Brien wrote:
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.Actually there already is such a thing , and its adif listed , though there is a issue with Semantic change dependant on location .. the most prolific deployment can be found on the 11 meter band ... 73-G
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K6ETA
Hi Andy, 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. 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:
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Tomasz
Hello.
I have a problem with Vara HF V4.03 settings with Winlink Express. With the previous version and my settings, everything works. Now winlink does not control the PTT of the Vara modem. Vara Terminal with the same PTT settings works with Vara HF V 4.03 without any problem. RMS works and controls PTT in other ardop winmor modes etc. What could be the problem? All the Best, 73 SP5LOT / Tomek
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Graham
Tomeck ,
Ros, suspects , there is another application runinning that has acquired the com port Needed to address the modem ... Might need a little knife and forking , in the device manager to see what is Using what resource Or post into the vara user groups, which is in Google groups , should get a more tailored response 73 Graham G0nbd
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Andrew OBrien
if you are using paired virtual ports , try removing the paired ports and then re-create the pair
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Andy
On Jul 12, 2020, at 10:13 AM, Graham <g0nbd@...> wrote:
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Tomasz
Thank you for the quick reply !
I will look for a solution. 73 Tomek SP5LOT
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Interesting comments from LA gateway using the 500 mode
Link maintaining traffic [ qso] flow down to -20 dB s/n over quite difficult high latitude paths , oddly , the latest simulator tests , stop at -5 db s/n ? -20 .. Thats a significantly Low signal level, well inside what could be classed as weak signals mode , for comparison the op05 opera beacon 30 seconds , and the 'qso mode 15 chrs plain text 60 second tx time line. both run to -20 dB possible -23 dB As example , F5ZAL is a 2 meter fixed beacon , running 10 watts to 'halo' type ae with 360 deg coverage , op05 / 30 second mode, being spotted at 546 Km, at levels that would support the Vara 2300 and 500 modem F5ZAL F5SN 2m OPERA 546 km 18:01:24
2020-07-22 19:53:18 F5ZAL AA F5SN JN27RB 0 144.475 -15 Op05_||||||||_~16dB
2020-07-22 18:24:33 F5ZAL AA F5SN JN27RB 0 144.475 -13 Op05_||||||||||||_~14dB
2020-07-22 18:05:01 F5ZAL AA F5SN JN27RB 0 144.475 -10 Op05_||||||||||||||||||_~11dB
2020-07-22 18:01:28 F5ZAL AA F5SN JN27RB 0 144.475 -16 Op05_||||||||_~16dB
2020-07-22 12:50:50 F5ZAL AA F5SN JN27RB 0 144.475 -15 Op05_||||||||||_~15dB
2020-07-22 12:29:32 F5ZAL AA F5SN JN27RB 0 144.475 -10 Op05_||||||||||||||||||||_~10dB
2020-07-22 12:17:06 F5ZAL AA F5SN JN27RB 0 144.475 -16 Op05_||||||||_~16dB
2020-07-22 12:15:20 F5ZAL AA F5SN JN27RB 0 144.475 -17 Op05_||||||_~17dB
2020-07-22 12:02:54 F5ZAL AA F5SN JN27RB 0 144.475 -16 Op05_||||||||_~16dB
2020-07-22 11:29:11 F5ZAL AA F5SN JN27RB 0 144.475 -17 Op05_||||_~18dB
2020-07-22 11:25:38 F5ZAL AA F5SN JN27RB 0 144.475 -15 Op05_||||||||||_~15dB
73- Graham g0nbd
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Graham
Trick's of the trade
The low speed ranges of the 2.3KHz wide mode , are designed for a filter bandwidth of ~ 1.5 KHz , higher levels requiring the full channel As user data and experiences are gathered, one aspect has become clear , the full 2.4 KHz voice channel is not always fully available, hence to ensure maximum efficiency , ie power transfer in the lower ranges , the modem allows for constricted channel bandwidth, either by the various user interfaces or filter bandwidth Thus ensuring the bedrock -20 dB is achievable , independently of equipment irregularities , two images make the point , using the opera waterfall display , with mouse pointer/frequency as measurement tool , First ic7100 with 2.5 KHz usable bandwidth in data mode using digital filtering . direct USB link to pc The second , FT897D offering a much rounded response with app 1.5 KHz usable bandwidth** using usb soundblaster 24 bit audio card , fed from rig data out ** Why this is so, may be due to filter ageing ? IC7100 FT897D { 10 years old ]
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Graham
KEY To CARRIER delay accommodation
Running on a somewhat traditional set up com port ptt Tx path :: Exciter >> Linear Amp >> Ae change over relay where the Linera tx line / is addressed from the secondary contacts on the Ae relay , the measured Tx to on-air carrier delay is 52 mS , ptt enable > Rf wondering if this was too long [ days of amtor ] Apparently the Vara HF modem can accommodate up to 120 mS delay may/may not affect stations using tx/rx sequencing 73-Graham g0nbd
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