I know next to nothing about radio, can someone tell me why a baud rate limit put in to begin with? Is there a technical reason for it like causing interference or something?
That's correct, more or less.
There's this thing called "frequency shift keying" (FSK) which was the de facto standard digital modulation technique at the time the regulations were created. With FSK, you transmit data by toggling back and forth between two frequencies. That abrupt jumping back-and-forth creates hellish interference for people trying to use nearby frequencies.
Today, the obvious solution is to limit bandwidth so that there's a healthy amount of space for people to avoid that interference. However, in a (1970s/1980s) world where FSK is the only widespread modulation scheme, that wasn't really the mindset. The way they saw it was simpler: "higher baudrates demand more bandwidth, and more bandwidth creates more interference." Thus, they regulated baudrate as a means of regulating bandwidth.
The impetus for the rule change is simple: we have better modulation techniques nowadays. In case I haven't bored you to death, the simplest one to explain is probably GFSK. It's similar to FSK, but instead of abruptly jumping between the two frequencies, you gradually slide back and forth between them (the "G" stands for Gaussian). GFSK requires more precise electronics, but it doesn't cause as much trouble for people trying to operate at nearby frequencies. There are countless other modulation techniques as well. Bluetooth is probably the most notable implementation of GFSK (though modern Bluetooth actually uses something else).
For completeness: FSK is very useful and it's still widely used today. Your garage door opener uses it, among other things.
However, amateur radio has some natural conservatism to it, like Morse code requirements (since retired) to gatekeep the hobby. Getting rid of this baud rate limit is long overdue as analog transmissions are laughably archaic for anything outside amateur radio.
The hobby already struggles with gatekeeping/driving off people who don't "ham right" and so making the hobby more accessible is a big positive in my book.
As long as you are Part 97 compliant, what exactly is your problem?
I mean the most basic CQ is dah dit dah dit - dah dah dit dah. You don't heard the dots or the dashes, you hear the rhythm. You don't see the CQ either, you know the concept from the rhythm as part of the conversation.
Btw, original American Morse had extra symbols!
I would understand perhaps semaphore because anyone can wave their arms about and communicate long distances.
But since radio requires equipment anyway, you might as well use modern digital equipment - with the benefit that in the same amount of time, power and bandwidth that a morse signal would use, you can send 10,000x more data.
Morse is the ultimate narrowband mode. The cleaner your oscillator and the narrower your output the better. On the receive side, you can make your receiver as narrow at the transmitters oscillator.
The only comparable digital mode is on-off keying which is used by cheap, low data rate devices. Even 'narrow' digital modes are wideband compared to morse code.
"On the receive side, you can make your receiver as narrow at the transmitters oscillator". Completely wrong, and shows a fundamental misunderstanding.
Morse is a wonderful mode, but suffers from the lack of error correction which had made modes like PSK31 and FT8 so much more effective, especially in bandwidth usage.
Clrly yu hve never usd this on the bands.
Yes, the error correction is between the operator ears. It is not a mode that can easily automated.
CW is wonderful, but is has long since been superseded by more modern digital modes.
You can easily use a transmitter with Gaussian keying to reduce the sidebands to zero.
The sidebands in CW ARE the information. If there were no sidebands, there would be no information.
> When the key is down there is no modulation whatsoever.
No, but you can't keep the key down forever. The information is in the transition from Key-down to Key-up (and Vice/versa). Which is why the modulation envelope (eg bandwidth) has to be tailored to the keying speed.
> You can easily use a transmitter with Gaussian keying to reduce the sidebands to zero.
Gausian keying requires a Raised-Cosine envelope. It is this which contains the sidebands and the information, and causes the B/W to be widened.
https://www.w8ji.com/cw_bandwidth_described.htm
and see "An Improved Audio-Frequency Bandpass Filter for Morse Code Reception" by James L. Tonne, W4ENE"
http://www.tonnesoftware.com/downloads/CWBPF-As-Submitted-To...
To understand this further, let's consider a more advanced modulation scheme. Instead of just having two states (high and low) to represent binary bits, imagine we have four distinct states: high, medium-high, medium-low, and low. These states can represent combinations of bits as follows: high = 11, medium-high = 10, medium-low = 01, and low = 00.
In this scenario, each state transition represents a symbol, and since each symbol can represent two bits, the symbol rate (or baud rate) is half of the bit rate. If you know the symbol rate and want to determine the bit rate, you'd multiply the symbol rate by the number of bits per symbol. In this example, you'd multiply the baud rate by two.
Most signals rely on techniques beyond simple voltage differences though to transfer information, and that's when you delve into the world of RF theory. Instead of a discrete voltage, a sine wave is used at a particular frequency. The amplitude of the sine wave can be adjusted just like we adjusted the voltage on that line. If we want even more symbols, maybe 0000 to 1111 or bigger, we can introduce another variation to the sine wave called phase. Phase of a sine wave is just shifting it left or right, but could be visualized as two people on a race track. If they start a race from the same line and run at the same speed in the same direction, they're in phase. If one of them starts a quarter of the way ahead from the other and they both run at the same speed in the same direction, then he's a quarter phase shifted from the other.
That adjustment of phase and amplitude falls into a broad category of RF modulation called QAM, and it's used in more than RF between two radios. It can also be used over Ethernet or PCIe busses.
I could go on rambling for a long time on all this, but hopefully this helps answer your question.
The FCC set the rules, not a bunch of old farts upset that the morse code test was eliminated. But because the FCC doesn’t pay much attention to the Part 97 service, it has taken them this long to get around to updating the rules.
This change was proffered as far back as 2008 at a Dayton TAPR session.
When these rules were adopted, a phone call to Europe was $3 per minute and a Telex as $10 for thirty words.
There are other restrictions like this. For instance, in my country, only clubs are allowed to transmit analog TV continously. Individuals can only make short transmissions.
Some people argue that increasing the bandwidth would incentivize digital modes. I can understand the point, but I would rather experiment with low-bandwidth modes than to take larger portions of the spectrum with faster, potentially wasteful modes.
EDIT: you should look at the shanon-Hartley limit. The bandwidth is proportional to the symbol rate.
This is not the case for classical frequency-shift amateur radioteletype. This sends two tones on single sideband, at 2125 Hz or 2295 Hz. So it uses up about 2.3KHz of bandwidth no matter how low the baud rate goes. 45.45 baud is classic mechanical Teletype speed, so the bandwidth is about 50x the data rate in that mode. You can do FSK up to maybe 600 baud; you need a few cycles to detect the tone frequency with classical filters. 300 is a traditional limit. Beyond that antique technology, you need a modulation scheme less than half a century old.
You equally could have used a narrower filter.
Before everything went digital, this sort of thing tended to involve a chain of analog processing stages.
Which of course meant two sets of sidebands (eg four in total) and a excessively wide signal..
But any of the better quality transmitters (Ham, Commercial or military) used pure FSK directly.