VARA and Winlink


Paul Butzi (W7PFB)
 

Motivated by the Weekly Net check-in via Winlink I have been experimenting with Winlink again.

In particular I was interested in what changes happen as a result of the abandoning of the Winmor connection protocol/modem/soft TNC.

The direct replacement for Winmor is ARDOP. I have used ARDOP for a while, it is more reliable and perhaps a bit faster than Winmor but not a dramatic improvement.

So I decided to try VARA.

The downside of VARA is that if you want it to go into fast mode, and you want to avoid the nag screen, you must buy a license, which costs $70.

The upsides are:

* VARA is faster, especially in good conditions when you can run a fair bit of power on your end (most of the Winlink RMS stations seem to run pretty solid signals). On a really solid connection, VARA is massively faster.

* In any conditions that are less than ideal VARA is dramatically more reliable and faster than any of the non PACTOR alternatives. As PACTOR TNC’s cost more than $1k, that makes $70 a pretty good deal. (I don’t own a PACTOR TNC so I don’t know how the various PACTOR modes stack up against VARA)

In short I can connect to more Winlink RMS stations using VARA than I can using Winmor or ARDOP. I can connect more reliably when conditions are not optimal. I can connect reliably using 5-15W instead of 30-70W. And the connections are faster.

In short, I think it’s a pretty interesting piece of technology.

And that’s all on HF.

There’s a version of VARA for VHF/UHF FM which can exploit the wider audio bandwidth you get when you use the 9600 baud receive data path of a VHF/UHF radio that offers input/output for a 9600 baud packet modem.

This would get around the big problem with VHF/UHF Winlink, which is that packet radio is deadly slow. The slow speed of packet is the flaw that makes VHF/UHF Winlink nearly useless for tactical use in an emergency. There are other problems with VHF/UHF Winlink but the flaw that cannot be ignored is that it is just too darn slow for modern needs like moving digital photos or larger files.

I’l be ordering some hardware to allow me to exploit the wider data path you get using the 9600 baud audio path - basically a couple of wide bandwidth sound cards.

Is anyone else interested in experimenting with experimenting with VARA on VHF/UHF FM? If so, let me know and we can coordinate.

Also, if you’re a Winlink HF user, I urge you to check out VARA. The evaluation copy, speed throttled as it is, is still a dramatic improvement over Winmor and ARDOP, especially in marginal conditions.






-p W7PFB
73, Don’t forget to smile and have fun!

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