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Episode 2019-11 - Digital Communications

Hello and welcome to the next edition of the Mike Wills Podcast! This is the Dog Days of Podcasting edition for {insert date here}. I am WX0MIK and my name is Mike Wills. This season, we are covering amateur (or ham) radio.


  • Section 5.3 start talking about digital modes, something I think I'll have fun doing.
  • Especially with digital modes, you need a computer. In many cases, it doesn't matter if it's Mac or PC. There is even quite a bit for Linux.
  • The FCC limits how fast digital data can be transmitted on the different bands. You learn this in more detail in the general exam.
  • Some of the HF SSB modes are RTTY, PSK31, FT8 and WSPR, PACTOR (and it's variants), Packet Radio, JT65, and even IEEE 802.11 (wifi) adapted to run on microwave bands. I'll have to research that last one more.
  • Packet and Packet Networks
    • Packet Signals often found on simplex channels between 145.01 and 145.09 MHz. On VHF/UHF the packet is transmitted at a rate of 1200 or 9600 baud. This very closely resembles the old model baud rates.
    • This behaves much like TCP/IP where you have the header and the data. The header also contains a checksum for error detection. If errors out, the packet is requested again, much like the internet works today.
  • PSK is another mode talked about in the book. This is more like a text message over the airwaves. Only slower.
  • APRS (or Automatic Packet Reporting System) is kind of neat in that is can be linked to a GPS to send your current coordinates, speed, and direction to this network of radios and computers. Then others can track you. This is very useful in disasters.
  • Typically, you use your computer and it's soundcard for digital modes. You plug the audio from the radio into the microphone and the headphone on the PC to the mic on the radio.
  • While this isn't directly covered in the book, here is a sample of what a DMR conversation sounds like. I might have slightly fibbed to get Virginia on the mic (and really it could have been anyone), but she is very active on the MN State DMR talk group.

Wrap Up

Thank you for listening. 73 from WX0MIK.

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podcast/ddop/public/episode_201911.txt · Last modified: 2019/08/12 03:25 by mikewills