Jason - VE3MAL

  • 0 Posts
  • 36 Comments
Joined 1 year ago
cake
Cake day: July 11th, 2023

help-circle
  • 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.


  • 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. 🤷‍♂️


  • 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.





  • 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.


  • 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.


  • That’s basically what shortwave pirates are. Usually former ham transceivers modified to transmit out of band. The cost of licensing and building a shortwave broadcast station are immense. And there’s the pesky problem of finding advertisers when the license scheme basically requires you to at least look like you are targeting non-domestic audiences. Hams have occasionally purchased time on existing transmitters when it’s cheap, but as far as “experimental modes” go, it would typically have to be something that can be modulated by an AM transmitter.






  • That manual is written by Jordan, but the key point is not the manual, it’s the software and protocol.

    JS8Call has a few bits it can devote to “special” group calls that save a lot of bandwidth, and saving bandwidth improves how much you can send in a single cycle, improving both communication speed AND fidelity. But there are only a few of them because they are limited by the protocol design, so Jordan necessarily has to be selective. He chose to devote one of those to a group with christofascist and insurrection ties. That is an implied endorsement, or special assistance rendered to that group that turns off a LOT of hams. It’s quite literally baked in to the software. If that doesn’t bother you, fine, but I hope you can see why many of us would rather just stay clear of something like that.

    The relaying is also a problem. Though most people don’t automatically relay, it’s worth being aware that if you turn that feature on, you could be carrying water for AMRRON. It could also be illegal at a point. Without the network features of JS8Call, it doesn’t actually bring a while lot of fancy features beyond existing digimodes.



  • Amateur radios are generally spec’d at 13.8v plus or minus either 10% or 15% so that they work on a non-running car (12.something volts) or if an alternator is running a bit hot. A 100W radio like this is pretty much always going to require around 20amps at full power -but they have adjustable transmit power. They don’t transmit as well at the lower voltage range, but most people don’t worry about it.



  • 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.