[aprssig] New VARA-HF Softmodem A Spectacular Improvement For HF APRS

Jess Haas k5lli at jesshaas.com
Mon Jan 9 08:59:10 EST 2023

That is great news. Sadly I feel like the proprietary windows only nature
of a lot of these modes is why they never really take off as much as they

With modes that have an open source implementation it can be much easier to
properly setup igates as well as have reassurance that it will be properly
maintained and able to run on modern hardware well into the future. If APRS
had used a proprietary encoding from the start it never would have taken
off the way it has.


On Mon, Jan 9, 2023, 6:19 AM Stephen H Smith via aprssig <
aprssig at lists.tapr.org> wrote:

> After spending nearly the entire New Year's 3-day weekend twiddling TCP/IP
> settijngs, serial port emulators, sound card drivers, etc,   I now have the
> VARA high-performance HF soft-modem working with the UIview and APRSpoint
> APRS programs.
> I am using a stack of components from "VSPE" (Virtual Serial Ports
> Emulator) to create a serial-to-TCPIP bridge to connect the serial-only
> KISS output of UIview to the network (TCP/IP) KISS connection provided in
> the VARA soft-modem.
> For nearly 40 years, HF APRS has used classic 300-baud 200-Hz-shift HF
> packet (mostly on 30 meters) as it's transmission method. However, packet
> is a horrible mode on HF with poor immunity to noise and HF selective
> fading.  I've been using the "UZ7HO Soundmodem" soundcard "soft TNC"
> (arguably the best HF packet TNC - hardware or software) for this purpose.
> However, it still falls far short of modes like MFSK16 or PSK63 for
> weak-signal data operation.
> For about two years, I have been experimenting with using FLdigi as a KISS
> modem for HF APRS on both 30 and 60 meters.  60 meters tends to be a noisy
> band, putting a premium on data modes that can perform error-free at low
> signal-to-noise ratios.  My web site about this is here:
>     <http://WA8LMF.net/FLdigiAPRS> <http://WA8LMF.net/FLdigiAPRS>
> Over the weekend of the 6th and 7th of January , I conducted a road test
> comparing the performance of APRS over traditional HF 300-baud AX.25
> packet  vs  APRS using the VARA modem on 60 meters.  This was a 500-mile
> round-trip from central Michigan (East Lansing area) to west suburban
> Chicago and back.  VARA was overwhelmingly superior - by least an order of
> magnitude!
> The full details, including a brief background on VARA,  are on a new page
> on my web site at:
>     <http://WA8LMF.net/APRS_VARA> <http://WA8LMF.net/APRS_VARA>
> ------------------------------
> Stephen H. Smith    wa8lmf (at) aol.com
> Skype:        WA8LMF
> EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
> Home Page:          http://wa8lmf.net
> -- APRS over FLdigi Modes  --
>    <http://wa8lmf.net//FLdigiAPRS/index.htm>
> <http://wa8lmf.net//FLdigiAPRS/index.htm>
> 60-Meter APRS!   HF NVIS APRS Igate Now Operating
>    <http://wa8lmf.ddns.net:14447/> <http://wa8lmf.ddns.net:14447/>
> Flying Digipeater!
>    <http://WA8LMF.net/FlyingDigi> <http://WA8LMF.net/FlyingDigi>
> 11 Copies of UIview in Action on One Computer!
> Live Off-The-Air APRS Activity Maps
>    <http://wa8lmf.net/map> <http://wa8lmf.net/map>
> _______________________________________________
> aprssig mailing list
> aprssig at lists.tapr.org
> http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org
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