[aprssig] APRS Igates Over VARA Mode Now Operating on 30 & 60 Meters

[Stephen H Smith]

The world's first Tri-Mode APRS igates are now "open for business" 24/7 on both 
30 and 60 meters....

The WA8LMF UI-Webservers now receive and igate APRS over classic 300-baud 
AX.25HF packet,  APRS over MFSK16 & PSK31,  and *now APRS over VARA* on both 30 
meters and 60 meters from my home station located in central Michigan.


VARA is one of the newest sound-card "digi-modes".  Written by Jose Ros EA5HVK, 
It can receive and decode error-free data transmissions at signal levels and 
S/Ns that literally can not be heard in the radio speaker.   With stronger 
signals, it can exceed the net data rate of VHF/FM 1200-baud packet in a 500 Hz 
CW bandwidth on HF !  VARA is adaptive, adjusting it's transmit speed up and 
down based on error rate and S/N., switching from simple to more complex 
multi-tone QPSK wave forms, based on error rate and the bandwidth of the radio.

In a 2300 Hz SSB bandwidth, it can exceed the throughput of 9600-baud VHF/UHF 
packet on HF.  It is already starting to replace the pricey (USD $600) SCS 
Pactor4 modems on Winlink HF radio email systems, purely in software with a 
standard soundcard interface.  The basic version, usable on the low data rates 
of APRS, is free.  A USD $70 registration unlocks the higher-speed modes.

Currently, the other widely-used activity, layered on top of the VARA 
"softmodem" is "VarAC Chat",  a live keyboard-to-keyboard chat application that 
can also do file transfers and "igate" received beacons to the PSK Reporter 
network. Running on top of VARA, it can equal the weak-signal performance of 
FT-8, but with free-form conversations instead of the  hello--sig 
report--goodbye  canned exchanges of FT-8.

VARA presents a KISS-over-IP interface to external programs. In principle, any 
application that can run over classic packet TNCs (messaging systems, BBS 
systems, APRS, etc) can run over a VARA link instead,  with an ENORMOUS 
increase (15-20 dB advantage) in weak-signal capabilities.  I have been testing 
APRS-over-VARA for over a year now. Some of my findings early this year are 
summarized on my web site at:

<http://WA8LMF.net/APRS_VARA/index.htm>   This was a competitive "shoot out" 
between classic 300-baud HF packet and VARA on 60 meters, on a 500-mile road trip.

At least three APRS client applications (PinPoint, APRSis-32 and YAAC) can link 
directly to a KISS-over-IP interface.  For older APRS clients, like UIview, 
that can only do KISS over a serial port, the third-party "Swiss-Army-Knife" of 
com port utilities "VSPE" can quickly and easily create an  
IP<-->Serial-Com-Port  bridge.  Full details on setting up VARA for use with 
APRS applications is here on my web site:

<http://WA8LMF.net/VARAforAPRS>

-------------------------------------------------------------------------------
Stephen H. Smith wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page: http://wa8lmf.net

"Studio B" Ham Shack on Wheels
<http://WA8LMF.net/Aliner>

-- APRS over VARA  --
<http://wa8lmf.net/VARAforAPRS.htm>

60-Meter APRS!   HF NVIS APRS Igate Now Operating
<http://WA8LMF.net/map/>

Flying Digipeater!
<http://WA8LMF.net/FlyingDigi>





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