Understand that I have used MIL-STD-188-110a and FS-1052(?) modems (modes) when I was in the AF Reserve. I used MIL-STD-188-110a and c (I think) in February of 1990 in US Air Force test, then in California during joint services test in the summer of 1990 and while in Saudi in the fall of 1990. I don't think they are as robust as some of the amateur radio digital modes.
Yes, we've used MT63 VERY successfully and it meets 90% of our needs...the 2K Long Interleave is VERY robust...about as robust as we need. If we want a faster turn-around, we will go to short interleave and/or 1K short interleave.
The only problem is that the throughput is lower than we need. MT63 2K Long Interleave seems to have a SNR of less than 0 dB on a CCIR Channel (probably between -5 and -7 DB SNR) and the throughput is 200 WPM...we would like to see 400-600 WPM or at least 300-400 WPM.
We aren't concerned about band width. Even if the ARRL proposes 3.5 KHz max band width, I think that another proposal going to 6 or 8 KHz for OFDM type modes would be acceptable to the FCC as this is "good physics/good electronic engineering" and in keeping with good amateur radio practices.
<Personal Opinion>
If the FCC says NO to a wider bandwidth, then the choice may be to go to Congress pointing out how the FCC is prohibiting technical research/ experimenting and advancements in communications technology as Part 97 says amateur radio operators should and ask Congress to review the matter. The only reason I say this is that I have talked to three Republican Congressmen and two Democratic Congressmen and they agree that if nothing else besides providing support/auxiliary communications during an "Incident" or disaster, hams should be experimenting and should have the opportunity to experiment within the ham bands to the maximum extent possible in developing communications techniques...even if they are not directly applicable to commercial or government communications.
</Personal Opinion>
73,
Walt/K5YFW
-----Original Message-----
From: digitalradio@yahoogroups.com
[mailto:digitalradio@yahoogroups.com]On Behalf Of KV9U
Sent: Tuesday, March 14, 2006 10:55 PM
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] Re: Another look at ALE
Walt,
What you are describing sounds very close to MT-63.
73,
Rick, KV9U
DuBose Walt Civ AETC CONS/LGCA wrote:
>There has been some discussion about what mode does what and what is
>needed/desired.
>
>We have had a little discussion on what the problems were during Katrina
>with digital communications.
>
>During hurricanes Katrina and Rita, I worked with a disaster relief group
>and operated as their HF net control station and a participating station.
>Our network in Katrina ran from the Mississippi Gulf Coast up to Atlanta
>back to Louisiana including New Orleans, Batron Rouge, Hammons, Bogalusa and
>north, Alexandria, Lafayette, Beaumont Texas, Dallas and San Antonio Texas.
>
>Most of the time we would have liked to use a keyboard-to-keyboard
>mode...probably 60% of the time. 20% to 30% of the time Sideband Voice was
>Ok. But there was 10% of the time when we would have liked to be able to
>send a rather large data file from our Dallas, San Antonio or Atlanta
>stations to all of our stations. In many instances conditions were so poor
>that voice communications didn't work very well at all. Most of the time
>when sending smaller data packages, reading them by voice worked Ok;
>however, we have many request for repeats and we had to relay many times.
>
>We only operated on three frequencies and primarily on 40 and 75 meters
>since propagation programs showed that these were the best frequencies to
>use at the time.
>
>I might mention that our net operations and net control stations operate
>much like a state or local EOC (I worked many years in a large city EOC).
>
>When I think of what I would like in a mode to support the type of
>communications I was involved in (and I think most of the disaster relief
>agencies such as the Red Cross, Salvation Army and the like), I would like a
>robust keyboard-to-keyboard mode that would accept typing at about 50-60
>WPM. Also a robust mode that could send data files at 200 WPM and be robust
>enough to work right down in the noise.
>
>As far as frequency selection, when you only have 2 bands that will support
>propagation and use only one frequency on each band, channel selection is
>not a problem. An automatic call ability, such as SELCALL, would be very
>nice to have.
>
>Most of the other capabilities I hear about are nice but not really needed.
>
>I believe that the type of operations I was involved in, and will be again
>this hurricane season, are useful in passing many if not most types of
>traffic on HF.
>
>Thanks and 73,
>
>Walt/K5YFW
>
>
>
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