Topics

Whats new in VARA 4 ? #VARA #qrp


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



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 ]


Graham
 
Edited

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


Tomasz
 

Thank you for the quick reply !
I will look for a solution.

73 Tomek
SP5LOT


Andrew OBrien
 

if you are using paired virtual ports , try removing the paired ports and then re-create the pair 

Andy


On Jul 12, 2020, at 10:13 AM, Graham <g0nbd@...> wrote:

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


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


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


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


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


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


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




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,

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


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 . 

Andy
K3uk 

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


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 . 

Andy
K3uk 

On Jul 6, 2020, at 3:29 PM, Graham <g0nbd@...> wrote:

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 

 


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 

 


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 . 

Andy K3UK 


On Jul 5, 2020, at 5:51 PM, Andrew O'Brien via groups.io <andrewobrie@...> wrote:


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:

[Edited Message Follows]

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 

<vspeed1.png>




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 


<vspeed2.png>



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



--
Andy


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:

[Edited Message Follows]

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



--
Andy


Graham
 
Edited

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