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Radio engineering doesn't mesh well with a "move fast and break things" world view. Often the things you're breaking mean other people are losing out. The worl
by giantrobot 5y ago
Radio engineering doesn't mesh well with a "move fast and break things" world view. Often the things you're breaking mean other people are losing out.
The world of HF is very different from higher bands because of propagation and low band width (especially for hams). With a well tuned antenna even a relatively modest transmitter can DX hundreds or thousands of miles.
* The low band width on HF with a high noise floor makes high symbol rates pointless throughout the band. You'd need so much FEC there'd be little benefit from the higher rates. A symbol rate that might work fine for contacts a hundred miles apart will just be noise for contacts five hundred miles away. Because of DXing on HF it's entirely possible to have your transmissions picked up across the hemisphere.
* Likewise symbol rate negotiation is problematic because of propagation. Transmissions aren't point to point links even if you're addressing a particular station. Like the point above symbol rates that work for two stations will not necessarily work for all stations that will receive the signal. That's just more noise for them and an inability to use that part of the band.
* The band width for hams on HF is too small for spread spectrum comms to be useful. Yet again transmissions that work in some conditions won't necessarily work everywhere the transmission reaches.
* Quick, what's the difference between an encrypted signal with a long duty cycle and noise? NOTHING. Every aspect of ham radio comes back down to being good stewards of a scarce resource and sharing it.
If you blast your headphones you're not going to affect me living next door. You can listen to whatever you want at any volume. If you blow out your ear drums that's your business. If you instead blast your big-ass stereo speakers now you're affecting me next door. You've got a right to blast out your eardrums, not mine.
Radio, like the air between our houses, is a shared medium. There's bands where if you want to blast signals or play around with different modes, I'll never detect it even living next door. There's also bands, like HF, where you can affect my use of the band even on opposite sides of the state. You don't have more of a right to hams bands than I do. If you want to blast high powered wide bandwidth transmissions, petition the FCC to buy a license to some spectrum (good luck).
The issue isn't graybeard hams being afraid of new fangled technology. While those do exist the much bigger issue is the whole of the HF band (and all uses of it) could fit in a single WiFi channel with room to spare. Of that tiny space hams have privileges on a tiny subsection. To even use that tiny subsection requires advanced licensing and a fair investment in equipment. Any individual user wants to put that time/money investment to use but so does every other user. It's hard to share a sliver of bandwidth if there's a couple assholes essentially blasting out noise all across that sliver of spectrum.
- edrxty 5y agoMy arguments tend to sum to the fact that the ham radio bands are provided as an experimental space. I'm not advocating for anything that hasn't been tried before, in particular encryption is legal in other countries and hasn't caused any issues for them.
- giantrobot 5y agoWhile I'm sure you've got links to regulations allowing for hams to use encryption, they're going to fall into two categories: emergency communications and preventing unauthorized access to remote automated stations (satellites etc). So encryption doesn't cause problems because it's scope is extremely limited. As for your suggestions for things in the HF bands, they simply do not make sense for the reasons I described. In the blasting stereo analogy, HF is like a stereo blasting you can hear across the country. There's very little bandwidth to even negotiate between stations and conditions vary so much that you'd need to change the symbol rate constantly. Hams settled on CW and slow digital modes on HF because that's what tends to works best on HF. They don't need wide bandwidth and they resist multipath interference.