WW4MSK--ARDOP & VARA connections increasing

Late March, I added the modes ARDOP & Vara to the frequencies my Trimode station WW4MSK polls. This was done to support the testing of those modes and to learn more about the strengths of ARDOP/Vara during this challenging time of poor propagation. March showed a few connections, then in April-May even more stations trying the new modes. The performance is tough to measure at this point due to the really bad propagation on some days and connection success rates were about the same as Winmor. Failure rates for sound card modes run around 10%-30% depending on conditions, time of day and frequency used. Pactor continues to have the best success with a consistent under 5% connection failure rate. These rates are calculated using the monthly ADIF log file for RMS Trimode which show bytes transmitted, connection time, last command and other metrics that are useful for determining success/fail.

I did try some local ARDOP & Vara connections to the nearby KK4NTE Trimode gateway and was able to see the performance for ARDOP/VARA approach Pactor III speeds. By purchasing a license for Vara, I was able to get even better performance for the local and distant connections tested. The cost of the license may seem high, but much lower cost than a Pactor modem. Without the license, the client side of the Vara connection is throttled. With a Vara license and good conditions seeing bytes per minute about 3000-6000 appears to be nominal. Higher speeds have been observed, but this varies quite a bit with band conditions. RMS Trimode Sysops do not need to purchase a Vara license to support the un-throttled performance on the gateways using Vara.

Below are the numbers by mode/month for Mar-May 2018. I'm sure we will see more growth as others try these digital modes.

Mar 2018 ARDOP-12, Vara-1, WINMOR-327, PACTOR-78
Apr 2018 ARDOP-75, Vara-15, WINMOR-244, PACTOR-97
May 2018 ARDOP-55, Vara-140, WINMOR-311, PACTOR-62

Time will tell how these new modes work out and other station reports will be great to see. It is encouraging to see others trying these new modes as it shows that our community is ready to experiment with alternatives to improve the speed/reliability of the Winlink service. There is some discussion within the maritime community and the forum at the link: http://www.cruisersforum.com/forums/f13/vara-compares-to-pactor-3-a-1998... has some personal performance numbers of one sailor using both Pactor & Vara.

Good luck with your testing of ARDOP & Vara!

Wally WW4MSK

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