The FCC is circulating a proposal for new rules pertaining to amateur radio in the United States. In particular, they want to remove certain baud rate restrictions that have been in place since 1980. It appears the relaxed rules would apply only to some bands, notably some VHF and UHF bands along with the 630 meter and 2200 meter bands, which — we think — are lightly used so far. We’ll save you from grabbing the calculator. That’s around 475 kHz and 136 kHz.
Ham radio operators have long used digital modes like radio teletype and with restrictions on antennas and increasing interference from wireless networking to solar panels and more, digital has become even more popular than in the past. Besides that, cheap computer soundcards make it easier than ever and sophisticated digital modulation techniques have long left the old, clunky TeleType in the dust.
However, the FCC currently limits the baud rate to 300 baud or less, ostensibly to restrict signal bandwidth. No one wants to have an entire band consumed by a 10 Gb RF network. However, modern techniques often squeeze more into less and the FCC will finally recognize that by converting the limit to signal bandwidth, not baud rate.
What’s the bandwidth? For the common bands, it sounds like 2.8 kHz is the answer. For the VLF bands, they are asking for suggestions. The 2200 meter band isn’t even 2.8 kHz wide to start with!
All this talk makes us want to build something for the 2200 meter band. We better start winding the coil now. Then again, maybe we should go piezo. You know, just in case Thomas Dolby tells us that one of our submarines is missing.
That new ~3 KHz channel limitation of the SSB era wasn’t very wise to begin with.
Back in the AM days, ~5 KHz were being used (carrier+two side bands).
Rather than reducing the channel bandwidth, it would have been more appropriate to use these ~5 KHz for SSB.
So a single side band would make use of those ~5 KHz to improve audio quality.
Because, actual information of human speech lies within the higher frequencies.
Especially with women and children being affected here.
The reason we can still decipher things is because of the “error correction” of the human brain. For native English speakers, at least.
Foreign radio buddies may have trouble here, because of extreme lo-fi quality on shortwave.
Alas, the individuals in charge of those regulations were older men and either didn’t care or didn’t know. But that’s another story.
It’s just puzzles me why quantity always wins over quality for apparently no good reason.
The ham bands are being more and more abandoned, anyway. Why must channel spacing be reduced over and over again ? Unused repeaters are being enough there, already.
On 2m/70cm, the 12,5 KHz channel spacing did more harm than good.
The old 25 KHz channel spacing allowed for more bandwidth, less interference and better signal/noise ratio.
On the road, a broader FM signal is lesser prone to the doppler-effect, too.
PS: Let’s don’t forget that certain things on the band plan have the nature of a recommendation.
Amateur radio is an experimental service, too.
Limiting it artificially wasn’t the idea, originally.
As long as amateurs don’t cause interference, a deviation from the norm should be possible here and now.
Personally, I think an adequate title for this would have been “too little, to late”.
Just recently your FCC had permitted the use of FM on the 11m band, which was overdue.
https://landline.media/fm-is-coming-to-a-cb-radio-near-you/
Here in Europe (Germany), we had been allowed to use FM since 1978.
SSB had followed in 2011, I believe, which was rather late.
So please don’t get me wrong, it’s nice to see that the FCC finally catches up.
But it’s still very backwards compared to the rest of the world.
This is just another attempt to get the changes tabled in 2016 pushed through. It’s wrapped in language to make it sound like it’s to the benefit of all of amateur radio, but it’s really to allow WinLink to use more amateur radio spectrum.
Yep… Wall to wall W2K/VARA/P4
Not if the bandwidth stays the same, I can spend 4 hours transmitting a message or 4 min
Well, when those protocols were adopted in 1980, the internet, most of the large ISP’s of the time, and even D-Dial didn’t exist. Nowadays, with robust networks, and the technical innovations of the last 40 years, it’s definitely time to update the protocols. When D-Dial first came on the scene back in 1984, Schools still used Apple ][ computers in the classroom. When Bill Basham wrote D-Ddial, it was because a nurse lamented to him about the price of the hourly rates the big services like Compuserve and GEnie were charging at the time. AOL came into being and got the internet more exposure. Now with large ISP’s like Comcast, TCP/IP has long surpassed 300 baud-56k. If D-Dial were to run over radio, you would need 7 full duplex connections.
It’s doable from an experimental point of view, but not practical even with modern radio equipment.
For those wondering what D-Dial is, you can check out magviz.ca or ddial.com.
With the multi-gigabit connections we have, and the size of some video game downloads, there’s no way we could have today’s internet with 300-56k. Ham radio on the other hand, we’re not transferring multi-gig files.
Any increase in speed means more efficient use of the spectrum we’re allocated. 30 characters per second for its time was considered fast compared to 110. 56k modems were pushing the limit of standard POTS technology. Imagine what hams could do if we could do 56k over radio. Instead of tying up a frequency downloading SSTV or WEFAX using our current protocols, the speed increases alone would make for a more efficient use of spectrum.
Thanks for the information, I didn’t know about D-Dial yet, for example. 🙂👍
Personally, I think that the old protocols aren’t that “harmful”, though.The hey’re not often anymore, anyway.
Contests are even worse by comparison, I believe, since they do nothing other than serving people’s egos. In fact, they constantly get into the way of social hams into real QSOs who only have a spare free-time on weekends.
The V.92/56k modems of the 90s were very interesting from the point of view of the DSP technology used. Unfortunately, the landline modems were severely limited by the quality of the landline, so only a fraction of the theoretical achievable data throughput was possible in practice. ISDN, by contrast, could really do 64k in practice. On the ham bands, what’s also hindering high-speed data transfer is the prohibition of compression. Pactor beyond PACTOR-I uses it, but its compression can’t be used on the ham bands so easily. If a compression technique was “open” (publicly readable to everyone), maybe it could improve things. But efficiency alone isn’t everything, maybe. Shortwave is very unreliable. Making the most out of the bandwidth may reduce the signal-to-noise ratio. That’s why RTTY had used such a big “shift” for long time.
If lots of error-correction is being required, the effective data rate goes down again, despite the high-speed connection. My apologies for my bad wording, I hope it’s still understandable what I mean to say.
The old protocols are still useful, and will probably still be used long after I’m taking a dirt nap.
It’s just nice to see that some things will be improved. Radio propagation and band conditions are the challenges that have to be overcome.. I used D-Dial as an example because it was the first one-to many real-time chat systems available. As I said above, today’s internet didn’t exist.
300 baud was the perfect speed because you were just reading the text that other people typed.
On a single station it was you, the system operator and 6 other people. When D-DIal’s linked and believe me, when multiple stations linked and you had 80-100 people on at a time, the backlog was legendary. I do like listening to shortwave, and depending on conditions, WWV will fade in and out from time to time. Our brains are quite good at filling in missing information, like when copying CW, you may miss a letter or two due to fading etc. but your brain fills in the missing information. I did an experiment with another ham, we were right next to each other, and I sent a small picture over radio to a D-STAR repeater that he received via his radio. The picture was a jpg which as you know is compressed. I’m a bit fuzzy on the rules, but I think it’s encryption that can’t be used on the ham bands except in certain command and control applications. Still though, faster speed means less time on the air transmitting a picture etc. This means that more hams could use the bands and things wouldn’t be as crowded as they are. At 30 characters per second, you could miss a few and still know what the message is. Going faster, you miss more of the message and may have trouble deciphering its meaning. My example of SSTV and WEFAX illustrates this.
I’ve received SSTV and WEFAX that were not perfect, but that’s the nature of radio.
” I do like listening to shortwave, and depending on conditions, WWV will fade in and out from time to time. Our brains are quite good at filling in missing information, like when copying CW, you may miss a letter or two due to fading etc. but your brain fills in the missing information. ”
I like listening, too! 😃 I started as an SWL since when I was little (my father had an 101 boat anchor).
Understanding others in telephony mode wasn’t always easy, though. To me, understanding English people under bad condition was worse than understanding my fellow countrymen. There was a lot of guessing of my brain involved, so to say. If the audio quality on shortwave was a bit higher, if the higher frequencies of human speech were being properly transmitted, as well, deciphering would have been easier. In my opinion, at least. I think that may also apply to Mexican or Japanese hams who try to talk to an English/American ham under such tricky band conditions. Telegraphy is less affected, likely, since it’s an universal language using “same accent”.
” the speed increases alone would make for a more efficient use of spectrum.”
Yes but No….. What will occur is the W2K emails will get MUCH LARGER.
We will go from 1 or 2k emails to 100k+++. In 5 years from now the
“digital/CW” parts of the bands will be nothing but W2K email servers.
That’s plausible, yes. I think the basic idea was that the channels are not so long in use by each user. Provided, that the information doesn’t increase.
Just like IBM had assumed that DOS 4 with PC having 640KB RAM would be no worse than DOS 3 with PCs having 512 KB RAM.
In reality, DOS users already utilized those 640 KB on their PCs runnung DOS 3.
Ok, another example.
Pactor-I is slow, but also quite robust. Exactly because it’s slow and primitive.
The bursts are nicely timed (not too slow, not too fast), too, so fading does rarely interrupt it.
On the other hand, other digital modes much quicker than this may loose a lot of data packets under bad conditions.
In that case, if there is no FEC, the whole block must be re-sent.
If that happens a lot, the overall communication will be slower than Pactor-I, SITOR/AMTOR or plain RTTY.
That’s why 300 Baud Packet-Radio is so bad for shortwave.
One bit that gets flipped and everything must be re-sent.
That’s why FX-25 and other additions were being developed. If only hams would upgrade here. At least on the digipeater side of things. Ideally, old TNC firmware’s would be disassembled and manually updated using assembly language. In case of FX-25, it would be a minor hack to do (use FEC data).
What. May be more important is legislation to extend PRB-1 to private land use agreements. In 2017, HR555 passed the House and had an identically QQ worded senate Bill reported out of committee. It died because the Senate Majority Leader refused to put it to a vote.
Many on HF DO use FX.25 – I have for years. KT4WO-6:LAZY 7.104LSB
Both UZ7HO and DireWOLF support FX.25
As for the other post…re HOA’s —- Hard to feel bad for someone who
buys in a HOA. :( But— I kinda do.
We have had 56k rf modems for ham radio since since 1980. The just never picked up steam. You can still get one, and with the rule change they should become important.