Winlink Digital Mode Performance Comparisons

[AA3JY]

https://www.winlink.org/sites/defaul...y_5_2020_0.pdf

[ka4wja]

Clay,
Thanks for posting this!

I learned something here....(and was surprised by the poor showing of Winmor1600).

FYI, for those curious, have a look...as even PACTOR 2 (a 500hz bandwidth mode) outperforms Winmor1600, at all S/N's of 15db or less...


{Btw, as many of you know, I've always thought having email connectivity while at sea / on passage (and/or in remote areas) to be well over emphasized as "necessary" or "important" (I don't think it's necessary at all, but that's just my personal opinion...)
And, I've never been a fan of PACTOR modems, as I've often thought they were too high priced....
But, not surprising to most, I have always appreciated the elegance of SCS / PACTOR (especially PACTOR 3, and more recently PACTOR 4), and have always recommended Sailmail over Winlink (for their station reliability and system/station design, as well as their use of PACTOR 3 and 4)...
And, hence have begrudgingly recommended a PACTOR modem a few times, to those who have expressed a need for email connectivity while at sea or in remote locales...}


https://www.winlink.org/sites/defaul...y_5_2020_0.pdf


So, while I'm still not sure that many actually need email connectivity at sea, the above performance tests confirm the advantage of Sailmail and PACTOR 3 and 4!



Thanks again for posting this.

John

[Pitchondesign]

Interestingly, the VARA performance was very close to Pactor 3 and only slightly behind Pactor 4. I couldn't find which version of VARA was being tested. There is a newer version of VARA 4.02 which just rolled out on June 30, replacing the V3xx series. The V4 promises better weak signal performance. Given the vast cost difference between VARA and Pactor, and shrinking performance difference, VARA wpuld seem to be a no brainer.

I do have a need for email at sea. It is to get grib files from SailDoc, twice a day, when out of cell range.

[ka4wja]

Pitchondesign,
I do understand the need for weather info/forecasts....

Originally Posted by Pitchondesign

I do have a need for email at sea. It is to get grib files from SailDoc, twice a day, when out of cell range.

What I do find somewhat confusing is that some decide on GRIB's (the raw computer model data) rather than the synoptic charts / WeFax charts (drawn by experienced maritime meteorologists)?
Along with the added requirement of "sending for" and "downloading" these GRIB charts (via email), versus the free HF broadcasts of synoptic charts...
(and the costs of software/modem/interfaces, and any subscriptions, etc.)

For most offshore sailing, which I started doing decades ago (my first cruising was as a kid in the 1960's, Bahamas and Caribbean....and then 10 years later, across the Atlantic and few seasons in the Med, etc....followed by more Atlantic crossings and more cruising thru the Caribbean and Bahamas)....most sailors will find HF WeFax charts (updated 4 times a day) to be the Gold Standard of offshore weather....
And, of course, these require no email connectivity, no modem, no subscriptions, etc....

No worries though, we all have our desires and make our own choices....
So, no big deal here...
And, no more ramblings from me today, on this....

Fair winds.

John

[Pitchondesign]

I agree, the Wx Fax broadcasts are valuable, and I do use them. For me, the gribs add data to be used in conjunction with the Wx Fax broadcasts. For me, one is not better than the other, just more data to be used in the decision process.

[Coquina]

If only there was a Linux version of this stuff Is there? So far all I have found is using VARA with Wine.

[Pitchondesign]

Originally Posted by Coquina

If only there was a Linux version of this stuff Is there? So far all I have found is using VARA with Wine.

According to the winlink site, Rms Express works on Wine. I haven't tried it myself, so only passing on information.

Here is the link:
http://k6eta.com/linux/installing-rm...inux-with-wine

[Coquina]

I guess it was too much to expect WIN-link to work on anything but Windows

[Shawanaga]

After a 40 year career in IT, I'm amazed at how the HAM radio community seems mostly oblivious to the virtues of open source software and unencumbered (patent-free) open standards for modulation schemes etc. There are are few exceptions, like Joe Taylor and WSJT-X.

But many hams seem to be happy distributing EXEs that run only on Windows and keeping the source code private . No idea why. Can anyone explain to me the logic of this?

[AA3JY]

For those with PACTOR 4 capability and assisting with ECOMM..

FCC Grants 30-Day Waiver of Rule 97.307(f) for Hurricane Laura Recovery
The FCC has granted an ARRL request for a 30-day waiver to facilitate relief communications in the wake of Hurricane Laura. The waiver temporarily permits amateur data transmissions at a higher symbol rate than currently permitted under the FCC’s rules. ARRL pointed out in its request that Amateur Radio Emergency Service (ARES) members would be working with federal, state, and local emergency management officials to assist with disaster relief and may use radio modems capable of both PACTOR 3 and PACTOR 4 emissions. The higher data rates PACTOR 4 offers are critical to sending hurricane relief communications, including lists of needed and distributed supplies.

Section 97.307(f) limits the symbol rate — also known as the baud rate — for HF amateur radioteletype (RTTY) and data transmissions to 300 bauds for frequencies below 28 MHz (except on 60 meters), and 1200 bauds in the 10 meter band. “The digital code used to encode the signal being transmitted must be one of the codes specified in section 97.309(a) of the Commission’s rules, but an amateur station transmitting a RTTY or data emission using one of the specified digital codes may use any technique whose technical characteristics have been publicly documented, such as CLOVER, G-TOR, or PACTOR,” the FCC pointed out in granting the request