[-] VE3MAL@lemmy.radio 2 points 11 months ago

On HF, unfortunately, physics is going to keep you from having high speed data. The Shannon–Hartley theorem puts a ceiling on the maximum bitrate of a channel in the presence of noise. If you are on HF with your 100w transceiver and a dipole antenna, your signals are always going to be weak enough on the other end of a skywave contact to limit your data throughput. Even given a magical ham prodigy that invents the best mode imaginable, it's going to be Kbps, not Mbps. If you want to learn about the development of open source, higher throughput digital modes for HF, I highly recommend David Rowe's blog on the development of FreeDV over the years. There's even a recent move to general data in addition to digital voice. However, we are talking about single digit Kbps digital. There are some other modems used by the Winlink folk that are a little higher. The drop of the baudrate limit will just remove an artificial contraint, and headache, on that development.

On line-of-sight VHF and up connections, it gets easier and easier as you have higher gain antennas pointed at each other and lower natural noise figures.

[-] VE3MAL@lemmy.radio 1 points 11 months ago

Bandwidth doesn't put a hard limit on bitrate either. It's one variable, but there's also SNR (See Shannon). With a fixed bandwidth, you can have low bitrate and excellent low-SNR performance (think of Olivia), or you can have higher bitrates, and require stronger signals. For practical purposes though, you are not going to get highspeed internet on HF. But that's what sharing is like. 🤷‍♂️

[-] VE3MAL@lemmy.radio 4 points 1 year ago

It's a neat idea, but could be implemented entirely in software with a RTLSDR. Not my cup of tea, but I'm all for absolutely ANYTHING that gets more activity on V/UHF.

A longer term project goal for me would be a SBC and a couple RTLSDRs with a good antenna that simultaneously does APRS igating, streaming audio of all the local repeaters and a few simplex channels, and notifications like this project, and like the "adventure radio" project that uses CTCSS tones to trigger alerts. I think it would be a nice service to provide for locals. The only "trick" is that RTLSDRs can only simultaneously decode within a 2.5mhz window, so it would probably require a little scanning to cover everything, or too many sticks. Doing a project cheaply, but effectively, encourages copy-cats.

[-] VE3MAL@lemmy.radio 3 points 1 year ago* (last edited 1 year ago)

50 meters is enough for a 80m 1/2w dipole. And yes, google a "fan dipole" - you can hang multiple dipoles below each other with as little as a few inches of separation. However, the dipoles interact with each other, and getting it right gets more troublesome the more you do.

[-] VE3MAL@lemmy.radio 2 points 1 year ago

God the Klingon thing was silly. Do we need an explanation as to why the TOS ship had plastic, 1960s themed furniture? Do we need an explanation for improved camera resolution over the years? Why did we need a silly explanation for the improvement in makeup artistry so many decades later? And the explanation doesn't even work. Genetics don't work like that. It's taking themselves too seriously. Either ignore it, or hang a lantern on it with an inside joke once, and be done with it.

[-] VE3MAL@lemmy.radio 3 points 1 year ago

It mirrored the contemporary idea of the "End of History", where all the existational crises were done with, the federation (was basically moving into a time of refinement rather than having to worry that the experiment might still utterly and completely fail. TNG was basically one long, slow lesson of why that was a flawed notion. You don't build a cruise liner, fill it with families, and then intentionally send it into the kind of peril that regularly befitted the Enterprise D. In retrospect, it was completely ridiculous.

[-] VE3MAL@lemmy.radio 5 points 1 year ago

fyi, nearly everyone that succeeds in achieving morse proficiency recommend strongly against any sort of visual cues like this. It's an auditory "language" and adding visual interpretation steps just adds cognitive load and hurts in the long run. It may be fine if your goal is to learn max 5 words per minute or something extremely slow.

[-] VE3MAL@lemmy.radio 6 points 1 year ago

Yes. This is a setting in the menu. Audio source is selectable separately for -D and non-D, so one of them can use the mic and one can use the aux, or whatever you want. I believe it also recalls the various DSP settings as well, so you can set things up how you like for phone, and for digi and easily toggle back and forth.

It's not about a pre-set per-se, but about having 2 custom U/LSB profiles.

[-] VE3MAL@lemmy.radio 2 points 1 year ago

There's negligible advantage in loss going from pl259 to N connectors on HF. You don't have the kind of losses you do on VHF and especially UHF. The only time N is really nice is when you need an intrinsically weatherproof connector -but this is mounted inside the weatherproof box.

If you want slightly better loss specs AND a more convenient, quicker connector, BNC is great. But PL259, as I said, is fine.

[-] VE3MAL@lemmy.radio 3 points 1 year ago

Star Trek discussion /usually/ tends toward anything new being bad, and always has. SNW and lower decks are exceptions because they do so much fan service and return to a more classic Trek format. Discovery was groundbreaking in a way that I'm sure Roddenberry would have enjoyed, but groundbreaking also implies jarring change and throwing away things that work for experiments that sometimes don't.

[-] VE3MAL@lemmy.radio 2 points 1 year ago

Congrats, and careful with that mod. I purchased a used 7300 a while back that someone did a terrible wideband mod and antenna tuner mod.

[-] VE3MAL@lemmy.radio 3 points 1 year ago

I've played around with this before, and it does indeed seem to work quite well via audio coupling, which makes me think it's probably a little more robust than typical packet. Glad to see the various new digital modes being developed for on FM. Some people just have an HT and need more toys to play with than just APRS.

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VE3MAL

joined 1 year ago